Social isolation and loneliness moderate the association between uncorrected hearing impairment and cognitive aging across 18 years

Social isolation and loneliness moderate the association between uncorrected hearing impairment and cognitive aging across 18 years | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Social isolation and loneliness moderate the association between uncorrected hearing impairment and cognitive aging across 18 years Charikleia Lampraki, Sascha Zuber, Nora Turoman, Emilie Joly-Burra, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5174604/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Hearing impairment affects a growing number of older adults and is associated with worse cognitive aging outcomes. However, the mechanisms linking hearing impairment and cognition are complex, and the role of potential moderating factors remains underexplored. This study examined whether social isolation and loneliness profiles (e.g., non-isolated but lonely) help explain why some older individuals experience faster cognitive decline as their hearing worsens, while others do not. Using longitudinal data from waves 1 to 9 of the Survey of Health, Ageing, and Retirement in Europe (SHARE), we analysed 33,741 individuals (Mage = 61.4, SD = 8.6). Multilevel modelling revealed that both levels and linear and quadratic changes in hearing impairment predicted lower cognitive performance and steeper cognitive decline. Additionally, compared to those who were non-isolated and less lonely, those in the non-isolated but lonelier profile exhibited steeper declines in episodic memory, but not executive functions, with worsening hearing. These findings highlight key psychosocial factors contributing to cognitive decline in the context of hearing impairment, underscoring the importance of targeted social and health interventions to support cognitive health in older adults. Biological sciences/Psychology Biological sciences/Psychology/Human behaviour cognitive abilities hearing difficulties psychosocial factors old age Figures Figure 1 Figure 2 Introduction Hearing impairment – comprising both partial and total inability to hear – is a condition that affects many older adults, with numbers increasing with advancing age. According to the National Institute for Deafness and Other Communication Disorders [ 1 ], around 22% of those aged 65 to 74 in the USA encounter disabling hearing loss, increasing to 55% for those 75 and older. Hearing impairment relates to adverse outcomes in various domains of life, such as cognition [ 2 – 4 ], mental health [ 5 , 6 ], and quality of life [ 7 ]. For example, Livingston et al. [ 2 ] estimated an increased risk for dementia of 90% for older adults who are impaired in their hearing capacity compared to the non-impaired. With increasing longevity, shedding light onto the mechanisms and processes that may link hearing impairment with cognitive functioning is, therefore, of the utmost importance for aging societies. The link between hearing impairment and cognitive functioning has been repeatedly observed in prior research [ 3 , 4 , 8 , 9 ] – suggesting that sensory decline can lead to poorer cognitive outcomes. However, the specific pathway between hearing impairment and cognition is complex and still lacks a fine-grained investigation of potential factors that may modulate this relationship. In this context, psychosocial factors represent an interesting target of investigation because they might be able to explain the enormous inter-individual differences observed in this area; in other words, why some older individuals with severe hearing impairment show poor cognitive functioning while others remain less impacted. With advancing age, individuals experience critical life events that tend to diminish their social network, such as retirement and bereavement [ 10 ]. Thus, two of the most important psychosocial factors that affect many aging individuals are social isolation and loneliness. Social isolation represents an objective state in which the individual has very few or none to interact with in a frequent manner, while loneliness, on the other hand, is the subjective feeling of being isolated, and stems from the imbalance between the need for socialization and the lack of it [ 11 ]. According to socioemotional selectivity theory [ 12 ], older individuals tend to reduce their social network and maintain only a small circle of meaningful and satisfying contacts, demonstrating that social isolation can be either an imposed social situation or a conscious choice in later life. Nevertheless, social isolation has been related to worse mental health and cardiovascular outcomes [ 13 ]. Loneliness can vary depending on the duration and context of the experience (i.e., situational loneliness, chronic loneliness) and has, for example, been related to a higher risk of all-cause mortality [ 14 ]. Although social isolation and loneliness are distinct phenomena, they have often been investigated concurrently as the objective and subjective form of isolation [ 15 ], forming four possible profiles: a) being non-isolated and non-lonely, b) being non-isolated but lonely (i.e., “Lonely in the Crowd”), c) being isolated but not lonely, and d) being isolated and lonely [ 16 , 17 ]. Social isolation and loneliness are significant factors linked to cognitive decline through various mechanisms [ 2 , 18 , 19 ]. For instance, isolated individuals typically have reduced social interactions – which can limit cognitive stimulation essential for maintaining brain health [ 20 ]. Similarly, such individuals typically also display more unhealthy behaviours (e.g., malnutrition) and poorer sleep, which also negatively impact cognition [ 21 – 23 ]. Loneliness has also been related to physical health issues such as cardiovascular diseases and inflammation, and to poor mental health, chronic stress, and elevated cortisol levels, all of which can further harm cognitive functioning [ 24 – 26 ]. Moreover, loneliness has been linked to detrimental changes in brain structure and reduced cognitive reserve, making the brain more vulnerable to cognitive decline [ 27 , 28 ]. Lastly, longitudinal studies and meta-analyses consistently show that social isolation and loneliness are related to greater cognitive decline [ 18 , 29 ], underscoring the importance of addressing these factors in cognitive aging research. Notably, although social isolation and loneliness have both been related to hearing impairment [ 5 ], it is still unclear a) whether social isolation and loneliness each could contribute to the link between hearing impairment and cognition and b) whether these links might differ based on whether a person is only affected by social isolation, loneliness, or both. Therefore, a more nuanced investigation is needed to identify individuals in later life that are at risk of more severe or faster cognitive decline when experiencing an increase in their hearing impairment, depending on whether they are socially isolated and/or feel lonely. Although the bilateral links between hearing impairment and cognition as well as between social isolation and loneliness and cognition are well-established separately, these phenomena have only been investigated concurrently by one previous study. Maharani et al. [ 30 ] used data from the English Longitudinal Study of Ageing to investigate the mediating role of social isolation and loneliness on the link between hearing impairment and cognition. They found that both social isolation and loneliness partly mediated the link, indicating that hearing impairment affects the social integration of the individual which leads to poorer cognitive performance. Thereby, Maharani, et al. [ 30 ] provided important first insights into the possible mechanisms between hearing impairment, social isolation, loneliness, and cognition, opening avenues for future research which we aimed to cover in the present study. We targeted several novel and conceptually as well as clinically important questions that were left unanswered by Maharani et al. (2019). First, their study focused on episodic memory as the only indicator of participants’ cognitive functioning, and it remained to be investigated whether the observed links also apply to different cognitive abilities relying on different brain networks or whether these links may be specific to certain cognitive domains. Specifically, fluid cognitive abilities, i.e., those depending on frontal networks and requiring controlled top-down processing, such as executive functions [ 31 ], are a crucial hallmark of cognitive functioning as these abilities are key for independence and autonomy and known to decline with age [ 32 , 33 ]. Therefore, here we aimed to examine potential differences between two core aspects of cognition that typically decline with age, episodic memory and executive functions. Second, Maharani et al. [ 30 ] examined cognitive decline as a function of baseline hearing impairment, social isolation and loneliness, and they operationalized hearing impairment only as a dichotomous variable, separating the severely impaired from the non-impaired. Our study aimed to investigate in more depth both interindividual differences and intraindividual changes in two core aspects of cognition as a function of changes in hearing impairment using longitudinal data from a large European dataset that covers 18 years of aging of older individuals. Third, [ 30 ] examined the role of loneliness and social integration as separate constructs but did not investigate potential interplay between the two. As the interplay of loneliness and social isolation is complex and multi-facetted, research is still lacking evidence regarding who is at greater risk of cognitive decline when hearing becomes impaired: the socially isolated but not lonely, the lonely but non-isolated, or those who are both lonely and isolated. Therefore, this study aimed to investigate these phenomena concurrently with longitudinal data that allowed us to relate the trajectories of hearing impairment and cognition (i.e., episodic memory and executive functioning) and examine whether they differ by these four intertwined profiles of social isolation and loneliness. Addressing this important gap in the literature will allow researchers and (mental) health professionals to target specific groups of social isolated and/or lonely individuals with uncorrected hearing impairment (i.e., no use of hearing aids) to delay, minimize, or prevent their cognitive decline. Drawing from the literature presented above, the present study aimed to investigate the following two main research questions: 1) Does the link between hearing impairment and cognition vary depending on specific profiles of loneliness and social isolation? 2) Are potential differences between the four loneliness and social isolation profiles consistent across cognitive abilities (i.e., episodic memory, executive functions)? Recognizing the heterogeneity of the aging process and the importance of considering both stable traits and dynamic changes in the context of aging research [ 34 , 35 ], we aimed to investigate these questions with regard to between- and within-person differences (i.e., level and change over time in hearing impairment). Finally, by deepening our understanding of the complex interactions between hearing impairment, social isolation and loneliness, and cognition in later life, we will point towards the potentially significant role of psychosocial factors in cognitive trajectories, and how they can contribute to the development of targeted interventions that promote cognitive health and improve quality of life for older adults facing hearing impairment. Results The three fully unconditional models (no predictors) revealed that the ICC (Intraclass Correlation Coefficient) for immediate recall was .48, .53 for delayed recall, and .62 for verbal fluency, indicating that 48%, 53%, and 62% of the cognitive trajectories varied across individuals, hence justifying the use of multilevel models. We therefore proceeded to more complex models to test between-subjects differences and within-subjects change. Immediate Recall The most parsimonious model for each cognitive outcome is presented in Table 1 . For immediate recall, we found between subjects’ differences in several predictors. Individuals who were younger in age, female, highly educated, and with fewer chronic conditions scored better in the immediate recall task. Similarly, individuals who were overall less impaired in hearing performed better in the immediate recall task. Regarding social isolation and loneliness, when compared to the non-isolated and less lonely profile who served as the reference, all other three profiles (i.e., individuals who were not isolated but felt lonelier than