Why bodies? Twelve reasons for including bodily expressions in affective neuroscience.

Why bodies? It is rather puzzling that given the massive interest in affective neuroscience in the last decade, it still seems to make sense to raise the question 'Why bodies' and to try to provide an answer to it, as is the goal of this article. There are now hundreds of articles on human emotion perception ranging from behavioural studies to brain imaging experiments. These experimental studies complement decades of reports on affective disorders in neurological patients and clinical studies of psychiatric populations. The most cursory glance at the literature on emotion in humans, now referred to by the umbrella term of social and affective neuroscience, shows that over 95 per cent of them have used faces as stimuli. Of the remaining 5 per cent, a few have used scenes or auditory information including human voices, music or environmental sounds. But by far the smallest number has looked into whole-body expressions. As a rough estimate, a search on PubMed today, 1 May 2009, yields 3521 hits for emotion x faces, 1003 hits for emotion x music and 339 hits for emotion x bodies. When looking in more detail, the body x emotion category in fact yields a majority of papers on well-being, nursing, sexual violence or organ donation. But the number of cognitive and affective neuroscience studies of emotional body perception as of today is lower than 20. Why then have whole bodies and bodily expressions not attracted the attention of researchers so far? The goal of this article is to contribute some elements for an answer to this question. I believe that there is something to learn from the historical neglect of bodies and bodily expressions. I will next address some historical misconceptions about whole-body perception, and in the process I intend not only to provide an impetus for this kind of work but also to contribute to a better understanding of the significance of the affective dimension of behaviour, mind and brain as seen from the vantage point of bodily communication. Subsequent sections discuss available evidence for the neurofunctional basis of facial and bodily expressions as well as neuropsychological and clinical studies of bodily expressions.