Interdisciplinary Network of Researchers in Touch
Thursday 25th July, 2019
|14:15-14:30: Symposium in Lecture Theatre, A01||Body representation across the lifespan: Evidence from mirror-touch synaesthetes and typical adults|
An accurate representation of the size and shape of our body parts is necessary to infer their spatial location and interact with our environment. Explicit knowledge of the metric properties of the body is typically accurate in healthy adults. Implicit representations are generally less accurate, but more malleable, and are improved in highly trained individuals. To date, no research has investigated whether this implicit body model may be modulated vicariously by exposure to other bodies. Individuals with mirror-touch synaesthesia (MTS) experience vicarious tactile sensations on their own body simply from watching another person being touched. These individuals also report feeling that their body changes in size and shape when viewing distorted bodies. These subjective reports indicate a broader tendency towards self-other blurring of body representations in MTS, beyond tactile perception. To examine this, the present study measured objective accuracy of the body model in MTS. Participants with MTS and controls (aged 20-69 years) completed an implicit measure of their own hand representations, in which they were required to point to several landmarks on the hands, with eyes closed. They also completed an explicit measure, in which they judged the shape of their hands relative to visual exemplars. Implicit body representations were found to be more accurate in older participants. However, no significant difference was found between MTS and age-matched controls. The results indicate the development of an accurate body model throughout adulthood, and demonstrate the stability of the body model to vicarious modulation, despite subjective experience of self-other blurring in MTS.