Mirror-touch synaesthesia: the role of shared ... - UCL Discovery

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Chapter 1
aroused some interest, failure to develop an objective approach to confirm the
phenomenon resulted in a decline in research. It was not until the advent of the
development of new behavioural and neurophysiological measures which could be
used to corroborate self reports that the topic of synaesthesia returned as a topic of
legitimate scientific investigation (Baron-Cohen et al., 1987; Cytowic and Wood,
1982; Marks, 1975; see Ramachandran and Hubbbard, 2001; Rich and Mattingely,
2002; Sagiv, 2004 for reviews).
Since this time, research into the topic of synaesthesia has grown rapidly with
a focus moving beyond exploring the reality of the condition to consider how
synaesthesia can be used to inform models of typical cognition in domains such as
numerical cognition (Cohen Kadosh and Henik, 2007), language (Simner, 2007),
multisensory processing (Sagiv and Ward, 2006), imagery (Barnett and Newell, 2008;
Spiller and Jansari, 2008), and attention (Treisman, 2004). In this introductory
chapter, I will review this literature by describing studies on the prevalence,
authenticity and aetiology of synaesthesia. The focus of this thesis is to investigate a
newly documented type of synaesthesia, mirror-touch synaesthesia (in which
individuals’ experience tactile sensations on their own body simply when observing
touch to others) and to use this condition to examine more general neurocognitive
processes in social cognition. In this chapter, I will introduce research investigating
synaesthesia involving touch and consider the evidence that mirror-touch synaesthesia
relies upon similar mechanisms to multisensory interactions which are shown in non-
synaesthetic individuals. Finally, I will discuss how synaesthesia may be used to
inform typical models of cognition and discuss the role of sensorimotor simulation in
social cognition.