others, those who were isolated but felt less lonely than others, and those who were isolated and felt lonelier than others) had worse performance in immediate recall. However, individuals who pertained to the isolated and lonelier profile were the most impacted of all. The within-subjects effects showed that with increasing age, chronic conditions and hearing impairment, the performance of the immediate recall task decreased. In addition, we also tested a quadratic effect for hearing impairment and results indicated that it was also significant. As both the linear and the quadratic terms for hearing impairment were significant, the results indicated that as hearing impairment increased, the performance in immediate recall declined and it was followed by further decline at an accelerated rate. Regarding the interaction effects, individuals in the non-isolated but lonelier profile showed a steeper decline in immediate recall scores when hearing impairment increased, as shown also in Fig. 1 . Table 1 Multilevel model with fixed and random effects for outcomes of interest Immediate recall Delayed recall Verbal fluency Estimates CI p Estimates CI p Estimates CI p Fixed Effects (Intercept) 8.26 8.14–8.37 < 0.001 7.49 7.35–7.64 < 0.001 30.19 29.60–30.78 < 0.001 Age (M) -0.02 -0.02 – -0.02 < 0.001 -0.06 -0.06 – -0.06 < 0.001 -0.16 -0.17 – -0.15 < 0.001 Age (C) -0.05 -0.05 – -0.05 < 0.001 -0.02 -0.02 – -0.02 < 0.001 -0.06 -0.07 – -0.06 < 0.001 Sex (Females) 0.29 0.26–0.31 < 0.001 0.41 0.38–0.45 < 0.001 0.29 0.16–0.42 < 0.001 Education (High) 0.86 0.84–0.89 < 0.001 1.02 0.99–1.06 < 0.001 4.36 4.23–4.50 < 0.001 Chronic conditions (M) -0.06 -0.07 – -0.05 < 0.001 -0.09 -0.10 – -0.07 < 0.001 -0.08 -0.14 – -0.03 0.003 Chronic conditions (C) -0.02 -0.02 – -0.01 < 0.001 -0.02 -0.03 – -0.01 < 0.001 0.02 -0.01–0.05 0.243 Hearing impairment (M) -0.18 -0.20 – -0.17 < 0.001 -0.19 -0.21 – -0.17 < 0.001 -0.59 -0.68 – -0.51 < 0.001 Hearing impairment (C) -0.03 -0.05 – -0.02 < 0.001 -0.05 -0.07 – -0.03 < 0.001 -0.25 -0.29 – -0.20 < 0.001 Hearing impairment (C 2 ) -0.06 -0.07 – -0.05 < 0.001 -0.07 -0.08 – -0.05 < 0.001 -0.18 -0.23 – -0.13 < 0.001 Non-isolated and high loneliness -0.19 -0.22 – -0.17 < 0.001 -0.25 -0.29 – -0.22 < 0.001 -1.57 -1.70 – -1.44 < 0.001 Isolated and low loneliness -0.22 -0.34 – -0.10 < 0.001 -0.23 -0.39 – -0.08 0.003 -0.25 -0.88–0.38 0.444 Isolated and high loneliness -0.40 -0.50 – -0.31 < 0.001 -0.48 -0.61 – -0.35 < 0.001 -2.11 -2.63 – -1.59 < 0.001 Hearing impairment (C) * Non-isolated and high loneliness -0.06 -0.08 – -0.04 < 0.001 -0.04 -0.07 – -0.01 0.005 - - - Hearing impairment (C) * Isolated and low loneliness 0.02 -0.10–0.13 0.755 0.02 -0.11–0.15 0.768 - - - Hearing impairment (C) * Isolated and high loneliness -0.03 -0.13–0.06 0.505 -0.08 -0.19–0.03 0.159 - - - Random Effects Residual variance 1.46 2.02 22.14 Intercept 0.86 1.55 28.49 Hearing Impairment (C) slope 0.08 0.12 1.24 Hearing Impairment (C 2 ) slope 0.01 0.02 0.33 Covariance intercept*Hearing impairment (C) slope 0.11 0.14 0.04 Covariance intercept*Hearing impairment (C 2 ) slope -0.25 -0.33 -0.26 ICC 0.38 0.44 0.56 N 33726 33725 33727 Observations 137001 137039 137031 Marginal R 2 / Conditional R 2 0.193 / 0.497 0.188 / 0.541 0.161 / 0.633 Notes. M = across-waves person-mean variable (between-subjects differences) ; C = variable indicating the linear change from the person-mean (within-subjects change) ; C 2 = variable indicating the quadratic change from the person-mean (within-subjects change) ; Marginal R 2 = variance explained by fixed effects only ; Conditional R 2 = variance explained by fixed and random effects. Regarding the random effects, the within-subjects’ random variance was significant, indicating that there was significant variability in the immediate recall scores within individuals over time. Similarly, the random intercept was also significant, suggesting that there was significant variability between individuals with regards to their initial level of immediate recall scores. The random slopes of the linear and quadratic change of hearing impairment also varied significantly, indicating that the rates of change in the linear and the quadratic effects differed between individuals. Moreover, the covariances between the intercept and the slopes of linear and quadratic change in hearing impairment indicated that: 1) for individuals with higher baseline levels of immediate recall, their cognitive performance had a less steep decrease when their hearing impairment increased compared to those with lower baseline levels of immediate recall for whom the decrease was steeper; 2) for individuals with higher baseline levels of immediate recall, the curvature between the hearing impairment and immediate recall scores was less pronounced compared to those with lower baseline levels of immediate recall, for whom the curvature was more pronounced. Delayed Recall The fixed main effects findings were almost identical to the immediate recall results. Regarding the interactions, only the interaction between the linear effect of hearing impairment and the loneliness/social isolation profiles was significant and, therefore, maintained in the final model (Fig. 2 ). Similar to the immediate recall model, the “lonely in the crowd” profile (non-isolated but lonelier than others) showed a steeper decline in delayed recall scores than the non-isolated and less lonely profile. Regarding the random effects of the delayed recall model, random variance and random intercept were both significant. Similar to the immediate recall model, the random slopes of the linear and the quadratic change of hearing impairment were also significant. This suggests that the rates of change of the two effects varied across individuals. Moreover, the covariances between the intercept and the slopes of linear and quadratic change in hearing impairment were identical to those obtained for immediate recall. Verbal Fluency Similar to immediate recall, between subjects’ results indicated that individuals who were younger in age, females, highly educated and with fewer chronic conditions scored better in the verbal fluency task. Similarly, individuals who were overall less impaired in their hearing performed better in the verbal fluency task. Regarding the profiles of social isolation and loneliness, now it was both individuals who were not isolated but felt lonelier than others and those who were isolated and felt lonelier than others that had worse performance in verbal fluency compared to the non-isolated and less lonely reference profile. Regarding the within-subjects’ effects, results showed that with increasing age and hearing impairment the verbal fluency performance decreased. The change in chronic conditions was not associated to the decline in verbal fluency scores. In addition, we also tested a quadratic effect for hearing impairment and results indicated a positive and significant relation to verbal fluency. As both the linear and the quadratic terms for hearing impairment were significant and negative, the results indicated that as hearing impairment increased, verbal fluency performance dropped, which was followed by an accelerated decrease. Regarding the interaction effects between the different hearing impairment effects and the loneliness/social isolation profiles, we found that none improved the model and therefore were all excluded from further analysis. Regarding the random effects for verbal fluency, the within subjects’ variance and the intercept were significantly different from zero, suggesting that the change in verbal fluency differed between individuals. Within subjects’ baseline level was also significantly different from zero, accounting for all other confounding variables in the model. The random slopes for the linear and quadratic change in hearing impairment also varied significantly, indicating that the rate of change differed among individuals. Moreover, the covariances between the intercept and slopes of linear and quadratic change in hearing impairment indicated that: 1) for individuals with higher baseline levels of verbal fluency their cognitive performance had a less steep decrease when their hearing impairment increased compared to those with lower baseline levels of verbal fluency for whom the decrease was steeper; 2) for individuals with higher baseline levels of verbal fluency the curvature between the hearing impairment and verbal fluency scores was less pronounced compared to those with lower baseline levels of verbal fluency for whom the curvature was more pronounced. Discussion Our study investigates for the first time whether the longitudinal link between hearing impairment and cognitive outcomes was moderated by profiles of social isolation and loneliness with regard to interindividual differences and intraindividual change. Specifically, we tested to which extent the levels and trajectories of episodic memory and executive functioning were explained by hearing impairment and how they differed depending on specific profiles of social isolation and loneliness. The findings confirm that older adults with specific profiles of social isolation and loneliness have worse cognitive performance in episodic memory and executive functioning and develop steeper cognitive decline than others, highlighting the important public health challenge of identifying groups of individuals who are at risk of worse cognitive outcomes when hearing impairment worsens. Our results extend the existing literature indicating that hearing impairment is associated with poorer cognitive performance and steeper cognitive decline over time [ 2 – 4 , 8 , 9 ]. Both immediate and delayed recall (as indicators of episodic memory), as well as verbal fluency (as indicator of executive functioning), deteriorated more rapidly with increasing levels of hearing impairment. Moreover, the significant quadratic effects of hearing impairment suggest that the decline in cognitive performance accelerates as hearing impairment worsens, highlighting the negative impact of progressive sensory decline on cognitive health. Notably, the study identified significant between-subjects’ differences based on profiles of loneliness and social isolation, underscoring their critical roles in cognitive aging: Individuals who were socially isolated and lonelier showed the poorest performance in both episodic memory and executive functions, as compared to the three other profiles. However, and perhaps even more important, we found that the individuals who are more at risk for a steeper decline in episodic memory with worsening hearing impairment are those who are not isolated but feel lonelier than others. The "lonely in the crowd" profile (non-isolated but feeling lonelier) showed a steeper decline in both immediate and delayed recall, emphasizing that the subjective feeling of loneliness can significantly exacerbate cognitive decline even in the absence of objective social isolation. This aligns with previous research highlighting the detrimental effect of loneliness on mental health and cognitive functioning [ 19 , 27 ]. We also tested the interaction of the overall level of and the quadratic effect of hearing impairment with the profiles of social isolation x loneliness and found no significant effects. These findings indicate that the link between hearing impairment and cognition differs by the social isolation x loneliness profiles only in terms of the linear trend but not an accelerated change in hearing impairment: A linear increase in hearing impairment is related to a steeper cognitive decline in the “lonely in the crowd” group, while the overall hearing level and the non-linear trajectory are associated with similar levels of cognitive performance across profiles. Regarding executive functioning, the non-isolated but lonelier and the isolated and lonelier profiles performed worse compared to the non-isolated and less lonely profile. However, no significant interaction effects between the psychosocial profiles and hearing impairment were observed for this cognitive domain. This suggests that the influence of isolation and loneliness on the link between hearing impairment and cognitive decline may be more closely related to memory than to executive functioning. Yet, the verbal fluency task also required a memory contribution, to recall animal names to execute the task correctly. Perhaps what drove the differences in results across the two task types was that the recall tasks had more of a social interaction component (encoding, maintaining, and reproducing words heard by an experimenter), whereas the verbal fluency task required self-generated responses. Exploring the specific effects on different measures of executive functioning, such as attentional control, working memory, or