Our sense of our body is the foundation of our subjectivity, and our understanding of the subjectivity of others. Through the mapping of other people’s actions, sensations (i.e. touch, pain) and expressions onto our own sensorimotor neural systems we are able to recognise them as, like ourselves, possessing of subjective experience. However our bodies can also differ from those of others and some of these differences, in particular skin colour, can form the basis of pernicious divisions between social ingroups and outgroups. Recent studies have shown that observing actions or sensations) on the bodies of those with a different skin colour to oneself leads to a reduced mapping of the others’ bodies onto our own sensorimotor systems. Indeed one study  found that this difference was directly correlated with participants’ implicit racial bias, suggesting that social attitudes affect these unconscious sensorimotor mappings. One question which has been unexplored until now is how important such differences in skin colour are for determining what is and is not part of our own bodies.
To answer this question, we used the rubber hand illusion (RHI) a procedure that uses synchronous touch to a fake hand and the participants own, unseen, hand to trick participants into feeling that a fake, rubber hand is their own . A group of white participants experienced the RHI procedure with both a white and a black rubber hand. We measured the strength of the illusion using questionnaires and objective measures such as levels of physiological arousal measured through skin conductance in response to the application of painful stimuli to the rubber hand. We also measured participants’ implicit racial bias both before and after they had experienced the RHI for the hands of both skin colours. Overall participants’ felt the illusion for both the white and black hand but there was an interesting difference between their subjective reports and the objective measures . While introspectively participants reported greater feelings of ownership for the white than the black hand, there was no effect of skin colour for either behavioural measure. In addition we found that, although participant’s pre RHI racial bias did not seem to effect the subjective strength of the illusion for the black hand, the post RHI racial bias was lower for those who reported feeling ownership over the rubber hand of either skin colour.
It seems then that surface features like skin colour are relatively unimportant for the experience of body ownership. At least on the level of body-ownership the brain is more interested in other factors such as the synchrony of visual and tactile signals or the gross visual form of the object being touched . However, the finding that experiencing ownership over a black hand might influence participants’ racial bias is a first step towards showing that bottom up sensory information about the body can have an effect on our higher level social perceptions of others. Our lab is currently working to investigate such effects in a more systematic manner.
Find ‘Beyond the colour of my skin: How skin colour affects the sense of body-ownership’ here
About Harry Farmer
Harry Farmer is a PhD student in the Lab of Action and Body at Royal Holloway, University of London. His current research focuses on the relationship between social interaction and the experience of one’s own body in sensation (e.g. sense of body-ownership) and action (e.g. sense of agency). He is supervised by Dr Manos Tsakiris and funded as part of the Narcissus and Echo Project by the Volkswagen Foundation’s “European Platform for Life Sciences, Mind Sciences and Humanities”. More generally Harry’s research interests encompass the role of the body and body representations in both cognition and conscious experience. He previously gained a Joint Honours BSc in Psychology and Philosophy at the University of Bristol and an MSc in Psychological Research at the University of Oxford and has also worked for City and Hackney Mind, a mental health charity. A full list of his research publications can be found here.
 Avenanti A, Sirigu A, & Aglioti SM (2010). Racial bias reduces empathic sensorimotor resonance with other-race pain. Current biology, 20 (11), 1018-22 PMID: 20537539
 Botvinick M, & Cohen J (1998). Rubber hands ‘feel’ touch that eyes see. Nature, 391 (6669) PMID: 9486643
 Farmer H, Tajadura-Jiménez A, & Tsakiris M (2012). Beyond the colour of my skin: How skin colour affects the sense of body-ownership. Consciousness and cognition PMID: 22658684
 Tsakiris, M. (2010). My body in the brain: A neurocognitive model of body-ownership. Neuropsychologia, 48(3), 703–712.