Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis

Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis | bioRxiv /* */ /* */ <!-- <!-- /*! * yepnope1.5.4 * (c) WTFPL, GPLv2 */ (function(a,b,c){function d(a){return"[object Function]"==o.call(a)}function e(a){return"string"==typeof a}function f(){}function g(a){return!a||"loaded"==a||"complete"==a||"uninitialized"==a}function h(){var a=p.shift();q=1,a?a.t?m(function(){("c"==a.t?B.injectCss:B.injectJs)(a.s,0,a.a,a.x,a.e,1)},0):(a(),h()):q=0}function i(a,c,d,e,f,i,j){function k(b){if(!o&&g(l.readyState)&&(u.r=o=1,!q&&h(),l.onload=l.onreadystatechange=null,b)){"img"!=a&&m(function(){t.removeChild(l)},50);for(var d in y[c])y[c].hasOwnProperty(d)&&y[c][d].onload()}}var j=j||B.errorTimeout,l=b.createElement(a),o=0,r=0,u={t:d,s:c,e:f,a:i,x:j};1===y[c]&&(r=1,y[c]=[]),"object"==a?l.data=c:(l.src=c,l.type=a),l.width=l.height="0",l.onerror=l.onload=l.onreadystatechange=function(){k.call(this,r)},p.splice(e,0,u),"img"!=a&&(r||2===y[c]?(t.insertBefore(l,s?null:n),m(k,j)):y[c].push(l))}function j(a,b,c,d,f){return q=0,b=b||"j",e(a)?i("c"==b?v:u,a,b,this.i++,c,d,f):(p.splice(this.i++,0,a),1==p.length&&h()),this}function k(){var a=B;return a.loader={load:j,i:0},a}var l=b.documentElement,m=a.setTimeout,n=b.getElementsByTagName("script")[0],o={}.toString,p=[],q=0,r="MozAppearance"in l.style,s=r&&!!b.createRange().compareNode,t=s?l:n.parentNode,l=a.opera&&"[object Opera]"==o.call(a.opera),l=!!b.attachEvent&&!l,u=r?"object":l?"script":"img",v=l?"script":u,w=Array.isArray||function(a){return"[object Array]"==o.call(a)},x=[],y={},z={timeout:function(a,b){return b.length&&(a.timeout=b[0]),a}},A,B;B=function(a){function b(a){var a=a.split("!"),b=x.length,c=a.pop(),d=a.length,c={url:c,origUrl:c,prefixes:a},e,f,g;for(f=0;f<d;f++)g=a[f].split("="),(e=z[g.shift()])&&(c=e(c,g));for(f=0;f<b;f++)c=x[f](c);return c}function g(a,e,f,g,h){var i=b(a),j=i.autoCallback;i.url.split(".").pop().split("?").shift(),i.bypass||(e&&(e=d(e)?e:e[a]||e[g]||e[a.split("/").pop().split("?")[0]]),i.instead?i.instead(a,e,f,g,h):(y[i.url]?i.noexec=!0:y[i.url]=1,f.load(i.url,i.forceCSS||!i.forceJS&&"css"==i.url.split(".").pop().split("?").shift()?"c":c,i.noexec,i.attrs,i.timeout),(d(e)||d(j))&&f.load(function(){k(),e&&e(i.origUrl,h,g),j&&j(i.origUrl,h,g),y[i.url]=2})))}function h(a,b){function c(a,c){if(a){if(e(a))c||(j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}),g(a,j,b,0,h);else if(Object(a)===a)for(n in m=function(){var b=0,c;for(c in a)a.hasOwnProperty(c)&&b++;return b}(),a)a.hasOwnProperty(n)&&(!c&&!--m&&(d(j)?j=function(){var a=[].slice.call(arguments);k.apply(this,a),l()}:j[n]=function(a){return function(){var b=[].slice.call(arguments);a&&a.apply(this,b),l()}}(k[n])),g(a[n],j,b,n,h))}else!c&&l()}var h=!!a.test,i=a.load||a.both,j=a.callback||f,k=j,l=a.complete||f,m,n;c(h?a.yep:a.nope,!!i),i&&c(i)}var i,j,l=this.yepnope.loader;if(e(a))g(a,0,l,0);else if(w(a))for(i=0;i (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];var j=d.createElement(s);var dl=l!='dataLayer'?'&l='+l:'';j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;j.type='text/javascript';j.async=true;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-M677548'); Skip to main content Home About Submit ALERTS / RSS Search for this keyword Advanced Search New Results Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis View ORCID Profile Daniel J. McKeown , View ORCID Profile Douglas J. Angus , View ORCID Profile Ahmed A. Moustafa , View ORCID Profile Victor R. Schinazi doi: https://doi.org/10.1101/2025.05.15.654374 Daniel J. McKeown 1 OXYNAV Laboratory, School of Psychology, Faculty of Society and Design, Bond University , Gold Coast, Queensland, 4229, Australia Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Daniel J. McKeown For correspondence: dmckeown{at}bond.edu.au Douglas J. Angus 1 OXYNAV Laboratory, School of Psychology, Faculty of Society and Design, Bond University , Gold Coast, Queensland, 4229, Australia Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Douglas J. Angus Ahmed A. Moustafa 1 OXYNAV Laboratory, School of Psychology, Faculty of Society and Design, Bond University , Gold Coast, Queensland, 4229, Australia 2 Department of Human Anatomy and Physiology, the Faculty of Health Sciences, University of Johannesburg , South Africa 3 Centre for Data Analytics & School of Psychology, Bond University , Gold Coast, Queensland, Australia Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Ahmed A. Moustafa Victor R. Schinazi 1 OXYNAV Laboratory, School of Psychology, Faculty of Society and Design, Bond University , Gold Coast, Queensland, 4229, Australia 4 Future Health Technologies, Singapore-ETH Centre, Campus for Research Excellence and Technological Enterprise (CREATE) , Singapore Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Victor R. Schinazi Abstract Full Text Info/History Metrics Supplementary material Data/Code Preview PDF ABSTRACT This systematic and meta-analytical review examined how a reduction in oxygen availability to tissue (hypoxia) affects cognitive function. Hypoxia had a moderate-to-large detrimental effect on general cognitive ability and across domains, including memory, attention, executive function, processing speed, and psychomotor speed. Increased hypoxic severity was associated with greater declines in general cognitive ability and executive function, while longer duration of exposure was associated with greater declines in executive function and psychomotor speed. Participant age was a moderator for executive function and psychomotor speed, with older adults experiencing greater impairments. For executive function and psychomotor speed, the magnitude of these effects was less pronounced during intermittent and hypobaric exposures, potentially due to adaptive physiological mechanisms. While our models accounted for exposure characteristics and age of participants, substantial unexplained variance remained. These findings highlight hypoxia’s impact on cognition and emphasize the need to investigate underlying neurophysiological mechanisms that may influence individual vulnerability. INTRODUCTION Overcoming reductions in oxygen availability to tissue (hypoxia) is a demanding physiological challenge requiring nervous, respiratory, renal, and cardiovascular adaptation. One of the earliest real-world accounts of cognitive impairment in a high-altitude setting comes from meteorologist James Glaisher and co-pilot Henry Coxwell during their 1862 hot air balloon ascent to 11,000 m above sea level. As altitude increased, Coxwell recounts losing motor control of his hands, while Glaisher lost visual acuity and eventually consciousness. Interestingly, the occurrence of these symptoms of “balloon sickness” intensified progressively during ascent. While anecdotal, this account suggests that hypoxia induces cognitive impairments that may depend on the duration and severity of exposure. Despite advances in our understanding of physiological adaptations to hypoxia, the impact of hypoxia on cognition remains unclear, particularly in relation to exposure severity and duration. Cognition is a complex process, involving the integration of activity from multiple brain regions to interact and respond to a stimulus in the environment. Although valuable for understanding hypoxia’s impact on cognition, real-world assessments in high-altitude environments cannot fully control for changes in barometric pressure and temperature. Considering this, laboratory-based assessments involving the manipulation of oxygen concentrations of inspired air (fraction of inspired oxygen; F i O 2 ) allow for investigations of isolated hypoxic effects. In general, impairments in cognitive processes become evident from exposures equivalent to 2,500 to 3,000 m above sea level, but findings remain inconsistent, with hypoxia having a negligible-to-substantial impact on cognition [ 1 , 2 ]. This inconsistency in findings may be due to the lack of standardization of tasks to assess cognitive processes, with multiple tasks assessing a cognitive process but with differing performance outcomes. Variation in the age of participants, severity, duration, and type (e.g., normobaric, hypobaric, intermittent) of exposure as well as intrinsic brain activity (e.g., periodic and aperiodic components of electroencephalographic [EEG] activity) may also contribute to inconsistent findings [ 3 , 4 ]. Attentional tasks require the ability to sustain focus on a relevant stimulus while perceiving and appropriately ignoring irrelevant stimuli. Attention has been shown to be impaired in high-altitude exposures, with impairment increasing with the severity of exposure and attentional demand. Attentional performance is maintained at moderate altitudes (2,200 – 3,800 m above sea level) but reduced at extreme altitudes [5,800 m above sea level; 5, 6-8], in some cases persisting once returning to sea level [ 6 ]. Interestingly, attentional performance is more impacted by hypobaric exposures of hypoxia compared to normobaric exposures [ 8 ]. As attentional impairments are most evident during high-demand tasks [ 9 ], these findings suggest that attentional resources may be particularly vulnerable to hypoxia. Tasks requiring retention and learning, such as those assessing memory-specific processes, have demonstrated similar results. Here, impairments in learning and retention of memory tasks can occur in high altitude and persist once returning to sea level [1 - 2 weeks post-summit; 10]. Studies on memory processing in pilots also demonstrate that