Abstract
It has been recently argued that, like faces, human bodies are processed by a specialized processing mechanism. Similar to faces, recognition abilities are significantly reduced for inverted relative to upright bodies (body inversion effect), which led to the suggestion that upright, but not inverted bodies, are processed by holistic mechanisms. In a series of experiments we examined the effect of part removal on the inversion effect of bodies and faces. Subjects were presented with a sequential matching task of bodies that were either identical or differ in position of the head, leg and hand. Our results show reduced performance and no inversion effect for headless bodies relative to complete bodies. In contrast, performance level and the magnitude of the inversion effect for bodies without hands or a leg were similar to complete bodies. Similar discrimination tasks with faces showed no difference between the magnitude of the face inversion effect for complete faces and faces without eyes or without a mouth. These findings suggest that heads may have a special status in the processing of body posture. In a final experiment subjects discriminated complete bodies that differ in hand and leg but with a fixed head position (fixed-head). Similar to headless bodies, performance for upright bodies and the body inversion effect where much reduced for the fixed-head complete bodies . Our findings show that the processing of upright bodies and the body inversion effect are markedly reduced whenever the head is absent or not relevant for discrimination. We conclude that the body inversion effect may be due to the difficulty in head discriminating, which is less visable in inverted bodies, rather than holistic processing per se. Our findings also suggest that the body inversion effect may not reflect the same kind of mechanisms that generate the face inversion effect.