reasoning, may thus be of interest for future research. Several potential mechanisms may be able to explain why hearing impairment and loneliness may jointly contribute to cognitive decline. For instance, drawing from the cognitive load literature [ 36 , 37 ], hearing impairment may increase the cognitive load of aging individuals, forcing them to exert more mental effort to comprehend others speaking, detracting from other cognitive processes, such as memory and executive functioning, or leading them to avoid tiring social interactions altogether. Another potential explanation may be that increasing hearing impairment and social isolation in later life may limit the opportunities for individuals to have social interactions [ 5 , 20 ] and, therefore, cognitive stimulation, which is crucial for the maintenance of cognitive health in later life. Specifically, the cognitive reserve theory argues that leisure activities and social interactions provide the context for cognitive stimulation, increasing cognitive reserve, which, in turn, helps to protect cognitive health [ 38 , 39 ]. Finally, loneliness has been related to many adverse mental and physical health outcomes, such as chronic stress, elevated cortisol levels, poor diet and sleep disturbance, which can eventually impact cognitive functioning in later life [ 24 – 26 ]. Although the current study cannot distinguish between these potential underlying mechanisms, future prospective cohort studies building on our work might one day be able to. Importantly, our study gives new insights into how the change in hearing impairment, cognitive decline and psychosocial factors interrelate. The only other study investigating these phenomena concurrently [ 30 ] tested a mediation model, showing that loneliness and social isolation mediated the link between (baseline) hearing impairment and episodic memory. Our study offers additional insights into the interplay of these phenomena with longitudinal data over a period of almost 20 years, investigating the trajectories of executive functions in addition to episodic memory, their associations with changes in hearing impairment, as well as accounting, at the same time, for the potential differences between profiles of social isolation and loneliness in later life. Lastly, we were able to identify a specific group of individuals, i.e., older adults who are “lonely in the crowd”, who are potentially more at risk of experiencing a steeper cognitive decline in later life when their hearing impairment increases. Overall, the present findings underscore the importance of targeting both hearing impairment and psychosocial factors to maintain cognitive health in older adults. Importantly, having identified the “lonely in the crowd” as the group that is most at risk of a steeper cognitive decline when hearing impairment worsens may have multiple implications in the context of prevention and intervention strategies. On the one hand, policy makers and practitioners may want to promote and facilitate easier access to hearing aids and auditory rehabilitation programs to mitigate the cognitive load associated with increasing hearing impairment. Similarly, communicating the potential impact of hearing impairment and significant benefits of hearing aids for cognitive aging to the broader public may raise awareness, limit self-stigmatising, and improve early consultation when noticing changes in one’s hearing. On the other hand, from a psychosocial perspective, our findings also show that having a mismatch between need and satisfaction of social interactions that causes loneliness [ 40 ], possibly as a result of not being able to interact as much as one wants due to hearing impairment, presents serious issues for cognitive functioning. Thus, enabling individuals to improve or maintain their hearing is crucial to avoid feeling lonely, and consequently, to continue being cognitively healthy in later life. As the maintenance of cognitive health in later life is a multifaceted and complex challenge, interventions should also aim to provide broader health management strategies, such as monitoring and treating chronic conditions, promoting healthy lifestyles and providing mental health support. Finally, as psychosocial factors are important moderators of the link between hearing impairment and cognitive health, social support programs should be developed targeting to alleviate loneliness in isolated and non-isolated individuals. While this study provides a number of novel and conceptually as well as clinically valuable insights, it is important to acknowledge some limitations. First, although this is the first study to test the interplay of hearing impairment, cognition, social isolation and loneliness with longitudinal data, one limitation is that the assessment of social isolation and loneliness profiles is cross-sectional. SHARE provides the first concurrent assessment of the social connectedness scale and loneliness in wave 6. In the future, it would be of interest to test the dynamic aspects of longitudinal change in the two psychosocial factors, providing also a distinction between those who are chronically socially isolated and/or lonely. Moreover, as loneliness can take two forms, emotional (lack of intimate partner) or social (lack of social embeddedness), it would be beneficial for future studies to investigate whether the link between hearing impairment and cognition differs by profiles of emotionally or socially lonely individuals. Another potential venue for future research may be the further investigation of these relationships in other cognitive aspects, such as working memory, as an ubiquitous cognitive process in daily life that is known to decline with advancing age [ 41 , 42 ]. Regarding hearing impairment, a limitation of this study may be that SHARE only provides subjective hearing impairment information. Studying these relationships with an objective measure of hearing impairment could be another venue of for future research. Finally, a last limitation of this study is that we offer insights for the European context exclusively. As the experience of social isolation and loneliness in older age may differ in other cultural contexts, future studies should aim to replicate these findings in other regions of the world. In conclusion, our study reveals critical insights into how the interplay between hearing impairment, social isolation, and loneliness impacts cognitive aging. We demonstrate that hearing impairment is linked to steeper declines in both episodic memory and executive functioning, with the decline accelerating as hearing impairment worsens. Notably, the subjective experience of loneliness significantly exacerbates cognitive decline, especially in episodic memory, even in the absence of objective social isolation. This finding identifies the "lonely in the crowd" profile as particularly vulnerable, emphasizing the need for targeted prevention or interventions. Addressing hearing impairment through accessible hearing aids and auditory rehabilitation, alongside interventions aiming to reduce loneliness, could help to mitigate cognitive decline in older adults. Our study underscores the importance of a holistic approach that combines auditory health with psychosocial support to maintain cognitive health in later life. Future research should further explore these dynamics across different cultural contexts and investigate additional cognitive domains to provide a more fine-grained understanding of these relationships. Methods Participants and Sample Data were derived from the Survey of Health, Ageing and Retirement in Europe (SHARE). SHARE biannually collects panel data of individuals residing in Europe and in Israel with a minimum age of 50 years. The first data collection occurred in 2004–2005 with the latest collection wave in 2020–2021 (study wave 9). SHARE collected retrospective life course data with the SHARE Life module in waves 3 and 7. Our study used data from wave 1 to wave 9, except for wave 3 in which no cognitive tests were performed. The sample used for this study included individuals aged 50 years and older with a mean age of M = 61.4 (SD = 8.6, Min = 50, Max = 99) at baseline. Participants (N = 86’676) resided in one of the 13 following countries: Austria, Belgium, Czech Republic, Denmark, France, Germany, Greece, Italy, Poland, Spain, Sweden, the Netherlands, and Switzerland. We selected these countries because they were the ones that participated consistently in the survey from the start and provided the most complete longitudinal data to investigate cognitive decline. As we focused on uncorrected hearing impairment, participants who reported that they had a hearing aid at any point during the study were excluded ( N = 5’311). The final sample consisted of 33’741 participants who had at least one observation in any of the variables used in the analysis (see Table A of Supplementary Material for a descriptives of study variables). All participants provided a written informed consent before participating to the study. In accordance with the Declaration of Helsinki for research involving humans, SHARE was approved by the Ethics Council of the Max Planck Society and Ethics Research Committees in all participating countries. Measures All measures used in this study were assessed by interviewers with the use of CAPI (Computer-Assisted Personal Interviewing), ensuring standardization and reducing potential biases related to literacy levels of participants in different regions and cultures of Europe. Outcomes: Three outcomes of cognitive functioning were assessed in every study wave and analysed: immediate recall , delayed recall [ 43 ] and verbal fluency [ 44 ]. Immediate recall assessed the extent to which the participants were able to recall 10 words immediately after they were read out by the interviewer, within 1 minute. For delayed recall, participants were again asked to recall the same 10 words within a 1-minute timeframe, after having completed other parts of the interview (approximately 10 minutes later). For both recall tasks, a higher number of recalled words indicated better cognitive functioning. For verbal fluency, participants were asked to name as many animals as possible within 60 seconds. The same version of the question was asked in every wave, and the total score counted all animals named within the 60-seconds timeframe, regardless of whether they were real or mythical, a species or a specific breed of that species, the male or female or infant name. A higher number of animals indicated better verbal fluency. Predictors: Control variables assessed demographic information and chronic conditions. Chronological age, sex (0 = males, 1 = females), and educational level were measured at baseline. Educational level was calculated as a binary variable based on the median split of the categorical variable measuring education with the 1997 version of the International Standard Classification of Education [ 45 ], with 0 = low educational level and 1 = high educational level. Chronic conditions were assessed at each wave in the physical health module with the following question: “Some people suffer from chronic or long-term health problems. By chronic or long-term we mean it has troubled you over a period of time or is likely to affect you over a period of time. Do you have any such health problems, illness, disability or infirmity?”