increasing hypoxic severity and task complexity are associated with greater performance decrements [ 11 , 12 ]. Alarmingly, individuals are mostly unaware of such impairments while actively engaged in the task. Reductions in memory performance coincide with selective reductions in blood flow and delivery in the posterior cerebral artery, which is a primary supplier of oxygen to the hippocampus [ 8 ]. This suggests that the hippocampus may play an important role as the locus of hypoxia-induced memory impairment. Complex tasks, such as performing two tasks simultaneously, place greater demands on executive functions to sustain goal-directed performance amid conflicting or distracting stimuli [ 13 , 14 ]. In hypoxia, severe exposures have been shown to severely impact executive functions [ 15 – 18 ]. For example, when exposed to 30 – 60 minutes of acute hypoxia, participants exhibit greater reductions in performance during the naming (incongruent) component compared to the reading (congruent) component of the Stroop task [ 16 – 18 ]. Interestingly, increases in the Stroop interference effect are associated with decreasing peripheral blood oxygen saturation [S p O 2 ; 18]. Task efficiency is also impacted by hypoxia and is related to the speed of processing and initiating a motor command [ 19 ], particularly when cognitive load is high [ 9 , 20 ]. Hypoxia’s impact on processing speed is also dependent on the type of stimulus being processed. Processing speed is reduced when presented with visual and auditory stimuli [ 9 , 20 , 21 ]. However, visual processing may be more impaired due to visual receptors inherently having a greater metabolic demand [ 22 , 23 ] and involving a more diverse neural network [ 24 ]. Considering this, the type of cognitive task is an important factor when considering hypoxia’s impact on speed of processing. Hypoxia also reduces an individual’s ability to execute motor commands in response to a stimulus [ 25 – 28 ]. This is not surprising since exposure to hypoxia has regularly shown to reduce motor cortical and spinal output [ 29 – 32 ]. Psychomotor performance is reduced with increased reaction time during perceptual-motor tasks [ 25 , 26 , 33 , 34 ]. However, this may be primarily due to reductions in processing speed [e.g., reduced visual sensitivity; 26, 33]. As human endeavours move into increasingly challenging environments, such as high altitude, a unique challenge is presented – how can complex cognitive processes operate with limited oxygen supply? Although 50 years of research [ 1 , 2 , 15 , 35 – 39 ] has documented the impact hypoxia has on individual cognitive processes, a comprehensive meta-analysis examining how factors such as severity, duration, type of exposure, participant age, and cognitive task type influence cognitive effects of hypoxia has not yet been conducted. In addition, previous systematic reviews have been limited by small study sizes [n = 7 - 18 included studies; 2, 35, 36], large variation in the time between onset of exposure and cognitive assessment [10 mins - 5 days; 35], the inclusion of concurrent exercise interventions [ 15 ], or a lack of meta-analytical approaches [ 1 , 2 , 36 – 39 ], all of which have hindered the standardization of hypoxic effects between studies [ 38 ]. Our systematic review and meta-analysis aims to provide a comprehensive synthesis of the impact hypoxia has on key cognitive domains including, memory, attention, executive function, processing speed, and psychomotor speed. In doing so, our review will: (1) provide an up-to-date assessment of the body of evidence, (2) address the question of how severity, duration, and type of exposure to hypoxia affects cognition compared to normal oxygen conditions in humans, and (3) what should be the focus of future research to better understand cognition in extreme environments. RESULTS Data Extraction The two authors DJM and VRS agreed on 98.95% of the data items ( n included= 38/857 data items, ĸ =.904) and disagreed on 1.05% (n= 9). From the disputed items, eight were ultimately included based on DJA’s decision. In total, 46 data items were identified as being suitable for inclusion with measures consisting of author, year of publication, study design, intervention, sample characteristics, hypoxic duration and severity, outcomes, and main findings pertaining to cognitive processes ( Table 1 ). View this table: View inline View popup Table 1. Characteristics of included data items (n = 46). Six data items were identified as having a substantial amount of risk of bias ( Table 2 ). This risk was predominantly from Domain 1 (bias due to confounding effects), where studies either included a concomitant exercise protocol, did not include a control comparison condition (i.e., normoxia/sea level or low-lander control), or had large participant age variability within the groups. Due to these potential risks of bias, these articles were not included in the meta-analyses. View this table: View inline View popup Download powerpoint Table 2. ROBINS-I-V2 risk of bias assessment for data items. A Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flow diagram provides a summary of the inclusion process ( Figure 1 ). A reference list of excluded data items is presented in Supplementary Material 1. Download figure Open in new tab Figure 1. PRISMA flow diagram detailing the systematic inclusion and exclusion of data items. A total of 858 items were identified during the initial phase. One article was removed as a duplicate. The 857 articles were then screened based on titles and abstracts with 811 being excluded. From the forty-six data items assessed for eligibility, six were excluded due to risk of bias consisting of (e.g., concomitant exercise protocol, lack of control/ normoxia condition, and no control/normoxia statistical comparisons). Ultimately, forty data items were included for meta-analyses. For the general cognitive ability and domain-specific models, significant coefficients are reported in text. For full model results including non-significant coefficients, see Supplementary Material 2. While funnel plots suggest the potential influence of publication bias in model results, the coefficients were similar between the random-effects and trimfill- corrected models (Supplementary Material 2). Considering this, the original random-effects and multivariate models are reported below. General Cognitive Ability A random-effects meta-analysis was conducted to examine the impact of hypoxia on general cognitive ability independent of moderators ( k = 151). The average effect size was moderate and negative ( b = -.44, 95% CI =-.55,-.33), and statistically significant ( z =-7.75, p <.0001; Figure 2 ) indicating that hypoxia has a moderate adverse effect on general cognitive ability independent of severity or duration of exposure and other moderators. Substantial heterogeneity was observed in effect sizes across studies ( I 2 = 78.72%, p <.0001, τ ² = 0.37, τ = 0.61, H 2 = 4.70), suggesting that factors beyond the primary study variables contributed to the variability in effect sizes. Download figure Open in new tab Download figure Open in new tab Figure 2. Forest plot for all 151 effect sizes with the grouped effect for the random-effects model categorising cognitive ability in hypoxia. The multivariate model ( k = 141) was a significant improvement over the reduced model (LRT = 40.70, p <.0001; full model: logLik =-172.28, AIC = 370.80, QE = 529.27; reduced model: logLik =-192.63, AIC = 389.34, QE = 661.83) indicating that the inclusion of the moderators explained more heterogeneity in the data, and a larger proportion of the variance (QM(7) = 29.19, p <.001). Regarding the effects of each moderator, the severity of hypoxia was associated with greater impairment in general cognitive ability ( b = 10.39, SE = 3.15, z = 3.30, p =.001, 95% CI = 4.22, 16.56).This result indicates that as the severity of hypoxia increases, so does the severity of impairment in general cognitive ability ( Figure 3 ). The psychomotor speed domain was also a significant moderator with hypoxic impairment seen in general cognitive ability ( b =-.48, SE =.12, z =-4.12, p <.0001, 95% CI =-.71,-.25), suggesting that psychomotor speed may be more adversely impacted by hypoxia compared to other cognitive domains. A moderate level of variance in effect sizes (σ² = 0.20, sqrt =.44) and a significant level of residual heterogeneity (QE(143) = 509.09, p <.0001) remained across studies, indicating that factors other than the included moderators contributed to the variance observed. Download figure Open in new tab Figure 3. Predicted cognitive ability decline in hypoxia as a function of severity. Attention A random-effects meta-analysis was conducted to examine the impact of hypoxia on attention ( k = 33). The average effect size was small and negative ( b =-.25, 95% CI =-.43,-.06), and statistically significant ( z =-2.61, p =.009; Figure 4 ) indicating that hypoxia has a small adverse effect on attention independent of severity or duration of exposure, and other moderators. Substantial heterogeneity was observed in effect sizes across studies ( I 2 = 67.27%, p <.0001, τ ² = 0.19, τ = 0.44, H 2 = 3.06), suggesting that factors beyond the primary study variables contributed to the variability in effect sizes. Download figure Open in new tab Download figure Open in new tab Download figure Open in new tab Download figure Open in new tab Download figure Open in new tab Figure 4. Forest plot for each cognitive domain for the random-effects model