Cognitive reserve, emotion perception and theory of mind in non-demented Parkinson's disease

The Cognitive Reserve (CR) hypothesis attempts to account for individual differences in vulnerability to age- or pathology-related brain changes, where lifetime experiences (e.g., education, literacy attainment) have protective effects on cognitive decline. While evidence suggests CR proxies predict cognitive performance in Parkinson's disease (PD), it is less clear whether CR proxies attenuate decline on social cognition tasks. This study examined the influence of distinct CR proxies on performance on social cognition tasks assessing theory of mind and emotion perception. Twenty non-demented PD patients and 20 healthy control participants completed the Test di Intelligenza Breve (TIB) and the Cognitive Reserve Index questionnaire (CRIq) as proxies of CR and the Story-based Empathy Task (SET; emotion attribution and intention attribution), the FACE Test and the Emotion Recognition Task (ERT; faces only, voices only and faces-voices) as tests of social cognition. Older age and having PD were associated with poorer performance on SET emotion attribution, while older age, having PD and lower TIB and CRIq scores independently predicted poorer performance on SET intention attribution. For the FACE Test, a lower TIB index predicted poorer performance. Finally, for ERT performance, older age and being male independently predicted poorer performance on faces only; older age and lower TIB scores predicted poorer performance on voices only; and being male and having lower TIB scores predicted faces-voices performance. This study demonstrated that CR is associated with performance on social cognition tasks, but it depends on the proxy adopted, and the protective role is not specific to PD.