Age-related differences in emotion recognition are linked to cognition and brain structure and function

People show significant individual differences in their ability to recognise emotions. These differences are particularly pronounced in ageing, with dementia, after brain lesions and as a function of mental health factors, such as depression. Older people, for example, tend to have poorer recognition of negative emotions, such as anger, fear and sadness, but better recognition of positive emotions, such as happiness. This ‘positivity bias’ has been suggested to support mental well-being in ageing, but has also been found in association with cognitive decline and brain lesions. Here, we investigated the brain correlates of increased positivity bias with age. We used multimodal brain imaging in a large, population-derived cohort across the adult lifespan, together with a standard emotion recognition task using facial expressions. We first replicated previous behavioural findings showing increased perceptual thresholds in older adults for detecting negative emotion, but reduced threshold for positive emotion, even after accounting for general face recognition abilities. This positivity bias was strongly associated with lower cognitive performance in older people, but not with (non-clinical) depressive symptoms. This age-related bias was associated with reduced grey matter volume in bilateral anterior hippocampus-amygdala. Moreover, resting-state functional connectivity between these regions and orbitofrontal regions was greater with increased positivity bias. Together, our results suggest that the age-related positivity bias is associated with cognitive decline and structural and functional brain differences. Similar to neurodegenerative conditions, a positivity bias in emotion recognition may reflect an early marker of neurodegeneration, which could be confirmed in longitudinal studies.