categorising hypoxia’s domain-specific impact. The inclusion of the multivariate model ( k = 33) was not a significant improvement over the reduced model (LRT = 7.61, p =.18; full model: logLik = - 23.28, AIC = 65.03, QE = 76.18; reduced model: logLik =-27.08, AIC = 58.56, QE = 98.19) indicating that the inclusion of the moderators did not explain more heterogeneity or a significant proportion of the variance in the data (QM(5) = 6.73, p =.24). A moderate level of variance in effect sizes (σ² = 0.14, sqrt =.37) and a significant level of residual heterogeneity (QE(27) = 76.18, p <.0001) remained across studies, indicating that factors other than the included moderators contributed to the variance observed. Memory A random-effects meta-analysis was conducted to examine the impact of hypoxia on the memory domain ( k = 44). The average effect size was moderate and negative ( b =-.33, 95% CI =-.54,-.13), and statistically significant ( z =-3.17, p =.002; Figure 4 ), indicating that hypoxia has a moderate adverse effect on memory independent of severity or duration of exposure, and other moderators. Substantial heterogeneity was observed in effect sizes across studies ( I 2 = 76.25%, p <.0001, τ ² = 0.35, τ = 0.59, H 2 = 4.21), suggesting that factors beyond the primary study variables contributed to the variability in effect sizes. The inclusion of the multivariate model ( k = 44) was a significant improvement over the reduced model (LRT = 38.79, p <.001; full model: logLik =-18.72, AIC = 88.86, QE = 57.45; reduced model: logLik =-38.11, AIC = 80.51, QE = 179.00) indicating that the inclusion of the moderators explained more heterogeneity and a significant proportion of the variance in the data (QM(14) = 30.16, p =.007). Regarding the effects of each moderator, tasks that rely on episodic memory were significant ( b =-2.54, SE =.93, z =-2.72, p =.007, 95% CI =-4.38,-.712), suggesting that episodic memory may be more adversely impacted by hypoxia compared to other memory tasks (e.g., working and associative memory). A moderate level of variance in effect sizes (σ² = 0.27, sqrt =.52) and a significant level of residual heterogeneity (QE(29) = 57.30, p =.001) remained across studies, indicating that factors other than the included moderators contributed to the variance observed. Executive Function A random-effects meta-analysis was conducted to examine the impact of hypoxia on the executive function domain ( k = 43). The average effect size was large and negative ( b =-.67, 95% CI =-.91,-.43), and statistically significant ( z =-5.45, p <.0001; Figure 4 ) indicating that hypoxia has a large adverse effect on executive function independently of severity or duration of exposure, and other moderators. Substantial heterogeneity was observed in effect sizes across studies ( I 2 = 84.64%, p <.0001, τ ² =.53, τ =.73, H 2 = 6.51), suggesting that factors beyond the primary study variables contributed to the variability in effect sizes. The inclusion of the multivariate model ( k =43) was a significant improvement over the reduced model (LRT = 109.26, p <.0001; full model: logLik =-8.55, AIC = 121.20, QE = 33.89; reduced model: logLik =-63.18, AIC = 130.66, QE = 236.87) indicating that the inclusion of the moderators explained more heterogeneity and a significant proportion of the variance in the data (QM(21) = 204.96, p <.0001). Regarding the effects of each moderator, the severity of hypoxia was associated with greater impairment in executive function ( b = 11.81, SE = 4.06, z = 2.91, p =.004, 95% CI = 3.86, 19.76; Figure 5 ), as well as longer durations of exposure ( b =-.18, SE =.09, z =-2.07, p =.038, 95% CI =-.35,-.01), especially in normobaric exposures ( b =-.57, SE =.29, z =-1.97, p =.048, 95% CI =-1.13,-.01). A range of executive function tasks were identified as being less impacted by hypoxia, including cognitive flexibility ( b = 1.88, p <.0001), decision making ( b = 1.81, p <.001), calculation error ( b = 3.13, p <.0001), map orientation ( b = 1.90, p <.0001), verbal fluency ( b = 2.69, p <.0001), non-verbal fluency ( b = 2.25, p <.001), proof reading ( b = 1.42, p =.041), reasoning ( b = 1.98, p <.0001), risk taking ( b = 1.79, p <.0001), and spatial tracking ( b = 1.45, p <.0001). Normobaric exposures of hypoxia had a greater impact on executive function compared to intermittent and hypobaric exposures ( b =-.57, SE =.29, z =-1.97, p =.048, 95% CI =-1.13,-.01). Participant age was also a significant moderator ( b =-.06, SE =.019, z =-2.86, p =.004, 95% CI =-.09,-.02), suggesting that hypoxia’s effect on executive function increases with participant age. The estimated between-study variance was negligible (σ² < 0.01), and residual heterogeneity was not statistically significant (QE(21) = 31.91, p =.06), suggesting that effect sizes were highly consistent across studies, though unexplored factors may still contribute to some remaining variability. Download figure Open in new tab Figure 5. Bubble plot visualising the 151 effect sizes across all domains in relation to the severity and duration of hypoxia exposure. Notably, as fraction of inspired oxygen decreases effect of hypoxia increases for most cognitive domains. Processing Speed A random-effects meta-analysis was conducted to examine the impact of hypoxia on the processing speed domain ( k = 18). The average effect size was moderate and negative ( b =-.30, 95% CI =-.54,-.05), and statistically significant ( z =-2.37, p =.018; Figure 4 ) indicating that hypoxia has a moderate adverse effect on processing speed independent of severity or duration of exposure, and other moderators. Substantial heterogeneity was observed in effect sizes across studies ( I 2 = 64.43%, p <.0001, τ ² = 0.17, τ = 0.42, H 2 = 2.81), suggesting that factors beyond the primary study variables contributed to the variability in effect sizes. The inclusion of the multivariate model ( k = 18) was a significant improvement over the reduced model (LRT = 112.24, p <.0001; full model: logLik =-12.87, AIC = 111.19, QE = 35.85; reduced model: logLik =-63.17, AIC = 129.65, QE = 243.87), indicating that the inclusion of the moderators did explain more heterogeneity in the data. However, the inclusion of the moderators did not explain a significant proportion of the variance (QM(6) = 0.62, p =.99). There was still a moderate level of variance in effect sizes across studies (σ² =.46, sqrt =.68), indicating that the other factors outside of the included moderators contribute to the variance seen in effect sizes. Psychomotor Speed A random-effects meta-analysis was conducted to examine the impact of hypoxia on the psychomotor domain ( k = 11). The average effect size was large and negative ( b = -.72, 95% CI =-1.10, -.33), and statistically significant ( z =-3.61, p <.001; Figure 4 ) indicating that hypoxia has a large negative effect on psychomotor speed independent of severity or duration of exposure, and other moderators. Substantial heterogeneity was observed in effect sizes across studies ( I 2 = 76.59%, p <.0001, τ ² = 0.31, τ = 0.56, H 2 = 4.27), suggesting that factors beyond the primary study variables contributed to the variability in effect sizes. The inclusion of the multivariate model ( k = 11) was not a significant improvement over the reduced model (LRT =.52, p =.97; full model: logLik =-8.13, AIC = 49.27, QE = 30.68; reduced model: logLik =-8.39, AIC = 22.29, QE = 45.86) indicating that the inclusion of the moderators did not explained more heterogeneity or a larger proportion of the variance in the data (QM(7) = 6.52, p =.48). Regarding the effects of each moderator, duration of hypoxia was associated with greater impairment in psychomotor speed ( b =-.17, SE =.07, z =-2.43, p =.015, 95% CI =-.30, -.03; Figure 5 ), indicating that the impact of hypoxia on psychomotor speed increases as the length of exposure increased. The type of hypoxic stimulus was also a significant moderator where effects were greater in hypobaric ( b =-5.99, SE = 2.67, z =-2.25, p =.025, 95% CI =-11.22, -.76) and normobaric hypoxia ( b =-8.51, SE = 3.79, z =-2.25, p =.025, 95% CI =-15.94, - 1.09) compared to intermittent hypoxia. Participant age was a significant moderator ( b =-.23, SE =.11, z =-2.02, p =.043, 95% CI =-.45, -.01), suggesting that hypoxia’s effect on psychomotor speed increases with participant age. A negligible level of variance in effect sizes across studies (σ² =.23, sqrt =.48) and a significant level of residual heterogeneity (QE(3) = 8.52, p =.036) remained, indicating that factors other than the included moderators contributed to the variance observed. DISCUSSION In this systematic and meta-analytical review, we provide robust evidence that hypoxia impairs general cognitive ability, alongside domain-specific functions including attention, memory, executive function, processing speed, and psychomotor speed. By including exposure severity, duration, type, participant age, and task characteristics, our models reveal that the impact of hypoxia on cognition is complex, not uniform, and dependent on the combination of moderating factors. Hypoxia impairs both general and domain-specific cognitive function We categorised general cognitive ability by pooling the performance of memory, attention, executive function, processing and psychomotor speed processes. We then constructed domains based on commonalities in cognitive tasks assessed in each study. Overall, hypoxia had a moderate negative effect on general cognitive ability, indicating that oxygen availability is integral for maintaining general