Personality and social cognition in neurodegenerative disease

Purpose of review Neurodegenerative diseases often cause focal damage to brain structures mediating social cognition and personality, resulting in altered interpersonal communication and behavior. We review recent research describing this phenomenon in various aspects of social cognition. Recent findings Corresponding to their pervasive socioemotional deficits, patients with frontotemporal dementia perform poorly on laboratory-based tasks including recognizing emotions, attending to salient information that guides social behavior, representing social knowledge, comprehending others' mental states, and maintaining insight to their own difficulties. Together with poor executive and regulation mechanisms, these social cognition deficits ultimately impact behavior. Patients with logopenic and nonfluent primary progressive aphasia have some deficits recognizing emotional prosody, whereas those with the semantic variant show more widespread deficits in social comprehension. Although Alzheimer's disease patients perform poorly on some social cognition tasks, this typically reflects general cognitive impairment, and their real-life social functioning is less affected than in diseases targeting frontotemporal structures. Studies in motor diseases such as Parkinson's suggest some degradation of emotion recognition and social comprehension, which should be investigated further. Summary We summarize recent findings concerning perception and evaluation of socioemotional information, social knowledge storage and access, advanced information processing mechanisms, and behavioral response selection and regulation across various neurodegenerative diseases.