Effects of adult aging on socioemotional perception : Evidence from behavior and brain

Abstract: Social perception plays a key role in our everyday interactions. It encompasses the ability to identify, understand, and react to the social cues that others express. However, how we process this social and emotional information changes with age and generally speaking, aging brings about a decline in this process, often leading to isolation, loneliness and reduced interpersonal functioning. The overall aim of this thesis was to study the underlying mechanisms of adult age-related changes in socioemotional perception, specifically of social attribute evaluation and emotion recognition. This was done in three studies.Study I explored age-related differences in the evaluation of seven common social attributes (attractiveness, competence, dominance, extroversion, likeability, threat, and trustworthiness) from computer-generated faces of varying intensity. Older adults rated faces as more attractive across all intensity levels, relative to their younger counterparts. Older adults also rated faces displaying low intensity of likeability as more likeable. Study II examined the effects of age on emotion recognition of positive and negative dynamic visual and auditory emotional expressions presented alone or in combination, and in nonlinguistic vocalizations. Older compared to younger adults showed diminished overall recognition accuracy and age-related differences were mainly observed in the auditory modality. Older adults also showed difficulties in recognizing anger, irritation, and relief expressions. In the case of the nonlinguistic vocalizations, age-related differences were observed for most emotions, regardless of valence. Study III investigated whether a single dose intranasal oxytocin facilitated the recognition of negative emotions from dynamic multimodal expressions and explored the neural correlates of this process with functioning magnetic resonance imaging. Behaviorally, older showed diminished recognition accuracy compared to younger adults but no oxytocin effects were found. Neurally, oxytocin caused brain activity reductions in the fusiform gyrus, dorsomedial prefrontal cortex, and medial orbitofrontal cortex.The findings of this thesis provide a more nuanced picture of how aging may influence socioemotional perception. Collectively, the findings suggest age comparability for most emotion categories and social attributes. These result patterns may conceivably be due to the computer-generated faces, several positive emotion expressions, and dynamic multimodal stimuli that were included in the studies. The findings also give a neuropsychobiological perspective to socioemotional processing in late adulthood through oxytocin intervention.