Gender Recognition in Point Light Walkers Displays: How Do Experts Compensate Insufficient Kinematic Cues?

The ability to recognize gender from biological motion can be based on shape (morphology) or on movement (kinematics), with the latter normally prevailing over the first. We investigated this topic by using real point light walkers stimuli recorded from healthy (H) and Parkinson’s disease (PD) volunteers. Sensitivity was measured in nonexperts (psychology students) and experts (physiotherapy students). Results showed that expertise interacts with the type of stimulus: Experts showed a comparable performance with both H and PD stimuli, while nonexperts performed significantly worst with PD stimuli. H and PD stimuli provided same gender-specific morphological cues (shoulder-to-hip ratio) but different gender-specific kinematic cues (torso and pelvic movements), which were preserved only in H stimuli. The results suggest that experts can use morphology to accomplish the task when kinematic cues are insufficient, while nonexperts’ judgments rely predominantly on kinematics.