Effects of age on behavioural and eye gaze on Theory of Mind using movie for social cognition

Evidence has shown that older adults have lower accuracy in Theory of Mind (ToM) tasks compared with young adults, but we are still unclear whether the difficulty in decoding mental states in older adults stems from not looking at the critical areas, and more so from the ageing Asian population. Most ToM studies use static images or short vignettes to measure ToM but these stimuli are dissimilar to everyday social interactions. We investigated this question using a dynamic task that measured both accuracy and error types, and examined the links between accuracy and error types to eye gaze fixation at critical areas (e.g., eyes, mouth, body). A total of 82 participants (38 older, 44 young adults) completed the Movie for the Assessment of Social Cognition (MASC) task on the eye tracker. Results showed that older adults had a lower overall accuracy with more errors in the ipo-ToM (under-mentalising) and no-ToM (lack of mentalisation) conditions compared with young adults. We analysed the eye gaze data using principal components analysis and found that increasing age and looking less at the face were related to lower MASC accuracy in our participants. Our findings suggest that ageing deficits in ToM are linked to a visual attention deficit specific to the perception of socially relevant nonverbal cues.