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

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Chapter 1
Lloyd, di Pellegrino, and Roberts, 2004; Avenanti, Beuti, Galati, and Aglitoi, 2005).
For example, Avenanti and colleagues (2005) report that observing pain to another
person results in significant reductions in motor evoked potentials (MEPs). The
modulation of MEP amplitude correlated with subjective ratings of the sensory
aspects of pain attributed by the observer to the actor and was somatotopically
organised such that the reduced amplitude was specific to the muscles observed in a
painful event. These authors suggest that the findings provide evidence for a mirror-
pain resonance system in which observed pain is matched to the observer’s own
sensorimotor representation of pain. Such interpretation builds upon the findings of
mirror neurons within the monkey premotor cortex and inferior parietal lobule, which
respond both when a monkey performs an action and when the monkey watches
another person perform a similar action (Gallese, Fadiga, Fogassi, and Rizzolatti,
1996; Rizzolatti and Craighero, 2004) and evidence for similar mirror systems in the
human brain for not only action (Buccino et al., 2001), but also touch (Keysers,
Wicker, Gazzola, Anton, Fogassi, and Gallese, 2004; Blakemore et al., 2005; Ebisch,
Perucci, Ferretti, Del Gratta, Luca Romani, and Gallese, 2008), pain (Singer et al.,
2004; Aventani et al., 2005), disgust (Wicker, Keysers¸ Plailly, Royet, Gallese, and
Rizzolatti, 2003) and other emotions (Carr, Iacoboni, Dubeau, Mazziotta, and Lenzi,
2003).
Similar to the case of acquired “mirror pain” described above; developmental
cases of vision-touch or “mirror-touch” synaesthesia have also been documented
(Blakemore et al., 2005; Banissy and Ward, 2007). First reported in a single case
fMRI study (Blakemore et al., 2005), mirror-touch synaesthesia refers to cases of
synaesthesia in which observing touch to another person leads to tactile sensations on
the equivalent part of the synaesthete’s own body. In the original study by Blakemore