cognitive function. However, not all cognitive domains had equal impairment. The psychomotor speed domain was more negatively impacted by hypoxia compared to other domains of the general cognitive ability model. This was also reflected in the domain-specific models, with psychomotor speed having the largest pooled negative effect of hypoxia. Psychomotor speed reflects the efficiency of the sensorimotor system and is typically characterised by the speed at which one can efficiently elicit a motor response to a perceptual stimulus, resulting in voluntary movement [ 40 ]. Reductions in psychomotor processes typically begin from mild severities of hypoxia, primarily due to motor speed and accuracy reductions [ 37 ]. At moderate-to-severe altitudes (∼4,000 m – 6,000 m above sea level), hypoxia has been shown to impair both perceptual and motor components of the sensorimotor system, including reduced integration of sensory information [ 21 , 41 ], decreased physiological tremor [ 42 ], diminished voluntary output from the motor cortex [ 31 , 43 ], and lowered excitability of both cortical and spinal motoneurons [ 29 , 30 , 44 ]. However, whether reductions in psychomotor performance is due to reductions in processing speed or reaction time to initiate a motor response remains unclear. Given that processing speed was negatively affected in our model, but H-reflex and M-wave latencies (known markers of spinal and peripheral nerve conduction) typically remain unchanged under hypoxic conditions [ 45 , 46 ], it is plausible that hypoxia has a stronger impact on speed of processing rather than speed of motor output. More complex cognitive domains were impaired by hypoxia, such as attention, memory, and executive function. However, not all tasks within these domains were impaired to the same extent. Of all cognitive domains, attention was the least affected by hypoxia, even in models accounting for various moderators. This effect may be due to the limited characteristics of tasks used to assess attention. Here, most tasks (e.g., Stroop, go-no-go, and flanker task) focus on response inhibition, which may reflect only one aspect of attention. In the memory domain, episodic memory was more impaired by hypoxia compared to working and associative memory. Episodic memory typically requires individuals to recall details about previous events such as recalling a set of words, events, or pictures [ 47 ]. Episodic memory has long been recognised to be dependent on the integrity of the hippocampus [ 48 , 49 ], with hippocampal lesion studies demonstrating impairments in episodic memory but not visual pattern matching or schematic spatial knowledge [ 50 – 52 ]. The hippocampus is known to be particularly susceptible to hypoxia due to its high metabolic activity and dense synaptic connectivity [ 53 – 58 ]. Here, investigations into the impact hypoxia has on animal models provide insight into the potential underlying mechanisms responsible for the decrements seen in hippocampal function when exposed to hypoxia. Specifically, when exposed to transient continuous oxygen deprivation, the CA3-CA1 synapses and NMDA receptors of CA1 neurons of the rodent’s hippocampus exhibit long-term potentiation indicative of pathological hyperexcitability [ 59 – 63 ], disruptions to modulatory neurotransmitter activity [e.g., reduced ACh production; 64, 65], and altered firing of excitatory and inhibitory neurons [ 66 ]. These intrinsic neuronal adaptations have a detrimental impact on key cognitive processes. Indeed, exposure to hypoxia is known to impair memory in mice when performing maze tasks [ 64 , 67 , 68 ] and passive avoidance tasks [ 69 ], which may recover after adaptation has occurred [ 70 ]. As episodic memory is reliant on CA1 and CA3 hippocampal neurons, it is unsurprising that memory, and particularly episodic memory, is susceptible to hypoxia-induced impairments. Executive function was also negatively impacted by hypoxia, but more pronounced in some tasks than others. This likely reflects the heterogeneous nature of the tasks used to assess executive functions. For example, verbal fluency tasks involve language-based processes while non-verbal fluency relies on visuospatial skills, both of which are categorised as executive functions. Therefore, accounting for heterogeneity in tasks may help explain some of the variance remaining in the moderator model. Executive function tasks are strongly reliant on prefrontal cortical activity, which is sensitive to hypoxia [ 71 ]. However, tasks that were less affected included cognitive flexibility, verbal and non-verbal fluency, decision making, reasoning, risk taking, and map orientation performance. These less effected tasks may rely on more distributed neural networks outside of the prefrontal cortex, such as the parietal and temporal cortices [ 13 , 14 , 72 ]. Considering this, performance preservation in these tasks may reflect compensation from other cortical regions (less of a dependence on prefrontal cortical activity), rather than the resilience of executive function. Type, severity, and duration modulate hypoxia’s impact on cognition The meta-analyses included studies performed in normobaric, hypobaric, and intermittent hypoxia. Variations in physiological adaptations across these types of exposure may account for some of the unexplained variance. For instance, when hypoxia is encountered in hypobaric environments, reductions in atmospheric pressure and temperature typically occur. This can alter respiratory, haematological, circulatory, and metabolic adaptations [ 73 ]. Similarly, intermittent exposure to hypoxia can produce a hormetic response [ 74 ]. This enhances pulmonary function, lowers blood pressure, mitigates inflammation, and increases cardiac vagal activity, leading to improved cognition, particularly in older populations [ 36 , 74 ]. Further consideration needs to be given to other environmental factors outside of isolated hypoxic effects that could contribute to alterations in cognitive performance. For example, cold stress can impact executive functioning and memory performance but is dependent on task complexity and attentional demand [ 2 ]. It is likely that adaptive processes that occur with hypobaric and intermittent exposures also mitigated hypoxia’s impact on some cognitive domains. Severity of hypoxia exposure was associated with lower performance in general cognitive ability and the executive function domain, whereby performance was reduced to a greater extent at more severe exposures. As physiological adaptations to hypoxia have an upper limit of mitigation [ 75 ], it is likely that at extreme altitudes impairment in cognitive function is unavoidable. However, as prolonged exposures to hypoxia result in more long-term adaptations [ 73 , 76 ], paradoxically, remaining at a moderate level of altitude over a prolonged duration may also lessen the impact of hypoxia on some cognitive processes. This may explain why duration of exposure was associated with worse performance in the executive function, and psychomotor domains but not the general cognitive ability, nor attention, memory, and processing speed domains. Why severity and duration moderator effects were seen in some domains but not others remains unclear. Limitations While a substantial amount of variance was explained by the inclusion of domain or task, participant age, and severity, duration, and type of hypoxia, a moderate amount of unexplained variance remained for all models. At the task level, previous reviews have identified the challenge of comparing between tasks to assess a common cognitive process [ 38 ]. We aimed to account for this variance by assessing standardised effects while controlling for the weighting of each effect across the studies included. It is well known that aging is associated with cognitive decline in a range of cognitive processes [ 77 , 78 ]. This was reflected in our meta-analyses as increasing participant age was associated with greater hypoxic impairment in executive function and psychomotor speed domains. Greater cognitive impairment in older individuals during hypoxia is likely due to reduced ability to effectively compensate for cognitive deficits, which are already associated with age-related cognitive decline [ 79 ]. For example, oxygen availability to active neural tissue is typically reduced by greater cerebrovascular resistance associated with aging, which reduces oxygen supply-demand and increases relative cognitive load [ 80 ]. Individual alpha peak frequency of the EEG is reflective of changes in cognitive load [ 81 ] and has been linked to variation in processing speed [ 81 ], memory [ 82 ], and attention [ 83 ]. Aperiodic activity, also referred to the level of ‘neural noise’ in the brain, has been linked to better cognitive performance in young and older populations [ 77 , 84 , 85 ]. Individuals who have greater exponents (reflective of reduced excitation:inhibition balance) and offsets (greater neural spiking) also exhibit better cognitive performance during processing speed [ 84 ], memory [ 86 – 88 ], and executive function [ 89 ] tasks. EEG research in hypoxia has, however, primarily focused on periodic activity [for review see 4]. Hypoxia has shown to left shift peak alpha frequency, indicated by a reduction in alpha power and an increase in theta power in canonical frequency bands [ 90 ] but see [ 91 ]. Hypobaric exposure to hypoxia reduces the exponent, reflective of a ‘noisier’ brain akin with non-pathological alterations in brain activity with age [ 3 ]. Considering