. If an individual reported a new condition, this information was added to their existing number of chronic conditions. Hearing impairment was assessed in every wave. Participants had to indicate how their hearing was on a 5-point likert scale, ranging from 1 = Excellent to 5 = Poor . Higher scores indicated more severe subjective hearing impairment. Social Isolation was assessed with the social connectedness scale [ 46 , 47 ] from wave 6. This was the first wave in which both social isolation and loneliness were concurrently measured. The social connectedness scale is a summary scale incorporating five social network characteristics into one composite score. The characteristics include: 1) network size (representing the number of individuals that the participant cited), 2) proximity (representing the number of cited individuals living within a 25 km range from the participant), 3) frequency of contact (representing the number of cited individuals with a least weekly contact to the participant), 4) support (representing the number of cited individuals with very or extremely close emotional ties), and, lastly, 5) diversity (representing the number of different types of relationships within the network). Network size, proximity, frequency of contact and support were assessed from 0 to 4 with 0 = 0 persons cited and 4 = 6–7 persons cited. Diversity also ranged from 0 to 4, with 4 representing the highest diversity in the network comprising of all 4 possible categories (i.e., spouse, other family including children, friend, and other). The final scale ranged from 0 = no social connectedness (0 social network members) to 4 = high social connectedness. In order to create an indicator of social isolation, a binary variable was computed based on the social connectedness scale with 1 representing individuals with no social connections (scored 0 in social connectedness scale) and 0 representing individuals having scored 1 and above in the social connectedness scale. Loneliness was assessed with the 3-item UCLA scale [ 48 ] at wave 6. The mean composite score ranged from 3 = not lonely to 9 = very lonely . Higher values indicated higher loneliness. A binary variable was computed based on the median value of the UCLA score with 0 = low loneliness (scored less than 4 in the UCLA) and 1 = high loneliness (scored equal or more than 4 in the UCLA). Social Isolation x Loneliness profiles . Inspired by past research [ 15 – 17 ], we created four profiles based on the two binary indicators of social isolation and loneliness: 1) non-isolated and low loneliness, 2) non-isolated and high loneliness, 3) isolated and low loneliness, 4) isolated and high loneliness. Analytical Strategy We tested between-subjects’ differences and within-subjects' change in immediate and delayed recall, as well as in verbal fluency, using multilevel modelling. To facilitate the interpretability of the results regarding the within subjects’ change, we person-centred the time-varying variables (i.e., age, chronic conditions and hearing impairment). To investigate between-subjects differences of the time-varying variables we also calculated and included the across-waves person-mean in the models [ 49 ]. Sex and educational level were measured in wave one and included in the model as time-invariant non-centred factors. Regarding hearing impairment, we were interested in the extent to which the linear and the quadratic change may relate to cognitive outcomes and therefore included a linear and a quadratic term. We present the final and most parsimonious models (i.e., the ones with the best fit) which tested fixed and random effects, as well as interaction terms (see below). Estimates are reported unstandardized. For the fixed effects, we reported 95% Confidence Intervals (CI) and p values. The fit of the models was tested with Akaike’s Information Criterion (AIC), Bayesian Information Criterion (BIC) and − 2 log likelihood (-2LL) fit indices (see supplementary material). The Marginal R2 was used to assess the variance explained only by the fixed effects and the Conditional R2 was used to assess the variance explained by both the fixed and the random effects in each model. We included the different parameters in the model in a stepwise procedure: First, to verify the extent to which between-subjects differences and within-subjects change were related to the hierarchical clustering of the data, we tested a fully unconditional model, with no predictors included. Then, we added the fixed effects for all variables in the model, continuing with the inclusion of the random effects. The random effects included a random intercept and slope for the linear change and quadratic change of hearing impairment, allowing for individuals to have different baseline levels as well as different cognitive trajectories as a function of linear and quadratic change in hearing impairment. Finally, we tested the three interaction terms of interest one by one, namely the mean, change and squared change parameters of hearing impairment with the profiles of loneliness/social isolation. The final models presented have retained only the interaction effects that improved the model fit. All models were tested using Restricted Maximum Likelihood estimation method. All analyses were conducted with R [ 50 ], and the lme4 package [ 51 ]. Declarations Author Contribution CL and AI conceived the study; CL performed the statistical analysis and drafted the manuscript; SZ and NT helped draft the manuscript; EJ-B, MM, CS, GL, AR, MK and AI revised the manuscript. All authors have read and approved the final version of the manuscript and agree with the order of presentation of the authors. Acknowledgement This work was supported by the Swiss National Centre of Competence in Research LIVES – Overcoming vulnerability: Life course perspectives, which is financed by the Swiss National Science Foundation (grant number: 51NF40-185901). The authors are grateful to the Swiss National Science Foundation for its financial assistance. Data Availability The data is freely accessible. 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Developmental change and intraindividual variability: relating cognitive aging to cognitive plasticity, cardiovascular lability, and emotional diversity. Psychol. Aging . 26 , 363 (2011). Sliwinski, M., Hoffman, L. & Hofer, S. M. Evaluating convergence of within-person change and between-person age differences in age-heterogeneous longitudinal studies. Res. Hum. Dev. 7 , 45–60 (2010). Heinrich, A., Ferguson, M. A. & Mattys, S. L. Effects of cognitive load on pure-tone audiometry thresholds in younger and older adults. Ear Hear. 41 , 907–917 (2020). Silva, J. S. C. D. et al. Load effect on what-where-when memory in younger and older adults. Aging Neuropsychol. Cognition . 27 , 841–853 (2020). Ihle, A. & Kliegel, M. What do individual reserves tell us about vulnerable ageing? Lancet Healthy Longev. 2 , e181–e182 (2021). Sauter, J. et al. Interactional effects between relational and cognitive reserves on decline in executive functioning. Journals Gerontology: Ser. B . 76 , 1523–1532 (2021). Weiss, R. Loneliness: The experience of emotional and social isolation (MIT Press, 1975). Babcock, R. L. & Salthouse, T. A. Effects of increased processing demands on age differences in working memory. Psychol. Aging . 5 , 421 (1990). Craik, F. I., Luo, L. & Sakuta, Y. Effects of aging and divided attention on memory for items and their contexts. Psychol. Aging . 25 , 968 (2010). Harris, S. & Dowson, J. Recall of a 10-word list in the assessment of dementia in the elderly. Br. J. Psychiatry . 141 , 524–527 (1982). Rosen, W. G. Verbal fluency in aging and dementia. J. Clin. Exp. Neuropsychol. 2 , 135–146 (1980). UNESCO United Nations Educational, S. & & Organization, C. in Advances in Cross-National Comparison: A European Working Book for Demographic and Socio-Economic Variables 195–220 (Springer, 2003). Litwin, H. & Stoeckel, K. J. Engagement and social capital as elements of active ageing: an analysis of older europeans. Sociologia e politiche sociali (2015). Malter, F. & Börsch-Supan, A. SHARE wave 6: panel innovations and collecting dried blood spots. Munich: Munich Cent. Econ. Aging (MEA) (2017). Hughes, M. E., Waite, L. J., Hawkley, L. C. & Cacioppo, J. T. A short scale for measuring loneliness in large surveys: Results from two population-based studies. Res. aging . 26 , 655–672 (2004). Hoffman, L. & Stawski, R. S. Persons as contexts: Evaluating between-person and within-person effects in longitudinal analysis. Res. Hum. Dev. 6 , 97–120 (2009). Core Team, R. RR foundation for statistical computing Vienna, Austria,. (2013). Bates, D. et al. Package ‘lme4’. convergence 12, 2 (2015). Additional Declarations No competing interests reported. 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11:23:05","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-5174604/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5174604/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":69935358,"identity":"6af6bd0c-88ae-429b-bc58-9612eee2fb19","added_by":"auto","created_at":"2024-11-26 18:53:52","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":11587,"visible":true,"origin":"","legend":"\u003cp\u003eImmediate recall with hearing impairment (linear change centred at the person’s mean) by loneliness and isolation profiles\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5174604/v1/ad15f57778e0098306ed0b58.png"},{"id":69935357,"identity":"b0c003c5-093d-40ae-8d8d-94e56458b38a","added_by":"auto","created_at":"2024-11-26 18:53:52","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":16104,"visible":true,"origin":"","legend":"\u003cp\u003eDelayed recall with hearing impairment (linear change centred at the person’s mean) by loneliness and isolation profiles\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-5174604/v1/fe4aa6ae05d626a59069324d.png"},{"id":71477159,"identity":"eca19b08-a4f5-4cdf-bde6-bc9adf7d93ed","added_by":"auto","created_at":"2024-12-16 05:25:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":681743,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5174604/v1/b0eb0d09-361c-481e-8bb9-17123096be36.pdf"},{"id":69935359,"identity":"ddebfb5f-aad3-4504-8adc-ef142c6e2a10","added_by":"auto","created_at":"2024-11-26 18:53:53","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":26067,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-5174604/v1/214231043e6d0d5c6df20b17.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Social isolation and loneliness moderate the association between uncorrected hearing impairment and cognitive aging across 18 years","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHearing impairment \u0026ndash; comprising both partial and total inability to hear \u0026ndash; is a condition that affects many older adults, with numbers increasing with advancing age. According to the National Institute for Deafness and Other Communication Disorders [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], around 22% of those aged 65 to 74 in the USA encounter disabling hearing loss, increasing to 55% for those 75 and older. Hearing impairment relates to adverse outcomes in various domains of life, such as cognition [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], mental health [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], and quality of life [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. For example, Livingston et al. [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] estimated an increased risk for dementia of 90% for older adults who are impaired in their hearing capacity compared to the non-impaired. With increasing longevity, shedding light onto the mechanisms and processes that may link hearing impairment with cognitive functioning is, therefore, of the utmost importance for aging societies. The link between hearing impairment and cognitive functioning has been repeatedly observed in prior research [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] \u0026ndash; suggesting that sensory decline can lead to poorer cognitive outcomes. However, the specific pathway between hearing impairment and cognition is complex and still lacks a fine-grained investigation of potential factors that may modulate this relationship.