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

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Chapter 7
Singer, Seymour, O’Doherty, Kaube, Dolan, and Frith, 2004; Wicker, Keysers¸
Plailly, Royet, Gallese, and Rizzolatti, 2003) has provided a candidate
neurophysiological mechanism for such shared representations in emotion
recognition. These brain regions may, in part, aid emotion recognition because they
enable the observer to match the observed emotion within cortical areas active during
the observer’s own experience of the perceived emotion (Carr et al., 2003;
Hennenlotter et al., 2005; Jabbi, Swart and Keysers, 2007; Leslie, Johnsen-Frey, and
Grafton, 2004; van der Gaag, Minderaa, and Keysers, 2007). Consistent with this,
functional brain imaging studies indicate that components of classical and extended
mirror systems (including premotor cortex and primary somatosensory cortex) are
recruited when perceiving others’ facial emotions (Hennenlotter et al., 2005; Leslie,
Johnsen-Frey, and Grafton, 2004; Montgomery and Haxby, 2008; van der Gaag,
Minderaa, and Keysers, 2007); that primary somatosensory cortex is activated when
judging another’s facial emotion (Winston, O’Doherty, and Dolan, 2003); and that the
auditory-motor mirror system is activated during the perception of non-vocal emotion
expressions (e.g. hearing somebody laughing; Warren et al., 2006). Further, in
chapters 4 and 5 I show that facilitated sensorimotor simulation (in mirror-touch
synaesthesia) is linked to heightened emotional empathy and emotional expression
recognition. In attempt to assess what impact suppressing sensorimotor activity has
on the expression recognition abilities of healthy adults, here (and in chapter 8) I use
TMS in non-synaesthetes to assess whether sensorimotor activity plays a central role
in our ability to recognize the emotions of others.
In the visual domain, there is growing evidence that sensorimotor activity
plays a causal role in facial emotion recognition. Neuropsychological findings
indicate that deficits in the recognition of facial affect are related to damage within