this, future EEG research needs to focus on uncovering how hypoxia impacts aperiodic EEG activity and how this is associated with variation in hypoxia-induced reductions in cognitive performance. Conclusion We provide meta-analytical evidence that exposure to hypoxia has a moderate-to-large negative effect on general and domain-specific cognitive function. These effects are moderated by the severity or duration of exposure, depending on the cognitive task. Intermittent and hypobaric exposures of hypoxia may have a lower impact cognitive function due to protective adaptative physiological processes leading to increased hypoxia tolerability. Aging was associated with greater impairment in hypoxia in executive function and psychomotor speed. Although these findings align with the evidence of previous reviews indicating that hypoxia has a net negative effect on cognitive performance, a moderate level of unexplained variance remained due to moderating factors outside of those included in the meta-analysis. This variance may be explained by differences in underlying intrinsic brain activity that has previously been associated with performance differences in cognitive tasks. Considering this, future research should aim to uncover how these neural correlates change with hypoxic exposure. METHOD This systematic and meta-analytical review aligned with the 2020 PRISMA guidelines [ 92 ]. Eligibility Criteria Eligibility criteria conformed to the population, intervention, comparator, outcome, setting, types (PICOST) framework. Data items included all relevant randomised-controlled trials, observational studies, longitudinal studies, cohort studies, case-control studies, before-after studies, and cross-sectional studies or surveys involving healthy humans exposed to either environmental (high altitude) or simulated (laboratory-based) hypoxia. Studies were included if they used normal oxygen, sea-level conditions, or low-landers as a comparator and measured outcomes related to memory, attention, executive function, processing speed, or psychomotor speed. Data items with hypoxic exposure due to pathology (e.g., chronic obstructive pulmonary disease), with interventions that were pharmaceutical or exercise-based, which did not have suitable comparators, or conducted in a hospital-based setting, were excluded from the review. Data Sources & Search Strategy The Evidence Research Accelerator [TERA; 93] suite was used to aid in the data source and search strategy, and data screening and selection process. The SearchRefiner tool [ 94 ] of TERA was used to aid in data sourcing and developing the search strategy. A literature search querying SCOPUS, PubMed, Medline, and Cochrane Library from inception to 6 th January 2025 was performed. Search queries consisted of the terms “Hypoxia” or “Altitude”, or “Hypobaric”, and “Cognition” or “Attention” or “Memory” or “Executive Function” or “Processing Speed” or “Psychomotor Speed” with each of their combinations searched in each respective database. Thirteen seed PMIDs were used as “relevant citations” to aid in refining the literature search (Supplementary Material 1). In total, 858 data items were identified in the literature search. Using the Deduplicator tool [ 95 ] of TERA, one data item was identified as ‘likely being a duplicate’ and was removed [ 96 ], bringing the total number of data items to 857. Selection & Data Collection Process Authors DJM and VRS independently screened the citation search, title/abstract, full-texts, and trial registries for inclusion of data items against the inclusion and exclusion criteria. Any disagreements regarding data item inclusion were resolved by referring to the third author, DJA. Risk of Bias The ROBINS-I V2 assessment tool for non-randomised interventional studies was used to assess risk of bias within and between data items. Bias was assessed against seven domains: bias due to confounding (Domain 1), bias in the classification of interventions (Domain 2), bias in the selection of participants (Domain 3), bias due to deviation from intended intervention (Domain 4), bias due to missing data (Domain 5), bias arising from measurement of the outcome (Domain 6), bias in the selection of the reported result (Domain 7). For Domain 1, confounding factors consisted of participant-related, task-related, environment-related, and methodology-related factors ( Table 3 ). Risk of bias assessments were performed by authors DJM and VRS. Any discrepancies between studies were evaluated by the third author, DJA. A list of data items identified as being of moderate–severe risk during the risk of bias assessment is presented in Table 2 (n = 6). View this table: View inline View popup Download powerpoint Table 3. List of confounding factors taken into consideration of data items assessed against Domain 1 of the ROBINS-I V2. Meta-analysis Meta-analyses were performed in R (v 4.3.1) using the metafor package (v 4.8-0). A general cognitive ability construct was created, including all cognitive tasks, measured in the data items. Cognitive domain constructs for attention, memory, executive function, processing speed, and psychomotor speed were created from data items categorized in specified cognitive tasks ( Table 4 ). View this table: View inline View popup Download powerpoint Table 4. List of each cognitive domain construct and the associated cognitive tasks. Firstly, for the general cognitive ability and individual cognitive domains, a reduced model was calculated, which consisted of including study ID as a random-effect without including moderators. Following this, a full model was calculated by performing a multivariate mixed-effects model, which included moderators. Previous literature suggests that the impact of hypoxia on cognition may be dependent on the severity (F i O 2 level) and duration (minutes of exposure) of the hypoxic stimulus. Accordingly, severity and duration of hypoxia were included as moderators in the multivariate model. For studies comparing highlanders to lowlanders, we treated the highlanders’ exposure duration as chronic and used the mean age of participants (in minutes) as a proxy for duration. Due to large variability in duration of exposure and skewness between studies, duration of exposure was log-transformed. Additionally, the type (normobaric hypoxia, hypoxia in barometric pressure equivalent to sea level; hypobaric hypoxia, hypoxia in barometric pressure lower than sea level; intermittent hypoxia, cyclic exposures to normobaric hypoxia typically in one minute intervals) of stimulus, cognitive domain for the cognitive ability model, cognitive task for the individual domain models, and participant age, were added as additional moderators to identify if the effects of hypoxia are type-, domain/task-, and age-specific. The reduced and full models were compared against each other using an ANOVA. In both models, Hedge’s g (standardised mean difference) was calculated to quantify the effect size of each cognitive outcome measure, and 95% confidence intervals were used for variance in effect size. Forest plots were used to visualise the relationships between effect sizes and the overall random effect. Funnel plots were used to inspect publication bias ( Figure 6 and Supplementary Material 2). The trimfill function of the metafor R package was used to correct effect sizes for potential confounding of publication bias (Supplementary Material 2). Positive Hedge’s g scores indicate better cognitive performance in hypoxic conditions, while negative Hedge’s g scores indicate worse cognitive performance in hypoxic conditions. To visualise the relationship between hypoxia severity and cognitive ability decline, a meta-regression based on the multivariate mixed effects model was fit to a predicted dataset where severity was varied across its observed range derived from the 152 effect sizes. The duration of exposure and participant age were held constant as the average means in the general cognitive ability model (duration = 11 hours, participant age = 30 years). Download figure Open in new tab Figure 6. Funnel plot visualising the distribution of effect sizes included in the reduced model of the General Cognitive Ability Domain. DATA AVAILABILITY Collated data and analysis code used in this manuscript can be found at https://github.com/MindSpaceLab/Hypoxia_Cognition_Review COMPETING INTERESTS AND FUNDING The authors declare that no competing interests exist, and no funding was obtained for this work. AUTHOR CONTRIBUTIONS Conceptualization: D.J.M., D.J.A, and V.R.S.; Data curation: D.J.M., D.J.A, and V.R.S.; Formal analysis: D.J.M., D.J.A, A.A.M., and V.R.S; Project administration: D.J.M.; Visualization: D.J.M.; Writing - original draft: D.J.M., D.J.A, A.A.M., and V.R.S.; Writing - review & editing: D.J.M., D.J.A, A.A.M., and V.R.S. Footnotes Correction to Figure 4 which was missing figure panels for Attention and Executive Function domain. https://github.com/MindSpaceLab/Hypoxia_Cognition_Review REFERENCES 1. ↵ Martin , K. , et al. , The Impact of Environmental Stress on Cognitive Performance: A Systematic Review . Human Factors , 2019 . 61 ( 8 ): p. 1205 – 1246 . OpenUrl CrossRef PubMed 2. ↵ Taylor , L. , et al. , The Impact of Different Environmental Conditions on Cognitive Function: A Focused Review . Front Physiol , 2015 . 6 : p. 372 . OpenUrl PubMed 3. ↵ Coronel-Oliveros , C. , et al. , Elevating Understanding: Linking High-Altitude Hypoxia to Brain Aging Through EEG Functional Connectivity and Spectral Analyses . Network Neuroscience , 2023 : p. 1 – 39 . 