\u003c/p\u003e \u003cp\u003eIn this context, psychosocial factors represent an interesting target of investigation because they might be able to explain the enormous inter-individual differences observed in this area; in other words, why some older individuals with severe hearing impairment show poor cognitive functioning while others remain less impacted. With advancing age, individuals experience critical life events that tend to diminish their social network, such as retirement and bereavement [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Thus, two of the most important psychosocial factors that affect many aging individuals are social isolation and loneliness. Social isolation represents an \u003cem\u003eobjective state\u003c/em\u003e in which the individual has very few or none to interact with in a frequent manner, while loneliness, on the other hand, is the \u003cem\u003esubjective feeling\u003c/em\u003e of being isolated, and stems from the imbalance between the need for socialization and the lack of it [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. According to socioemotional selectivity theory [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], older individuals tend to reduce their social network and maintain only a small circle of meaningful and satisfying contacts, demonstrating that social isolation can be either an imposed social situation or a conscious choice in later life. Nevertheless, social isolation has been related to worse mental health and cardiovascular outcomes [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Loneliness can vary depending on the duration and context of the experience (i.e., situational loneliness, chronic loneliness) and has, for example, been related to a higher risk of all-cause mortality [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Although social isolation and loneliness are distinct phenomena, they have often been investigated concurrently as the objective and subjective form of isolation [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], forming four possible profiles: a) being non-isolated and non-lonely, b) being non-isolated but lonely (i.e., \u0026ldquo;Lonely in the Crowd\u0026rdquo;), c) being isolated but not lonely, and d) being isolated and lonely [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSocial isolation and loneliness are significant factors linked to cognitive decline through various mechanisms [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. For instance, isolated individuals typically have reduced social interactions \u0026ndash; which can limit cognitive stimulation essential for maintaining brain health [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Similarly, such individuals typically also display more unhealthy behaviours (e.g., malnutrition) and poorer sleep, which also negatively impact cognition [\u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Loneliness has also been related to physical health issues such as cardiovascular diseases and inflammation, and to poor mental health, chronic stress, and elevated cortisol levels, all of which can further harm cognitive functioning [\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Moreover, loneliness has been linked to detrimental changes in brain structure and reduced cognitive reserve, making the brain more vulnerable to cognitive decline [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Lastly, longitudinal studies and meta-analyses consistently show that social isolation and loneliness are related to greater cognitive decline [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], underscoring the importance of addressing these factors in cognitive aging research. Notably, although social isolation and loneliness have both been related to hearing impairment [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], it is still unclear a) whether social isolation and loneliness each could contribute to the link between hearing impairment and cognition and b) whether these links might differ based on whether a person is only affected by social isolation, loneliness, or both. Therefore, a more nuanced investigation is needed to identify individuals in later life that are at risk of more severe or faster cognitive decline when experiencing an increase in their hearing impairment, depending on whether they are socially isolated and/or feel lonely.\u003c/p\u003e \u003cp\u003eAlthough the bilateral links between hearing impairment and cognition as well as between social isolation and loneliness and cognition are well-established separately, these phenomena have only been investigated concurrently by one previous study. Maharani et al. [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] used data from the English Longitudinal Study of Ageing to investigate the mediating role of social isolation and loneliness on the link between hearing impairment and cognition. They found that both social isolation and loneliness partly mediated the link, indicating that hearing impairment affects the social integration of the individual which leads to poorer cognitive performance. Thereby, Maharani, et al. [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] provided important first insights into the possible mechanisms between hearing impairment, social isolation, loneliness, and cognition, opening avenues for future research which we aimed to cover in the present study. We targeted several novel and conceptually as well as clinically important questions that were left unanswered by Maharani et al. (2019). First, their study focused on episodic memory as the only indicator of participants\u0026rsquo; cognitive functioning, and it remained to be investigated whether the observed links also apply to different cognitive abilities relying on different brain networks or whether these links may be specific to certain cognitive domains. Specifically, fluid cognitive abilities, i.e., those depending on frontal networks and requiring controlled top-down processing, such as executive functions [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e], are a crucial hallmark of cognitive functioning as these abilities are key for independence and autonomy and known to decline with age [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Therefore, here we aimed to examine potential differences between two core aspects of cognition that typically decline with age, episodic memory and executive functions.\u003c/p\u003e \u003cp\u003eSecond, Maharani et al. [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] examined cognitive decline as a function of baseline hearing impairment, social isolation and loneliness, and they operationalized hearing impairment only as a dichotomous variable, separating the severely impaired from the non-impaired. Our study aimed to investigate in more depth both interindividual differences and intraindividual changes in two core aspects of cognition as a function of changes in hearing impairment using \u003cem\u003elongitudinal\u003c/em\u003e data from a large European dataset that covers 18 years of aging of older individuals.\u003c/p\u003e \u003cp\u003eThird, [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] examined the role of loneliness and social integration as separate constructs but did not investigate potential interplay between the two. As the interplay of loneliness and social isolation is complex and multi-facetted, research is still lacking evidence regarding who is at greater risk of cognitive decline when hearing becomes impaired: the socially isolated but not lonely, the lonely but non-isolated, or those who are both lonely and isolated. Therefore, this study aimed to investigate these phenomena concurrently with longitudinal data that allowed us to relate the trajectories of hearing impairment and cognition (i.e., episodic memory and executive functioning) and examine whether they differ by these four intertwined profiles of social isolation and loneliness. Addressing this important gap in the literature will allow researchers and (mental) health professionals to target specific groups of social isolated and/or lonely individuals with uncorrected hearing impairment (i.e., no use of hearing aids) to delay, minimize, or prevent their cognitive decline.\u003c/p\u003e \u003cp\u003eDrawing from the literature presented above, the present study aimed to investigate the following two main research questions: 1) Does the link between hearing impairment and cognition vary depending on specific profiles of loneliness and social isolation? 2) Are potential differences between the four loneliness and social isolation profiles consistent across cognitive abilities (i.e., episodic memory, executive functions)? Recognizing the heterogeneity of the aging process and the importance of considering both stable traits and dynamic changes in the context of aging research [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e], we aimed to investigate these questions with regard to between- and within-person differences (i.e., level and change over time in hearing impairment). Finally, by deepening our understanding of the complex interactions between hearing impairment, social isolation and loneliness, and cognition in later life, we will point towards the potentially significant role of psychosocial factors in cognitive trajectories, and how they can contribute to the development of targeted interventions that promote cognitive health and improve quality of life for older adults facing hearing impairment.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe three fully unconditional models (no predictors) revealed that the ICC (Intraclass Correlation Coefficient) for immediate recall was .48, .53 for delayed recall, and .62 for verbal fluency, indicating that 48%, 53%, and 62% of the cognitive trajectories varied across individuals, hence justifying the use of multilevel models. We therefore proceeded to more complex models to test between-subjects differences and within-subjects change.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eImmediate Recall\u003c/h2\u003e \u003cp\u003eThe most parsimonious model for each cognitive outcome is presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. For immediate recall, we found between subjects\u0026rsquo; differences in several predictors. Individuals who were younger in age, female, highly educated, and with fewer chronic conditions scored better in the immediate recall task. Similarly, individuals who were overall less impaired in hearing performed better in the immediate recall task. Regarding social isolation and loneliness, when compared to the non-isolated and less lonely profile who served as the reference, all other three profiles (i.e., individuals who were not isolated but felt lonelier than others, those who were isolated but felt less lonely than others, and those who were isolated and felt lonelier than others) had worse performance in immediate recall. However, individuals who pertained to the isolated and lonelier profile were the most impacted of all. The within-subjects effects showed that with increasing age, chronic conditions and hearing impairment, the performance of the immediate recall task decreased. In addition, we also tested a quadratic effect for hearing impairment and results indicated that it was also significant. As both the linear and the quadratic terms for hearing impairment were significant, the results indicated that as hearing impairment increased, the performance in immediate recall declined and it was followed by further decline at an accelerated rate. Regarding the interaction effects, individuals in the non-isolated but lonelier profile showed a steeper decline in immediate recall scores when hearing impairment increased, as shown also in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultilevel model with fixed and random effects for outcomes of interest\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eImmediate recall\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003eDelayed recall\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003eVerbal fluency\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eEstimates\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eCI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eEstimates\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eCI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cem\u003eEstimates\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cem\u003eCI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFixed Effects\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(Intercept)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.14\u0026ndash;8.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.35\u0026ndash;7.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e 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align=\"left\" colname=\"c8\"\u003e \u003cp\u003e4.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e4.23\u0026ndash;4.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChronic conditions (M)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.07\u0026nbsp;\u0026ndash;\u0026nbsp;-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.10\u0026nbsp;\u0026ndash;\u0026nbsp;-0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-0.14\u0026nbsp;\u0026ndash;\u0026nbsp;-0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChronic conditions (C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.02\u0026nbsp;\u0026ndash;\u0026nbsp;-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.03\u0026nbsp;\u0026ndash;\u0026nbsp;-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-0.01\u0026ndash;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.243\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing impairment (M)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.20\u0026nbsp;\u0026ndash;\u0026nbsp;-0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.21\u0026nbsp;\u0026ndash;\u0026nbsp;-0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-0.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-0.68\u0026nbsp;\u0026ndash;\u0026nbsp;-0.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing impairment (C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.05\u0026nbsp;\u0026ndash;\u0026nbsp;-0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.07\u0026nbsp;\u0026ndash;\u0026nbsp;-0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-0.29\u0026nbsp;\u0026ndash;\u0026nbsp;-0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing impairment (C\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.07\u0026nbsp;\u0026ndash;\u0026nbsp;-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.08\u0026nbsp;\u0026ndash;\u0026nbsp;-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-0.23\u0026nbsp;\u0026ndash;\u0026nbsp;-0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-isolated and high loneliness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.22\u0026nbsp;\u0026ndash;\u0026nbsp;-0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.29\u0026nbsp;\u0026ndash;\u0026nbsp;-0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-1.