Emotion recognition from faces and bodies in Parkinson's disease and its relationship to MRI-based brain volumetry.

Although Parkinson's disease (PD) is primarily defined by motor symptoms, non-motor manifestations-including deficits in social cognition-are increasingly recognized for their impact on daily functioning. Emotion recognition impairment is one such deficit, but prior research has mainly focused on facial expressions, neglecting other socially relevant cues such as body postures. This study examined recognition of emotions from both faces and bodies and their cognitive and neuroanatomical correlates in non-demented patients with PD. We enrolled 25 individuals with mild to moderate PD and 24 age-matched healthy controls. Emotion recognition was assessed with validated facial (ER-40) and bodily (BR-40) tasks. Cognitive function was evaluated with the Montreal Cognitive Assessment, Dementia Rating Scale-2 and Frontal Assessment Battery. Motor symptoms were rated using the MDS-UPDRS Part III. Structural MRI data were analyzed with FreeSurfer. Compared with controls, patients with PD showed a specific impairment in recognizing emotions from body postures, despite comparable overall performance to controls. Within the PD group, poorer recognition was associated with greater cognitive impairment and higher bradykinesia subscores. MRI volumetry linked emotion recognition performance to the volumes of the cerebellar white matter, hippocampus, and left nucleus accumbens. In addition to these structures, facial emotion recognition was specifically related to cerebellar cortical volume, whereas body posture recognition showed associations with the rightputamen, and right amygdala. These findings highlight modality-specific social cognitive deficits in PD, related to both cognition and structural brain changes.