4. ↵ Otto , S.R. , et al. , EEG as a neural measure of hypoxia-related impairment . Frontiers in Cognition , 2025 . Volume 4 - 2025. 5. Limmer , M. and P. Platen , The influence of hypoxia and prolonged exercise on attentional performance at high and extreme altitudes: A pilot study . PLoS One , 2018 . 13 ( 10 ): p. e0205285 . OpenUrl CrossRef PubMed 6. ↵ Bonnon , M. , M.C. Noel-Jorand , and P. Therme , Effects of different stay durations on attentional performance during two mountain expeditions . Aviat Space Environ Med , 2000 . 71 ( 7 ): p. 678 – 84 . OpenUrl PubMed 7. Ando , S. , Y. Yamada , and M. Kokubu , Reaction time to peripheral visual stimuli during exercise under hypoxia . J Appl Physiol ( 1985 ), 2010. 108 ( 5 ): p. 1210-6. 8. ↵ Ando , S. , et al. , Acute hypoxia impairs posterior cerebral bioenergetics and memory in man . Exp Physiol , 2023 . 108 ( 12 ): p. 1516 – 1530 . OpenUrl CrossRef PubMed 9. ↵ Wang , Y. , et al. , Long-Term Exposure to High Altitude Affects Voluntary Spatial Attention at Early and Late Processing Stages . Scientific Reports , 2014 . 4 ( 1 ): p. 4443 . OpenUrl CrossRef 10. Kramer , A.F. , J.T. Coyne , and D.L. Strayer , Cognitive function at high altitude . Hum Factors , 1993 . 35 ( 2 ): p. 329 – 44 . OpenUrl CrossRef PubMed 11. ↵ Asmaro , D. , J. Mayall , and S. Ferguson , Cognition at altitude: impairment in executive and memory processes under hypoxic conditions . Aviat Space Environ Med , 2013 . 84 ( 11 ): p. 1159 – 65 . OpenUrl CrossRef PubMed Web of Science 12. ↵ Malle , C. , et al. , Working memory impairment in pilots exposed to acute hypobaric hypoxia . Aviat Space Environ Med , 2013 . 84 ( 8 ): p. 773 – 9 . OpenUrl CrossRef 13. ↵ Szameitat , A.J. , et al. , Localization of executive functions in dual-task performance with fMRI . Journal of Cognitive Neuroscience , 2002 . 14 ( 8 ): p. 1184 – 99 . OpenUrl CrossRef PubMed Web of Science 14. ↵ Ghanavati , E. , et al. , Differential role of prefrontal, temporal and parietal cortices in verbal and figural fluency: Implications for the supramodal contribution of executive functions . Scientific Reports , 2019 . 9 ( 1 ): p. 3700 . OpenUrl CrossRef PubMed 15. ↵ Ando , S. , et al. , The interactive effects of acute exercise and hypoxia on cognitive performance: A narrative review . Scandinavian Journal of Medicine & Science in Sports , 2020 . 30 ( 3 ): p. 384 – 398 . OpenUrl CrossRef PubMed 16. ↵ Ochi , G. , et al. , Neural basis for reduced executive performance with hypoxic exercise . Neuroimage , 2018 . 171 : p. 75 – 83 . OpenUrl CrossRef PubMed 17. Chroboczek , M. , et al. , Acute Normobaric Hypoxia Lowers Executive Functions among Young Men despite Increase of BDNF Concentration . International Journal of Environmental Research and Public Health , 2022 . 19 ( 17 ): p. 10802 . OpenUrl CrossRef 18. ↵ Ochi , G. , et al. , Hypoxia-induced lowered executive function depends on arterial oxygen desaturation . The Journal of Physiological Sciences , 2018 . 68 ( 6 ): p. 847 – 853 . OpenUrl CrossRef PubMed 19. ↵ Silva-Fernandes , A. , et al. , Processing speed mediates the association between physical activity and executive functioning in elderly adults . Front Psychol , 2022 . 13 : p. 958535 . OpenUrl CrossRef PubMed 20. ↵ Seech , T.R. , et al. , Impaired Sensory Processing During Low-Oxygen Exposure: A Noninvasive Approach to Detecting Changes in Cognitive States . Front Psychiatry , 2020 . 11 : p. 12 . OpenUrl PubMed 21. ↵ Blacker , K.J. and D.G. McHail , Effects of Acute Hypoxia on Early Visual and Auditory Evoked Potentials . Front Neurosci , 2022 . 16 : p. 846001 . OpenUrl CrossRef PubMed 22. ↵ Barbur , J.L. and D.M. and Connolly , Effects of hypoxia on color vision with emphasis on the mesopic range . Expert Review of Ophthalmology , 2011 . 6 ( 4 ): p. 409 – 420 . OpenUrl CrossRef 23. ↵ Wong-Riley , M.T ., Energy metabolism of the visual system . Eye Brain , 2010 . 2 : p. 99 – 116 . OpenUrl CrossRef PubMed 24. ↵ Kumar , U. , et al. , Mapping the unique neural engagement in deaf individuals during picture, word, and sign language processing: fMRI study . Brain Imaging and Behavior , 2024 . 18 ( 4 ): p. 835 – 851 . OpenUrl CrossRef 25. ↵ Bloomfield , P.M. , et al. , Carbon dioxide protects simulated driving performance during severe hypoxia . Eur J Appl Physiol , 2023 . 123 ( 7 ): p. 1583 – 1593 . OpenUrl CrossRef PubMed 26. ↵ Fowler , B. , et al. , The threshold for hypoxia effects on perceptual-motor performance . Hum Factors , 1987 . 29 ( 1 ): p. 61 – 6 . OpenUrl CrossRef PubMed 27. Davis , J.E. , et al. , Cognitive and psychomotor responses to high-altitude exposure in sea level and high-altitude residents of Ecuador . J Physiol Anthropol , 2015 . 34 ( 1 ): p. 2 . OpenUrl CrossRef PubMed 28. ↵ Bouquet , C.A. , et al. , Psychomotor skills learning under chronic hypoxia . Neuroreport , 1999 . 10 ( 14 ): p. 3093 – 9 . OpenUrl CrossRef PubMed Web of Science 29. ↵ McKeown , D.J. , M.J. Simmonds , and J.J. Kavanagh , Reduced blood oxygen levels induce changes in low-threshold motor unit firing that align with the individual’s tolerance to hypoxia . J Neurophysiol , 2019 . 121 ( 5 ): p. 1664 – 1671 . OpenUrl CrossRef PubMed 30. ↵ McKeown , D.J. , G.M. Stewart , and J.J. Kavanagh , The severity of acute hypoxaemia determines distinct changes in intracortical and spinal neural circuits . Exp Physiol , 2023 . 31. ↵ McKeown , D.J. , et al. , Severe acute hypoxia impairs recovery of voluntary muscle activation after sustained submaximal elbow flexion . J Physiol , 2021 . 32. ↵ Goodall , S. , E.Z. Ross , and L.M. Romer , Effect of graded hypoxia on supraspinal contributions to fatigue with unilateral knee-extensor contractions . J Appl Physiol ( 1985 ), 2010. 109 ( 6 ): p. 1842-51. 33. ↵ Fowler , B. , M. Taylor , and G. Porlier , The effects of hypoxia on reaction time and movement time components of a perceptual-motor task . Ergonomics , 1987 . 30 ( 10 ): p. 1475 – 85 . OpenUrl CrossRef PubMed 34. ↵ Pun , M. , et al. , Effect of Acute, Subacute, and Repeated Exposure to High Altitude ( 5050 m ) on Psychomotor Vigilance . Front Physiol , 2018 . 9 : p. 677 . OpenUrl CrossRef PubMed 35. ↵ McMorris , T. , et al. , Effect of acute hypoxia on cognition: A systematic review and meta-regression analysis . Neurosci Biobehav Rev , 2017 . 74 (Pt A ): p. 225 – 232 . OpenUrl CrossRef PubMed 36. ↵ Boulares , A. , et al. , Effects of Intermittent Hypoxia Protocols on Cognitive Performance and Brain Health in Older Adults Across Cognitive States: A Systematic Literature Review . J Alzheimers Dis , 2024 . 101 ( 1 ): p. 13 – 30 . OpenUrl CrossRef PubMed 37. ↵ Virués-Ortega , J. , et al. , Neuropsychological Functioning Associated with High-Altitude Exposure . Neuropsychology Review , 2004 . 14 ( 4 ): p. 197 – 224 . OpenUrl CrossRef PubMed 38. ↵ Post , T.E. , et al. , Sensitivity of cognitive function tests to acute hypoxia in healthy subjects: a systematic literature review . Frontiers in Physiology , 2023 . 14 . 39. ↵ Aboouf , M.A. , et al. , The Brain at High Altitude: From Molecular Signaling to Cognitive Performance . Int J Mol Sci , 2023 . 24 ( 12 ). 40. ↵ Craighero , L ., The Role of the Sensorimotor System in Cognitive Functions . Brain Sci , 2022 . 12 ( 5 ). 41. ↵ Blacker , K.J. , et al. , Deficits in Visual Processing During Hypoxia as Evidenced by Visual Mismatch Negativity . Aerospace Medicine and Human Performance , 2021 . 92 ( 5 ): p. 326 – 332 . OpenUrl CrossRef 42. ↵ Krause , W.L. , et al. , Acute hypoxia activates human 8–12 Hz physiological tremor . Respiration Physiology , 2000 . 123 ( 1 ): p. 131 – 141 . OpenUrl CrossRef PubMed 43. ↵ Goodall , S. , et al. , Supraspinal fatigue after normoxic and hypoxic exercise in humans . J Physiol , 2012 . 590 ( 11 ): p. 2767 – 82 . OpenUrl CrossRef PubMed 44. ↵ Goodall , S. , G. Howatson , and K. Thomas , Modulation of specific inhibitory networks in fatigued locomotor muscles of healthy males . Exp Brain Res , 2018 . 236 ( 2 ): p. 463 – 473 . OpenUrl CrossRef PubMed 45. ↵ Kayser , B. , R. Bökenkamp , and T. Binzoni , Alpha-motoneuron excitability at high altitude . European journal of applied physiology and occupational physiology , 1993 . 66 : p. 1 – 4 . OpenUrl CrossRef PubMed Web of Science 46. ↵ Willer , J.C. , G. Miserocchi , and H. Gautier , Hypoxia and monosynaptic reflexes in humans . Journal of Applied Physiology , 1987 . 63 ( 2 ): p. 639 – 645 . OpenUrl CrossRef PubMed Web of Science 47. ↵ Mayer , V. and A.J. Yates , Intellectual changes following temporal lobectomy for psychomotor epilepsy; preliminary communication . J Neurol Neurosurg Psychiatry , 1955 . 18 ( 1 ): p. 44 – 52 . OpenUrl FREE Full Text 48. ↵ Mayes , A.R. and N. Roberts , Theories of episodic memory . Philos Trans R Soc Lond B Biol Sci , 2001 . 356 ( 1413 ): p. 1395-408. 49. ↵ Ekstrom , A.D. and C. Ranganath , Space, time, and episodic memory: The hippocampus is all over the cognitive map . Hippocampus , 2018 . 28 ( 9 ): p. 680 – 687 . OpenUrl CrossRef PubMed 50. ↵ Spiers , H.J. , et al. , Bilateral hippocampal pathology impairs topographical and episodic memory but not visual pattern matching . Hippocampus , 2001 . 11 ( 6 ): p. 715 – 25 . OpenUrl CrossRef PubMed Web of Science 51. Rosenbaum , R.S. , et al. , Remote spatial memory in an amnesic person with extensive bilateral hippocampal lesions . Nature Neuroscience , 2000 . 3 ( 10 ): p. 1044 – 1048 . OpenUrl CrossRef PubMed Web of Science 52. ↵ Bird , C.M. and N. Burgess , The hippocampus and memory: insights from spatial processing . Nature Reviews Neuroscience , 2008 . 