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-1.70\u0026nbsp;\u0026ndash;\u0026nbsp;-1.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIsolated and low loneliness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.34\u0026nbsp;\u0026ndash;\u0026nbsp;-0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.39\u0026nbsp;\u0026ndash;\u0026nbsp;-0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-0.88\u0026ndash;0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.444\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIsolated and high loneliness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.50\u0026nbsp;\u0026ndash;\u0026nbsp;-0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.61\u0026nbsp;\u0026ndash;\u0026nbsp;-0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-2.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-2.63\u0026nbsp;\u0026ndash;\u0026nbsp;-1.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing impairment (C) * Non-isolated and high loneliness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.08\u0026nbsp;\u0026ndash;\u0026nbsp;-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.07\u0026nbsp;\u0026ndash;\u0026nbsp;-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e0.005\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing impairment (C) * Isolated and low loneliness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.10\u0026ndash;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.755\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.11\u0026ndash;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.768\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing impairment (C) * Isolated and high loneliness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.13\u0026ndash;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.505\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.19\u0026ndash;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.159\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRandom Effects\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResidual variance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e1.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e2.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e22.14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntercept\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e0.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e1.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e28.49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing Impairment (C) slope\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e1.24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHearing Impairment (C\u003csup\u003e2\u003c/sup\u003e) slope\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCovariance intercept*Hearing impairment (C) slope\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCovariance intercept*Hearing impairment (C\u003csup\u003e2\u003c/sup\u003e) slope\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e-0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e-0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e-0.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eICC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e0.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e0.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e33726\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e33725\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e33727\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eObservations\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e137001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e137039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e137031\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarginal R\u003csup\u003e2\u003c/sup\u003e\u0026nbsp;/ Conditional R\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e0.193 / 0.497\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e0.188 / 0.541\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e \u003cp\u003e0.161 / 0.633\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"10\" nameend=\"c10\" namest=\"c1\"\u003e \u003cp\u003eNotes. M\u0026thinsp;=\u0026thinsp;\u003cem\u003eacross-waves person-mean variable (between-subjects differences)\u003c/em\u003e; C\u0026thinsp;=\u0026thinsp;\u003cem\u003evariable indicating the linear change from the person-mean (within-subjects change)\u003c/em\u003e; C\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003evariable indicating the quadratic change from the person-mean (within-subjects change)\u003c/em\u003e; Marginal R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003evariance explained by fixed effects only\u003c/em\u003e; Conditional R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003evariance explained by fixed and random effects.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRegarding the random effects, the within-subjects\u0026rsquo; random variance was significant, indicating that there was significant variability in the immediate recall scores within individuals over time. Similarly, the random intercept was also significant, suggesting that there was significant variability between individuals with regards to their initial level of immediate recall scores. The random slopes of the linear and quadratic change of hearing impairment also varied significantly, indicating that the rates of change in the linear and the quadratic effects differed between individuals. Moreover, the covariances between the intercept and the slopes of linear and quadratic change in hearing impairment indicated that: 1) for individuals with higher baseline levels of immediate recall, their cognitive performance had a less steep decrease when their hearing impairment increased compared to those with lower baseline levels of immediate recall for whom the decrease was steeper; 2) for individuals with higher baseline levels of immediate recall, the curvature between the hearing impairment and immediate recall scores was less pronounced compared to those with lower baseline levels of immediate recall, for whom the curvature was more pronounced.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eDelayed Recall\u003c/h3\u003e\n\u003cp\u003eThe fixed main effects findings were almost identical to the immediate recall results. Regarding the interactions, only the interaction between the linear effect of hearing impairment and the loneliness/social isolation profiles was significant and, therefore, maintained in the final model (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Similar to the immediate recall model, the \u0026ldquo;lonely in the crowd\u0026rdquo; profile (non-isolated but lonelier than others) showed a steeper decline in delayed recall scores than the non-isolated and less lonely profile.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRegarding the random effects of the delayed recall model, random variance and random intercept were both significant. Similar to the immediate recall model, the random slopes of the linear and the quadratic change of hearing impairment were also significant. This suggests that the rates of change of the two effects varied across individuals. Moreover, the covariances between the intercept and the slopes of linear and quadratic change in hearing impairment were identical to those obtained for immediate recall.\u003c/p\u003e\n\u003ch3\u003eVerbal Fluency\u003c/h3\u003e\n\u003cp\u003e Similar to immediate recall, between subjects\u0026rsquo; results indicated that individuals who were younger in age, females, highly educated and with fewer chronic conditions scored better in the verbal fluency task. Similarly, individuals who were overall less impaired in their hearing performed better in the verbal fluency task. Regarding the profiles of social isolation and loneliness, now it was both individuals who were not isolated but felt lonelier than others and those who were isolated and felt lonelier than others that had worse performance in verbal fluency compared to the non-isolated and less lonely reference profile.\u003c/p\u003e \u003cp\u003eRegarding the within-subjects\u0026rsquo; effects, results showed that with increasing age and hearing impairment the verbal fluency performance decreased. The change in chronic conditions was not associated to the decline in verbal fluency scores. In addition, we also tested a quadratic effect for hearing impairment and results indicated a positive and significant relation to verbal fluency. As both the linear and the quadratic terms for hearing impairment were significant and negative, the results indicated that as hearing impairment increased, verbal fluency performance dropped, which was followed by an accelerated decrease. Regarding the interaction effects between the different hearing impairment effects and the loneliness/social isolation profiles, we found that none improved the model and therefore were all excluded from further analysis.\u003c/p\u003e \u003cp\u003e Regarding the random effects for verbal fluency, the within subjects\u0026rsquo; variance and the intercept were significantly different from zero, suggesting that the change in verbal fluency differed between individuals. Within subjects\u0026rsquo; baseline level was also significantly different from zero, accounting for all other confounding variables in the model. The random slopes for the linear and quadratic change in hearing impairment also varied significantly, indicating that the rate of change differed among individuals. Moreover, the covariances between the intercept and slopes of linear and quadratic change in hearing impairment indicated that: 1) for individuals with higher baseline levels of verbal fluency their cognitive performance had a less steep decrease when their hearing impairment increased compared to those with lower baseline levels of verbal fluency for whom the decrease was steeper; 2) for individuals with higher baseline levels of verbal fluency the curvature between the hearing impairment and verbal fluency scores was less pronounced compared to those with lower baseline levels of verbal fluency for whom the curvature was more pronounced.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur study investigates for the first time whether the longitudinal link between hearing impairment and cognitive outcomes was moderated by profiles of social isolation and loneliness with regard to interindividual differences and intraindividual change. Specifically, we tested to which extent the levels and trajectories of episodic memory and executive functioning were explained by hearing impairment and how they differed depending on specific profiles of social isolation and loneliness. The findings confirm that older adults with specific profiles of social isolation and loneliness have worse cognitive performance in episodic memory and executive functioning and develop steeper cognitive decline than others, highlighting the important public health challenge of identifying groups of individuals who are at risk of worse cognitive outcomes when hearing impairment worsens.\u003c/p\u003e \u003cp\u003eOur results extend the existing literature indicating that hearing impairment is associated with poorer cognitive performance and steeper cognitive decline over time [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Both immediate and delayed recall (as indicators of episodic memory), as well as verbal fluency (as indicator of executive functioning), deteriorated more rapidly with increasing levels of hearing impairment. Moreover, the significant quadratic effects of hearing impairment suggest that the decline in cognitive performance accelerates as hearing impairment worsens, highlighting the negative impact of progressive sensory decline on cognitive health.