Behavioral and electrophysiological correlates of intact and scrambled body perception

Intact faces and bodies elicit two prominent electrophysiological components (P100 and N170). The N170 is thought to be related to the structural encoding and configural processing of faces and bodies. The aim of the present study was to investigate whether intact faces and bodies as well as scrambled faces and bodies elicit the same component. This would imply that similar as faces, bodies are encoded as a whole.

We used a matching to sample task and two manipulations validated as an assessment of configural processing in previous studies: the inversion effect and intact versus scrambled stimulus presentation.

For both categories, performance was better for intact compared to scrambled stimuli. Additionally, stimulus distortion seems to abolish the body but not the face inversion effect. On the electrophysiological level, we found enhanced N170 amplitudes for intact faces and bodies compared to scrambled stimuli. The opposite pattern engaged in the time-window of the P100. Furthermore, for the N170 we observed an inversion effect for intact but not scrambled bodies.

First-order relational information are important for the perception of bodies and might be processed in the N170 time-window. Disrupting this information interacts with the inversion effect.

The current data suggest that faces and bodies might be processed by distinct mechanisms as the experimental manipulation affected faces in a different way than bodies.