The role of the MTG in negative emotional processing in young adults with autistic traits: a fMRI task study

Abstract Individuals with autistic traits are those within the normal population who demonstrate social, communication, and cognitive impairments but who do not meet the clinical threshold for autism spectrum disorder (ASD). ASD is a pervasive neurodevelopmental disorder associated with deficits in high-level cognitive functions such as negative emotion processing and social cognitive processing, and people with autistic traits also have these impairments. Few previous studies have explored negative emotion processing in people with autistic traits using task-based functional magnetic resonance imaging (fMRI). In this study, we focused on the behaviors of a large sample (N=104) of Chinese individuals with different levels of autistic traits, who we tested using a popular questionnaire called the autism spectrum quotient (AQ). We then applied task fMRI to determine negative emotion processing and social cognition associated with differences in brain activation and functional connectivity. The results mainly showed significantly positive activation in the right middle temporal gyrus (MTG), and the right hippocampus gyrus (HG) in multiple regression analysis. More importantly, mediation analysis showed that the right MTG suppresses the relationship between AQ (total) score and negative emotional processing, showing that a higher autistic trait score in individuals leads to a smaller difference between the rating of negative images and the neutral images. Furthermore, generalized psychophysiological interaction analyses (gPPI) analysis also suggested that the right MTG shows significant functional connectivity (FC) with the left parahippocampal gyrus (PHG), suggesting that individuals with autistic traits have high level of spontaneous negative emotion. According to these findings, we assumed that the MTG might have a specific effect on processing negative emotion in individuals with autistic traits related to weaker to social emotion ability. The emotion perception mechanisms in the MTG region may be affected by atypical negative emotion processing in other brain regions such as HG and PHG, during a negative emotion processing task with socially emotion-relevant information in individuals with autistic traits.