\u003c/p\u003e \u003cp\u003eNotably, the study identified significant between-subjects\u0026rsquo; differences based on profiles of loneliness and social isolation, underscoring their critical roles in cognitive aging: Individuals who were socially isolated and lonelier showed the poorest performance in both episodic memory and executive functions, as compared to the three other profiles. However, and perhaps even more important, we found that the individuals who are more at risk for a steeper \u003cem\u003edecline\u003c/em\u003e in episodic memory with worsening hearing impairment are those who are not isolated but feel lonelier than others. The \"lonely in the crowd\" profile (non-isolated but feeling lonelier) showed a steeper decline in both immediate and delayed recall, emphasizing that the subjective feeling of loneliness can significantly exacerbate cognitive decline even in the absence of objective social isolation. This aligns with previous research highlighting the detrimental effect of loneliness on mental health and cognitive functioning [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. We also tested the interaction of the overall level of and the quadratic effect of hearing impairment with the profiles of social isolation x loneliness and found no significant effects. These findings indicate that the link between hearing impairment and cognition differs by the social isolation x loneliness profiles only in terms of the linear trend but not an accelerated change in hearing impairment: A linear increase in hearing impairment is related to a steeper cognitive decline in the \u0026ldquo;lonely in the crowd\u0026rdquo; group, while the overall hearing level and the non-linear trajectory are associated with similar levels of cognitive performance across profiles. Regarding executive functioning, the non-isolated but lonelier and the isolated and lonelier profiles performed worse compared to the non-isolated and less lonely profile. However, no significant interaction effects between the psychosocial profiles and hearing impairment were observed for this cognitive domain. This suggests that the influence of isolation and loneliness on the link between hearing impairment and cognitive decline may be more closely related to memory than to executive functioning. Yet, the verbal fluency task also required a memory contribution, to recall animal names to execute the task correctly. Perhaps what drove the differences in results across the two task types was that the recall tasks had more of a social interaction component (encoding, maintaining, and reproducing words heard by an experimenter), whereas the verbal fluency task required self-generated responses. Exploring the specific effects on different measures of executive functioning, such as attentional control, working memory, or reasoning, may thus be of interest for future research.\u003c/p\u003e \u003cp\u003eSeveral potential mechanisms may be able to explain why hearing impairment and loneliness may jointly contribute to cognitive decline. For instance, drawing from the cognitive load literature [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e], hearing impairment may increase the cognitive load of aging individuals, forcing them to exert more mental effort to comprehend others speaking, detracting from other cognitive processes, such as memory and executive functioning, or leading them to avoid tiring social interactions altogether. Another potential explanation may be that increasing hearing impairment and social isolation in later life may limit the opportunities for individuals to have social interactions [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] and, therefore, cognitive stimulation, which is crucial for the maintenance of cognitive health in later life. Specifically, the cognitive reserve theory argues that leisure activities and social interactions provide the context for cognitive stimulation, increasing cognitive reserve, which, in turn, helps to protect cognitive health [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. Finally, loneliness has been related to many adverse mental and physical health outcomes, such as chronic stress, elevated cortisol levels, poor diet and sleep disturbance, which can eventually impact cognitive functioning in later life [\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Although the current study cannot distinguish between these potential underlying mechanisms, future prospective cohort studies building on our work might one day be able to.\u003c/p\u003e \u003cp\u003eImportantly, our study gives new insights into how the change in hearing impairment, cognitive decline and psychosocial factors interrelate. The only other study investigating these phenomena concurrently [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] tested a mediation model, showing that loneliness and social isolation mediated the link between (baseline) hearing impairment and episodic memory. Our study offers additional insights into the interplay of these phenomena with longitudinal data over a period of almost 20 years, investigating the trajectories of executive functions in addition to episodic memory, their associations with changes in hearing impairment, as well as accounting, at the same time, for the potential differences between profiles of social isolation and loneliness in later life. Lastly, we were able to identify a specific group of individuals, i.e., older adults who are \u0026ldquo;lonely in the crowd\u0026rdquo;, who are potentially more at risk of experiencing a steeper cognitive decline in later life when their hearing impairment increases. Overall, the present findings underscore the importance of targeting both hearing impairment and psychosocial factors to maintain cognitive health in older adults. Importantly, having identified the \u0026ldquo;lonely in the crowd\u0026rdquo; as the group that is most at risk of a steeper cognitive decline when hearing impairment worsens may have multiple implications in the context of prevention and intervention strategies. On the one hand, policy makers and practitioners may want to promote and facilitate easier access to hearing aids and auditory rehabilitation programs to mitigate the cognitive load associated with increasing hearing impairment. Similarly, communicating the potential impact of hearing impairment and significant benefits of hearing aids for cognitive aging to the broader public may raise awareness, limit self-stigmatising, and improve early consultation when noticing changes in one\u0026rsquo;s hearing. On the other hand, from a psychosocial perspective, our findings also show that having a mismatch between need and satisfaction of social interactions that causes loneliness [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e], possibly as a result of not being able to interact as much as one wants due to hearing impairment, presents serious issues for cognitive functioning. Thus, enabling individuals to improve or maintain their hearing is crucial to avoid feeling lonely, and consequently, to continue being cognitively healthy in later life. As the maintenance of cognitive health in later life is a multifaceted and complex challenge, interventions should also aim to provide broader health management strategies, such as monitoring and treating chronic conditions, promoting healthy lifestyles and providing mental health support. Finally, as psychosocial factors are important moderators of the link between hearing impairment and cognitive health, social support programs should be developed targeting to alleviate loneliness in isolated and non-isolated individuals.\u003c/p\u003e \u003cp\u003eWhile this study provides a number of novel and conceptually as well as clinically valuable insights, it is important to acknowledge some limitations. First, although this is the first study to test the interplay of hearing impairment, cognition, social isolation and loneliness with longitudinal data, one limitation is that the assessment of social isolation and loneliness profiles is cross-sectional. SHARE provides the first concurrent assessment of the social connectedness scale and loneliness in wave 6. In the future, it would be of interest to test the dynamic aspects of longitudinal change in the two psychosocial factors, providing also a distinction between those who are chronically socially isolated and/or lonely. Moreover, as loneliness can take two forms, emotional (lack of intimate partner) or social (lack of social embeddedness), it would be beneficial for future studies to investigate whether the link between hearing impairment and cognition differs by profiles of emotionally or socially lonely individuals. Another potential venue for future research may be the further investigation of these relationships in other cognitive aspects, such as working memory, as an ubiquitous cognitive process in daily life that is known to decline with advancing age [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. Regarding hearing impairment, a limitation of this study may be that SHARE only provides subjective hearing impairment information. Studying these relationships with an objective measure of hearing impairment could be another venue of for future research. Finally, a last limitation of this study is that we offer insights for the European context exclusively. As the experience of social isolation and loneliness in older age may differ in other cultural contexts, future studies should aim to replicate these findings in other regions of the world.\u003c/p\u003e \u003cp\u003eIn conclusion, our study reveals critical insights into how the interplay between hearing impairment, social isolation, and loneliness impacts cognitive aging. We demonstrate that hearing impairment is linked to steeper declines in both episodic memory and executive functioning, with the decline accelerating as hearing impairment worsens. Notably, the subjective experience of loneliness significantly exacerbates cognitive decline, especially in episodic memory, even in the absence of objective social isolation. This finding identifies the \"lonely in the crowd\" profile as particularly vulnerable, emphasizing the need for targeted prevention or interventions. Addressing hearing impairment through accessible hearing aids and auditory rehabilitation, alongside interventions aiming to reduce loneliness, could help to mitigate cognitive decline in older adults. Our study underscores the importance of a holistic approach that combines auditory health with psychosocial support to maintain cognitive health in later life. Future research should further explore these dynamics across different cultural contexts and investigate additional cognitive domains to provide a more fine-grained understanding of these relationships.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eParticipants and Sample\u003c/h2\u003e \u003cp\u003eData were derived from the Survey of Health, Ageing and Retirement in Europe (SHARE). SHARE biannually collects panel data of individuals residing in Europe and in Israel with a minimum age of 50 years. The first data collection occurred in 2004\u0026ndash;2005 with the latest collection wave in 2020\u0026ndash;2021 (study wave 9). SHARE collected retrospective life course data with the SHARE Life module in waves 3 and 7. Our study used data from wave 1 to wave 9, except for wave 3 in which no cognitive tests were performed.\u003c/p\u003e \u003cp\u003eThe sample used for this study included individuals aged 50 years and older with a mean age of M\u0026thinsp;=\u0026thinsp;61.4 (SD\u0026thinsp;=\u0026thinsp;8.6, Min\u0026thinsp;=\u0026thinsp;50, Max\u0026thinsp;=\u0026thinsp;99) at baseline. Participants (N\u0026thinsp;=\u0026thinsp;86\u0026rsquo;676) resided in one of the 13 following countries: Austria, Belgium, Czech Republic, Denmark, France, Germany, Greece, Italy, Poland, Spain, Sweden, the Netherlands, and Switzerland. We selected these countries because they were the ones that participated consistently in the survey from the start and provided the most complete longitudinal data to investigate cognitive decline. As we focused on uncorrected hearing impairment, participants who reported that they had a hearing aid at any point during the study were excluded (\u003cem\u003eN\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5\u0026rsquo;311). The final sample consisted of 33\u0026rsquo;741 participants who had at least one observation in any of the variables used in the analysis (see Table A of Supplementary Material for a descriptives of study variables).\u003c/p\u003e \u003cp\u003e All participants provided a written informed consent before participating to the study. In accordance with the Declaration of Helsinki for research involving humans, SHARE was approved by the Ethics Council of the Max Planck Society and Ethics Research Committees in all participating countries.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eMeasures\u003c/h3\u003e\n\u003cp\u003eAll measures used in this study were assessed by interviewers with the use of CAPI (Computer-Assisted Personal Interviewing), ensuring standardization and reducing potential biases related to literacy levels of participants in different regions and cultures of Europe.