9 ( 3 ): p. 182 – 194 . OpenUrl CrossRef PubMed Web of Science 53. ↵ Vetrovoy , O. , et al. , Prenatal Hypoxia Induces Premature Aging Accompanied by Impaired Function of the Glutamatergic System in Rat Hippocampus . Neurochem Res , 2021 . 46 ( 3 ): p. 550 – 563 . OpenUrl CrossRef PubMed 54. Zhang , X.Y. , et al. , Crocin attenuates acute hypobaric hypoxia-induced cognitive deficits of rats . Eur J Pharmacol , 2018 . 818 : p. 300 – 305 . OpenUrl CrossRef PubMed 55. Zhu , M. , et al. , Effect of acute exposure to hypobaric hypoxia on learning and memory in adult Sprague-Dawley rats . Behav Brain Res , 2019 . 367 : p. 82 – 90 . OpenUrl CrossRef PubMed 56. Shushanyan , R. , et al. , Histological and cytochemical analysis of the brain under conditions of hypobaric hypoxia-induced oxygen deficiency in albino rats . Acta Histochem , 2023 . 125 ( 8 ): p. 152114 . OpenUrl CrossRef PubMed 57. Lu , G. , G. Rili , and M. Shuang , Impact of hypoxia on the hippocampus: A review . Medicine (Baltimore ), 2025 . 104 ( 12 ): p. e41479 . OpenUrl CrossRef PubMed 58. ↵ Biswal , S. , et al. , Global hypoxia induced impairment in learning and spatial memory is associated with precocious hippocampal aging . Neurobiology of Learning and Memory , 2016 . 133 : p. 157 – 170 . OpenUrl CrossRef PubMed 59. ↵ Ai , J. and A. Baker , Long-term potentiation of evoked presynaptic response at CA3– CA1 synapses by transient oxygen-glucose deprivation in rat brain slices . Experimental Brain Research , 2006 . 169 ( 1 ): p. 126 – 129 . OpenUrl CrossRef PubMed Web of Science 60. Crepel , V. , et al. , Anoxia-induced LTP of isolated NMDA receptor-mediated synaptic responses . Journal of Neurophysiology , 1993 . 69 ( 5 ): p. 1774 – 1778 . OpenUrl CrossRef PubMed Web of Science 61. Quintana , P. , et al. , Acid-sensing ion channel 1a drives AMPA receptor plasticity following ischaemia and acidosis in hippocampal CA1 neurons . J Physiol , 2015 . 593 ( 19 ): p. 4373 – 86 . OpenUrl CrossRef PubMed 62. Kumral , A. , et al. , Erythropoietin improves long-term spatial memory deficits and brain injury following neonatal hypoxia-ischemia in rats . Behav Brain Res , 2004 . 153 ( 1 ): p. 77 – 86 . OpenUrl CrossRef PubMed Web of Science 63. ↵ Ji , W. , et al. , NMDA Receptor-Mediated Excitotoxicity Is Involved in Neuronal Apoptosis and Cognitive Impairment Induced by Chronic Hypobaric Hypoxia Exposure at High Altitude . High Alt Med Biol , 2021 . 22 ( 1 ): p. 45 – 57 . OpenUrl CrossRef PubMed 64. ↵ Bekker , A. , et al. , Isoflurane preserves spatial working memory in adult mice after moderate hypoxia . Anesth Analg , 2006 . 102 ( 4 ): p. 1134 – 8 . OpenUrl CrossRef PubMed Web of Science 65. Gibson , G.E. and T.E. Duffy , Impaired synthesis of acetylcholine by mild hypoxic hypoxia or nitrous oxide . J Neurochem , 1981 . 36 ( 1 ): p. 28 – 33 . OpenUrl CrossRef PubMed Web of Science 66. ↵ Hencz , A. , et al. , Mild hypoxia-induced structural and functional changes of the hippocampal network . Front Cell Neurosci , 2023 . 17 : p. 1277375 . OpenUrl CrossRef PubMed 67. ↵ McCullough , M.L ., The behavioral effects of prenatal hypoxia in the rat . Dev Psychobiol , 1976 . 9 ( 4 ): p. 335 – 42 . OpenUrl CrossRef PubMed 68. ↵ Sun , M.K. , H. Xu , and D.L. Alkon , Pharmacological protection of synaptic function, spatial learning, and memory from transient hypoxia in rats . J Pharmacol Exp Ther , 2002 . 300 ( 2 ): p. 408 – 16 . OpenUrl Abstract / FREE Full Text 69. ↵ Lin , H. , et al. , Attenuating brain edema, hippocampal oxidative stress, and cognitive dysfunction in rats using hyperbaric oxygen preconditioning during simulated high-altitude exposure . J Trauma Acute Care Surg , 2012 . 72 ( 5 ): p. 1220 – 7 . OpenUrl CrossRef PubMed 70. ↵ Shao , G. , et al. , Hypoxic Preconditioning Improves Spatial Cognitive Ability in Mice . Neurosignals , 2008 . 15 ( 6 ): p. 314 – 321 . OpenUrl 71. ↵ Zani , A. , Y. Dishi , and A.M. Proverbio , From oxygen shortage to neurocognitive challenges: behavioral patterns and imaging insights . Frontiers in Cognition , 2024 . Volume 3 - 2024. 72. ↵ Iaria , G. , et al. , Retrosplenial and hippocampal brain regions in human navigation: complementary functional contributions to the formation and use of cognitive maps . European Journal of Neuroscience , 2007 . 25 ( 3 ): p. 890 – 899 . OpenUrl CrossRef PubMed Web of Science 73. ↵ Hoiland , R.L. , et al. , Ventilatory and cerebrovascular regulation and integration at high-altitude . Clin Auton Res , 2018 . 28 ( 4 ): p. 423 – 435 . OpenUrl CrossRef PubMed 74. ↵ Lee , D. , et al. , Prefrontal executive function enhanced by prior acute inhalation of low-dose hypoxic gas: Modulation via cardiac vagal activity . Neuroimage , 2025 . 310 : p. 121139 . OpenUrl CrossRef PubMed 75. ↵ West , J.B ., High-Altitude Medicine . American Journal of Respiratory and Critical Care Medicine , 2012 . 186 ( 12 ): p. 1229 – 1237 . OpenUrl CrossRef PubMed Web of Science 76. ↵ Caldwell , H.G. , et al. , Stability in neurovascular function at 3800m . Physiol Behav , 2017 . 182 : p. 62 – 68 . OpenUrl CrossRef PubMed 77. ↵ Finley , A.J. , et al. , Resting EEG Periodic and Aperiodic Components Predict Cognitive Decline Over 10 Years . The Journal of Neuroscience , 2024 . 44 ( 13 ): p. e1332232024 . OpenUrl Abstract / FREE Full Text 78. ↵ Salthouse , T.A ., Shared and unique influences on age-related cognitive change . Neuropsychology , 2017 . 31 ( 1 ): p. 11 – 19 . OpenUrl CrossRef PubMed 79. ↵ Snyder , B. , et al. , Cerebral Hypoxia: Its Role in Age-Related Chronic and Acute Cognitive Dysfunction . Anesth Analg , 2021 . 132 ( 6 ): p. 1502 – 1513 . OpenUrl CrossRef PubMed 80. ↵ McKetton , L. , et al. , Cerebrovascular Resistance in Healthy Aging and Mild Cognitive Impairment . Front Aging Neurosci , 2019 . 11 : p. 79 . OpenUrl CrossRef PubMed 81. ↵ Haegens , S. , et al. , Inter-and intra-individual variability in alpha peak frequency . Neuroimage , 2014 . 92 ( 100 ): p. 46 – 55 . OpenUrl CrossRef PubMed Web of Science 82. ↵ Angelakis , E. , et al. , Peak alpha frequency: an electroencephalographic measure of cognitive preparedness . Clin Neurophysiol , 2004 . 115 ( 4 ): p. 887 – 97 . OpenUrl CrossRef PubMed 83. ↵ Campbell , A.J. , et al. , Resting-state EEG correlates of sustained attention in healthy ageing: Cross-sectional findings from the LEISURE study . Neurobiol Aging , 2024 . 144 : p. 68 – 77 . OpenUrl CrossRef PubMed 84. ↵ Ouyang , G. , et al. , Decomposing alpha and 1/f brain activities reveals their differential associations with cognitive processing speed . Neuroimage , 2020 . 205 : p. 116304 . OpenUrl CrossRef PubMed 85. ↵ McKeown , D.J. , et al. , Lower aperiodic EEG activity is associated with reduced verbal fluency performance across adulthood . Neurobiology of Aging , 2025 . 151 : p. 29 – 41 . OpenUrl CrossRef PubMed 86. ↵ Virtue-Griffiths , S. , et al. , Task-related changes in aperiodic activity are related to visual working memory capacity independent of event-related potentials and alpha oscillations . bioRxiv , 2022 : p. 2022.01.18.476852. 87. Preston , M. , N. Schaworonkow , and B. Voytek , Oscillations and aperiodic activity: Evidence for dynamic changes in both during memory encoding . bioRxiv , 2022 : p. 2022.10.04.509632. 88. ↵ Preston , M. , Jr. , N. Schaworonkow , and B. Voytek , Time-resolved aperiodic and oscillatory dynamics during human visual memory encoding . J Neurosci , 2025 . 89. ↵ Dave , S. , et al. , Electrophysiological evidence for preserved primacy of lexical prediction in aging . Neuropsychologia , 2018 . 117 : p. 135 – 147 . OpenUrl CrossRef PubMed 90. ↵ Ozaki , H. , S. Watanabe , and H. Suzuki , Topographic EEG changes due to hypobaric hypoxia at simulated high altitude . Electroencephalogr Clin Neurophysiol , 1995 . 94 ( 5 ): p. 349 – 56 . OpenUrl CrossRef PubMed 91. ↵ Zhao , J.P. , et al. , Characteristics of EEG activity during high altitude hypoxia and lowland reoxygenation . Brain Res , 2016 . 1648(Pt A ): p. 243 – 249 . 92. ↵ Page , M.J. , et al. , The PRISMA 2020 statement: an updated guideline for reporting systematic reviews . BMJ , 2021 . 372 : p. n71. 93. Clark , J. , et al. , A full systematic review was completed in 2 weeks using automation tools: a case study . J Clin Epidemiol , 2020 . 121 : p. 81 – 90 . OpenUrl CrossRef PubMed 94. ↵ Scells , H . and G. Zuccon , searchrefiner: A Query Visualisation and Understanding Tool for Systematic Reviews , in 27th ACM International Conference on Information and Knowledge Management . 2018 , ACM: Torino, Italy . p. 1939 - 1942. 95. ↵ Forbes , C. , et al. , Automation of duplicate record detection for systematic reviews: Deduplicator . Systematic Reviews , 2024 . 13 ( 1 ): p. 206 . OpenUrl CrossRef PubMed 96. ↵ Dopwell , F. , et al. , “More than meets the eye”: when the neonatal course may impact several years out . J Dev Behav Pediatr , 2014 . 35 ( 7 ): p. 467 – 9 . OpenUrl PubMed 97. Aebi , M.R. , et al. , Cognitive Impairment During Combined Normobaric vs . Hypobaric and Normoxic vs. Hypoxic Acute Exposure. Aerosp Med Hum Perform , 2020 . 91 ( 11 ): p. 845 – 851 . OpenUrl PubMed 98. Bailey , D.M. , et al. , Exaggerated systemic oxidative-inflammatory-nitrosative stress in chronic mountain sickness is associated with cognitive decline and depression . J Physiol , 2019 . 597 ( 2 ): p. 611 – 629 . OpenUrl CrossRef PubMed 99. Bakharev , V.D ., Investigation of memory during adaptation to high mountain conditions . Hum Physiol , 1981 . 