Perception of Biological Motion: No Sensitivity Differences in Patients With Parkinson’s Disease

According to Hommel’s theory, motor system partially mediates action perception by simulating or embodying observed actions. Previous studies failed to demonstrate motor repertoire compatibility effects, probably because the point light walker (PLW) stimuli used were recorded only from healthy people, and showed that sensitivity to biological motion may be reduced in Parkinson’s disease (PD) with motor dysfunction. We hypothesize that perceptual ability in PD patients could be improved by watching PLWof patients with the same disease condition. Two groups of participants (24 healthy and 33 patients with PD) underwent to a gender recognition task with PLW stimuli obtained from healthy and PD actors. The results show a better sensitivity to biological motion in females than males. Moreover, gender recognition has been worsened by watching parkinsonian PLW. Our data do not show a compatibility effect, neither confirm previous data about an impaired perception of biological motion in PD patients.