\u003c/p\u003e \u003cp\u003eOutcomes: Three outcomes of cognitive functioning were assessed in every study wave and analysed: \u003cem\u003eimmediate recall\u003c/em\u003e, \u003cem\u003edelayed recall\u003c/em\u003e [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e] and \u003cem\u003everbal fluency\u003c/em\u003e [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. Immediate recall assessed the extent to which the participants were able to recall 10 words immediately after they were read out by the interviewer, within 1 minute. For delayed recall, participants were again asked to recall the same 10 words within a 1-minute timeframe, after having completed other parts of the interview (approximately 10 minutes later). For both recall tasks, a higher number of recalled words indicated better cognitive functioning. For verbal fluency, participants were asked to name as many animals as possible within 60 seconds. The same version of the question was asked in every wave, and the total score counted all animals named within the 60-seconds timeframe, regardless of whether they were real or mythical, a species or a specific breed of that species, the male or female or infant name. A higher number of animals indicated better verbal fluency.\u003c/p\u003e \u003cp\u003ePredictors: \u003cem\u003eControl variables\u003c/em\u003e assessed demographic information and chronic conditions. Chronological age, sex (0\u0026thinsp;=\u0026thinsp;males, 1\u0026thinsp;=\u0026thinsp;females), and educational level were measured at baseline. Educational level was calculated as a binary variable based on the median split of the categorical variable measuring education with the 1997 version of the International Standard Classification of Education [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e], with 0\u0026thinsp;=\u0026thinsp;low educational level and 1\u0026thinsp;=\u0026thinsp;high educational level.\u003c/p\u003e \u003cp\u003e \u003cem\u003eChronic conditions\u003c/em\u003e were assessed at each wave in the physical health module with the following question: \u0026ldquo;Some people suffer from chronic or long-term health problems. By chronic or long-term we mean it has troubled you over a period of time or is likely to affect you over a period of time. Do you have any such health problems, illness, disability or infirmity?\u0026rdquo;. If an individual reported a new condition, this information was added to their existing number of chronic conditions.\u003c/p\u003e \u003cp\u003e\u003cem\u003eHearing impairment\u003c/em\u003e was assessed in every wave. Participants had to indicate how their hearing was on a 5-point likert scale, ranging from 1\u0026thinsp;=\u0026thinsp;\u003cem\u003eExcellent\u003c/em\u003e to 5\u0026thinsp;=\u0026thinsp;\u003cem\u003ePoor\u003c/em\u003e. Higher scores indicated more severe subjective hearing impairment.\u003c/p\u003e \u003cp\u003eSocial Isolation was assessed with the social connectedness scale [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e] from wave 6. This was the first wave in which both social isolation and loneliness were concurrently measured. The social connectedness scale is a summary scale incorporating five social network characteristics into one composite score. The characteristics include: 1) network size (representing the number of individuals that the participant cited), 2) proximity (representing the number of cited individuals living within a 25 km range from the participant), 3) frequency of contact (representing the number of cited individuals with a least weekly contact to the participant), 4) support (representing the number of cited individuals with very or extremely close emotional ties), and, lastly, 5) diversity (representing the number of different types of relationships within the network). Network size, proximity, frequency of contact and support were assessed from 0 to 4 with 0\u0026thinsp;=\u0026thinsp;0 persons cited and 4\u0026thinsp;=\u0026thinsp;6\u0026ndash;7 persons cited. Diversity also ranged from 0 to 4, with 4 representing the highest diversity in the network comprising of all 4 possible categories (i.e., spouse, other family including children, friend, and other). The final scale ranged from 0\u0026thinsp;=\u0026thinsp;no social connectedness (0 social network members) to 4\u0026thinsp;=\u0026thinsp;high social connectedness. In order to create an indicator of social isolation, a binary variable was computed based on the social connectedness scale with 1 representing individuals with no social connections (scored 0 in social connectedness scale) and 0 representing individuals having scored 1 and above in the social connectedness scale.\u003c/p\u003e \u003cp\u003eLoneliness was assessed with the 3-item UCLA scale [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e] at wave 6. The mean composite score ranged from 3\u0026thinsp;=\u0026thinsp;\u003cem\u003enot lonely\u003c/em\u003e to 9\u0026thinsp;=\u0026thinsp;\u003cem\u003every lonely\u003c/em\u003e. Higher values indicated higher loneliness. A binary variable was computed based on the median value of the UCLA score with 0\u0026thinsp;=\u0026thinsp;\u003cem\u003elow loneliness\u003c/em\u003e (scored less than 4 in the UCLA) and 1\u0026thinsp;=\u0026thinsp;\u003cem\u003ehigh loneliness\u003c/em\u003e (scored equal or more than 4 in the UCLA).\u003c/p\u003e \u003cp\u003e \u003cem\u003eSocial Isolation x Loneliness profiles\u003c/em\u003e. Inspired by past research [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], we created four profiles based on the two binary indicators of social isolation and loneliness: 1) non-isolated and low loneliness, 2) non-isolated and high loneliness, 3) isolated and low loneliness, 4) isolated and high loneliness.\u003c/p\u003e\n\u003ch3\u003eAnalytical Strategy\u003c/h3\u003e\n\u003cp\u003eWe tested between-subjects\u0026rsquo; differences and within-subjects' change in immediate and delayed recall, as well as in verbal fluency, using multilevel modelling. To facilitate the interpretability of the results regarding the within subjects\u0026rsquo; change, we person-centred the time-varying variables (i.e., age, chronic conditions and hearing impairment). To investigate between-subjects differences of the time-varying variables we also calculated and included the across-waves person-mean in the models [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. Sex and educational level were measured in wave one and included in the model as time-invariant non-centred factors. Regarding hearing impairment, we were interested in the extent to which the linear and the quadratic change may relate to cognitive outcomes and therefore included a linear and a quadratic term.\u003c/p\u003e \u003cp\u003eWe present the final and most parsimonious models (i.e., the ones with the best fit) which tested fixed and random effects, as well as interaction terms (see below). Estimates are reported unstandardized. For the fixed effects, we reported 95% Confidence Intervals (CI) and \u003cem\u003ep\u003c/em\u003e values. The fit of the models was tested with Akaike\u0026rsquo;s Information Criterion (AIC), Bayesian Information Criterion (BIC) and \u0026minus;\u0026thinsp;2 log likelihood (-2LL) fit indices (see supplementary material). The Marginal R2 was used to assess the variance explained only by the fixed effects and the Conditional R2 was used to assess the variance explained by both the fixed and the random effects in each model. We included the different parameters in the model in a stepwise procedure: First, to verify the extent to which between-subjects differences and within-subjects change were related to the hierarchical clustering of the data, we tested a fully unconditional model, with no predictors included. Then, we added the fixed effects for all variables in the model, continuing with the inclusion of the random effects. The random effects included a random intercept and slope for the linear change and quadratic change of hearing impairment, allowing for individuals to have different baseline levels as well as different cognitive trajectories as a function of linear and quadratic change in hearing impairment. Finally, we tested the three interaction terms of interest one by one, namely the mean, change and squared change parameters of hearing impairment with the profiles of loneliness/social isolation. The final models presented have retained only the interaction effects that improved the model fit. All models were tested using Restricted Maximum Likelihood estimation method. All analyses were conducted with R [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e], and the \u003cem\u003elme4\u003c/em\u003e package [\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e].\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eCL and AI conceived the study; CL performed the statistical analysis and drafted the manuscript; SZ and NT helped draft the manuscript; EJ-B, MM, CS, GL, AR, MK and AI revised the manuscript. All authors have read and approved the final version of the manuscript and agree with the order of presentation of the authors.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis work was supported by the Swiss National Centre of Competence in Research LIVES \u0026ndash; Overcoming vulnerability: Life course perspectives, which is financed by the Swiss National Science Foundation (grant number: 51NF40-185901). The authors are grateful to the Swiss National Science Foundation for its financial assistance.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data is freely accessible. The data can be accessed through the SHARE project website \u0026ndash; www.share-project.org.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDeafness, N. I. \u0026amp; Disorders, O. C. Quick statistics about hearing. \u003cem\u003eStat. Epidemiol.\u003c/em\u003e (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLivingston, G. et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. \u003cem\u003elancet\u003c/em\u003e. \u003cb\u003e396\u003c/b\u003e, 413\u0026ndash;446 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFord, A. H. et al. 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Package \u0026lsquo;lme4\u0026rsquo;. \u003cem\u003econvergence\u003c/em\u003e 12, 2 (2015).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"cognitive abilities, hearing difficulties, psychosocial factors, old age","lastPublishedDoi":"10.21203/rs.3.rs-5174604/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5174604/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eHearing impairment affects a growing number of older adults and is associated with worse cognitive aging outcomes. However, the mechanisms linking hearing impairment and cognition are complex, and the role of potential moderating factors remains underexplored. This study examined whether social isolation and loneliness profiles (e.g., non-isolated but lonely) help explain why some older individuals experience faster cognitive decline as their hearing worsens, while others do not. Using longitudinal data from waves 1 to 9 of the Survey of Health, Ageing, and Retirement in Europe (SHARE), we analysed 33,741 individuals (Mage\u0026thinsp;=\u0026thinsp;61.4, SD\u0026thinsp;=\u0026thinsp;8.6). Multilevel modelling revealed that both levels and linear and quadratic changes in hearing impairment predicted lower cognitive performance and steeper cognitive decline. Additionally, compared to those who were non-isolated and less lonely, those in the non-isolated but lonelier profile exhibited steeper declines in episodic memory, but not executive functions, with worsening hearing. These findings highlight key psychosocial factors contributing to cognitive decline in the context of hearing impairment, underscoring the importance of targeted social and health interventions to support cognitive health in older adults.\u003c/p\u003e","manuscriptTitle":"Social isolation and loneliness moderate the association between uncorrected hearing impairment and cognitive aging across 18 years","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-26 18:53:27","doi":"10.21203/rs.3.rs-5174604/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"12003a88-5991-452a-b1a8-17d93600a88a","owner":[],"postedDate":"November 26th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":39934737,"name":"Biological sciences/Psychology"},{"id":39934738,"name":"Biological sciences/Psychology/Human behaviour"}],"tags":[],"updatedAt":"2024-12-16T05:08:51+00:00","versionOfRecord":[],"versionCreatedAt":"2024-11-26 18:53:27","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5174604","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5174604","identity":"rs-5174604","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}