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

173
Chapter 9
system (Rizzolatti and Craighero, 2004) and has been reported in a number of fMRI
studies on facial expression evaluation (Carr et al., 2001; Dapretto et al., 2006;
Hennenlotter et al., 2006; Kesler-West et al., 2001; Seitz et al., 2008). The lack of
impairment following cTBS to rIFG would suggest that although this region may be
involved in facial expression recognition (Carr et al., 2001; Dapretto et al., 2006;
Hennenlotter et al., 2006; Kesler-West et al., 2001; Seitz et al., 2008), it may not be
critical to the process. Other components of motor simulation may play a more
critical in facial expression discrimination (e.g. premotor cortex as studied in chapter
7) and future studies should address this.
Further possibilities for future research include combining TMS with other
methodologies to consider the role of cortico-cortical interactions play in
discriminating another’s expressions. Moreover, while the effects of online TMS are
spatially discrete, the effects of offline stimulation will spread to other cortical areas
along the greatest lines of conductivity from the stimulated area. By combining cTBS
with fMRI paradigms one should be able to assess any secondary effects of cTBS on
other regions involved in expression recognition.
9.7 General Summary
In summary, this thesis has investigated the neurocognitive and perceptual
profiles of mirror-touch synaesthesia (Chapters 2-5). I have provided a
neurocognitive model of the condition (which provides testable predictions for future
studies) and used mirror-touch synaesthesia as a tool to inform us about the
neurocognitive mechanisms of synaesthesia more generally. The studies presented
have also used mirror-touch synaesthesia as a model to inform us about the impact
that heightened sensorimotor activity has on social cognition (Chapters 4 and 5), and
the findings from these studies are compatible with research presented in chapters 7