7 ( 6 ): p. 409 – 14 . OpenUrl PubMed 100. Blogg , S.L. and M. Gennser , Cerebral blood flow velocity and psychomotor performance during acute hypoxia . Aviat Space Environ Med , 2006 . 77 ( 2 ): p. 107 – 13 . OpenUrl PubMed 101. Bloomfield , P.M. , et al. , Cocoa flavanols protect cognitive function, cerebral oxygenation, and mental fatigue during severe hypoxia . J Appl Physiol ( 1985 ), 2023. 135 ( 2 ): p. 475-484. 102. Bonnon , M. , M.C. Noël-Jorand , and P. Therme , Psychological changes during altitude hypoxia . Aviat Space Environ Med , 1995 . 66 ( 4 ): p. 330 – 5 . OpenUrl PubMed 103. Bonnon , M. , M.C. Noël-Jorand , and P. Therme , Criteria for psychological adaptation to high-altitude hypoxia . Percept Mot Skills , 1999 . 89 ( 1 ): p. 3 – 18 . OpenUrl CrossRef PubMed 104. Champod , A.S. , et al. , Effects of acute intermittent hypoxia on working memory in young healthy adults . Am J Respir Crit Care Med , 2013 . 187 ( 10 ): p. 1148 – 50 . OpenUrl CrossRef PubMed Web of Science 105. Chroboczek , M. , et al. , Exercise-Induced Elevated BDNF Concentration Seems to Prevent Cognitive Impairment after Acute Exposure to Moderate Normobaric Hypoxia among Young Men . Int J Environ Res Public Health , 2023 . 20 ( 4 ). 106. Crow , T.J. and G.R. Kelman , Effect of mild acute hypoxia on human short-term memory . Br J Anaesth , 1971 . 43 ( 6 ): p. 548 – 52 . OpenUrl CrossRef PubMed Web of Science 107. Falla , M. , et al. , Simulated Acute Hypobaric Hypoxia Effects on Cognition in Helicopter Emergency Medical Service Personnel - A Randomized, Controlled, Single-Blind, Crossover Trial . Hum Factors , 2024 . 66 ( 2 ): p. 404 – 423 . OpenUrl CrossRef PubMed 108. Falla , M. , et al. , Effect of oxygen supplementation on cognitive performance among HEMS providers after acute exposure to altitude: the HEMS II randomized clinical trial . Scand J Trauma Resusc Emerg Med , 2024 . 32 ( 1 ): p. 65 . OpenUrl CrossRef PubMed 109. Gerard , A.B. , et al. , Six percent oxygen enrichment of room air at simulated 5,000 m altitude improves neuropsychological function . High Alt Med Biol , 2000 . 1 ( 1 ): p. 51 – 61 . OpenUrl CrossRef PubMed 110. Guo , W.Y. , et al. , Physiological and psychological factors associated with onset of high-altitude headache in Chinese men upon acute high-altitude exposure at 3700_ m . Cephalalgia , 2017 . 37 ( 4 ): p. 336 – 347 . OpenUrl CrossRef PubMed 111. Hill , C.M. , et al. , Cognitive performance in high-altitude Andean residents compared with low-altitude populations: from childhood to older age . Neuropsychology , 2014 . 28 ( 5 ): p. 752 – 60 . OpenUrl CrossRef PubMed 112. Hohenauer , E. , et al. , The effects of normobaric and hypobaric hypoxia on cognitive performance and physiological responses: A crossover study . PLoS One , 2022 . 17 ( 11 ): p. e0277364 . OpenUrl CrossRef PubMed 113. Keeler , J.M. , et al. , Gamified assessment of cognitive performance during moderate hypoxia . PLoS One , 2023 . 18 ( 7 ): p. e0288201 . OpenUrl CrossRef PubMed 114. Koller , E.A. , et al. , The effects of acute altitude exposure in Swiss highlanders and lowlanders . Eur J Appl Physiol Occup Physiol , 1993 . 66 ( 2 ): p. 146 – 54 . OpenUrl CrossRef PubMed 115. Latshang , T.D. , et al. , Are nocturnal breathing, sleep, and cognitive performance impaired at moderate altitude (1,630-2,590 m)? Sleep , 2013 . 36 ( 12 ): p. 1969 – 76 . OpenUrl CrossRef PubMed 116. Legg , S.J. , et al. , Effects of mild hypoxia in aviation on mood and complex cognition . Appl Ergon , 2016 . 53 Pt B: p. 357-63. 117. Merz , T.M. , et al. , Cognitive performance in high-altitude climbers: a comparative study of saccadic eye movements and neuropsychological tests . Eur J Appl Physiol , 2013 . 113 ( 8 ): p. 2025 – 37 . OpenUrl CrossRef PubMed 118. Niedermeier , M. , et al. , Is decision making in hypoxia affected by pre-acclimatisation? A randomized controlled trial . Physiol Behav , 2017 . 173 : p. 236 – 242 . OpenUrl CrossRef PubMed 119. Noble , J. , J.G. Jones , and E.J. Davis , Cognitive function during moderate hypoxaemia . Anaesth Intensive Care , 1993 . 21 ( 2 ): p. 180 – 4 . OpenUrl CrossRef PubMed Web of Science 120. Parker , P.J. , et al. , Working Memory Capacity and Surgical Performance While Exposed to Mild Hypoxic Hypoxemia . Aerosp Med Hum Perform , 2017 . 88 ( 10 ): p. 918 – 923 . OpenUrl CrossRef PubMed 121. Pighin , S. , et al. , Loss aversion and hypoxia: less loss aversion in oxygen-depleted environment . Stress , 2014 . 17 ( 2 ): p. 204 – 10 . OpenUrl CrossRef PubMed 122. Quackenbush , J. , et al. , Respiratory Muscle Training and Cognitive Function Exercising at Altitude . Aerosp Med Hum Perform , 2016 . 87 ( 1 ): p. 18 – 25 . OpenUrl CrossRef PubMed 123. Ramírez-delaCruz , M. , et al. , Effects of different exposures to normobaric hypoxia on cognitive performance in healthy young adults.: Normobaric hypoxia and cognitive performance . Physiol Behav , 2025 . 288 : p. 114747 . OpenUrl CrossRef PubMed 124. Rice , G.M. , et al. , Dry-EEG Manifestations of Acute and Insidious Hypoxia During Simulated Flight . Aerosp Med Hum Perform , 2019 . 90 ( 2 ): p. 92 – 100 . OpenUrl CrossRef PubMed 125. Schega , L. , et al. , Effect of intermittent normobaric hypoxia on aerobic capacity and cognitive function in older people . J Sci Med Sport , 2016 . 19 ( 11 ): p. 941 – 945 . OpenUrl CrossRef PubMed 126. Schega , L. , et al. , Effects of intermittent hypoxia on cognitive performance and quality of life in elderly adults: a pilot study . Gerontology , 2013 . 59 ( 4 ): p. 316 – 23 . OpenUrl CrossRef PubMed Web of Science 127. Schlaepfer , T.E. , P. Bärtsch , and H.U. Fisch , Paradoxical effects of mild hypoxia and moderate altitude on human visual perception . Clin Sci (Lond ), 1992 . 83 ( 5 ): p. 633 – 6 . OpenUrl CrossRef PubMed 128. Shukitt-Hale , B. , L.E. Banderet , and H.R. Lieberman , Elevation-dependent symptom, mood, and performance changes produced by exposure to hypobaric hypoxia . Int J Aviat Psychol , 1998 . 8 ( 4 ): p. 319 – 34 . OpenUrl CrossRef PubMed Web of Science 129. Tesler , N. , et al. , Ascent to moderate altitude impairs overnight memory improvements . Physiol Behav , 2015 . 139 : p. 121 – 6 . OpenUrl CrossRef PubMed 130. Thomas , R.J. , et al. , Nocturnal hypoxia exposure with simulated altitude for 14 days does not significantly alter working memory or vigilance in humans . Sleep , 2007 . 30 ( 9 ): p. 1195 – 203 . OpenUrl CrossRef PubMed Web of Science 131. Turner , C.E. , et al. , Acute hypoxic gas breathing severely impairs cognition and task learning in humans . Physiol Behav , 2015 . 142 : p. 104 – 10 . OpenUrl CrossRef PubMed 132. Turner , C.E. , W.D. Byblow , and N. Gant , Creatine supplementation enhances corticomotor excitability and cognitive performance during oxygen deprivation . J Neurosci , 2015 . 35 ( 4 ): p. 1773 – 80 . OpenUrl Abstract / FREE Full Text 133. van der Post , J. , et al. , Evaluation of tests of central nervous system performance after hypoxemia for a model for cognitive impairment . J Psychopharmacol , 2002 . 16 ( 4 ): p. 337 – 43 . OpenUrl CrossRef PubMed 134. Van Dorp , E. , et al. , Inspired carbon dioxide during hypoxia: effects on task performance and cerebral oxygen saturation . Aviat Space Environ Med , 2007 . 78 ( 7 ): p. 666 – 72 . OpenUrl PubMed 135. Wu , Y. , et al. , Remote ischemic preconditioning improves spatial memory and sleep of young males during acute high-altitude exposure . Travel Med Infect Dis , 2023 . 53 : p. 102576 . OpenUrl CrossRef PubMed 136. Yan , X. , et al. , Adaptive influence of long term high altitude residence on spatial working memory: an fMRI study . Brain Cogn , 2011 . 77 ( 1 ): p. 53 – 9 . OpenUrl CrossRef PubMed 137. Yan , X. , et al. , Prolonged high-altitude residence impacts verbal working memory: an fMRI study . Experimental Brain Research , 2011 . 208 ( 3 ): p. 437 – 445 . OpenUrl CrossRef PubMed View the discussion thread. Back to top Previous Next Posted May 18, 2025. Download PDF Supplementary Material Data/Code Email Thank you for your interest in spreading the word about bioRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. You are going to email the following Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis Message Subject (Your Name) has forwarded a page to you from bioRxiv Message Body (Your Name) thought you would like to see this page from the bioRxiv website. Your Personal Message CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Share Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis Daniel J. McKeown , Douglas J. Angus , Ahmed A. Moustafa , Victor R. Schinazi bioRxiv 2025.05.15.654374; doi: https://doi.org/10.1101/2025.05.15.654374 Share This Article: Copy Citation Tools Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis Daniel J. McKeown , Douglas J. Angus , Ahmed A. Moustafa , Victor R. Schinazi bioRxiv 2025.05.15.654374; doi: https://doi.org/10.1101/2025.05.15.654374 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Area Neuroscience Subject Areas All Articles Animal Behavior and Cognition (7617) Biochemistry (17633) Bioengineering (13856) Bioinformatics (41841) Biophysics (21399) Cancer Biology (18529) Cell Biology (25422) Clinical Trials (138) Developmental Biology (13352) Ecology (19860) Epidemiology (2067) Evolutionary Biology (24281) Genetics (15582) Genomics (22461) Immunology (17700) Microbiology (40295) Molecular Biology (17140) Neuroscience (88413) Paleontology (666) Pathology (2823) Pharmacology and Toxicology (4813) Physiology (7632) Plant Biology (15107) Scientific Communication and Education (2042) Synthetic Biology (4284) Systems Biology (9808) Zoology (2267)