Holistic vs. analytic visual perception of human body postures and actions: Similarities and differences with face perception.

Like human faces, human bodies can provide important visual information for social communication and interaction. It is generally assumed that human faces are processed holistically and not only analytically: Local facial features are not perceived and represented independently of each other; instead, a face is perceived as an integrated whole. One observation that has been taken as evidence for holistic face processing is the face inversion effect: Upside down presentation of faces disproportionally disrupts face processing in comparison to other object categories. We have shown previously that the face inversion effect is due to an impairment of holistic processing. Another piece of evidence is the composite face effect: Two identical top halves of a face tend to be perceived as being different when combined with different bottom halves. The body inversion effect (and the related composite effect) and its implications for a better understanding of the perception of human bodies and social perception in general is the main focus of the present project proposal. We will examine whether the body inversion effect and the composite effect in healthy observers is due to a failure of holistic processing. To this end, we will use experimental paradigms developed in our lab. The second major line of research of this project proposal is to apply the experimental procedures introduced before in patients who suffer from selective face processing deficits.