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

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Chapter 7
hemisphere activity in affect recognition (e.g. Adolphs et al., 2000; Mitchell and
Crow, 2005; Pitcher et al., 2008; Pourtois et al., 2004; Van Lancker and Fromkin,
1973).
Two experiments were conducted. Experiment 1 sought to establish the
effects of cTBS targeted at rPM, rSI, or the vertex (cTBS control site) on participants’
abilities to complete a same-different auditory emotion recognition task (Figure 7.1;
Figure 7.2). Non-verbal emotional vocalisations (such as laughter or screams) were
used. These vocalisations are reliably recognised by human listeners (Sauter and
Scott, 2007; see also Meyer, Zysset, von Cramon, and Alter, K, 2005; Schröder, 2003)
and can be considered to be closer to emotional facial expressions than emotional
speech because they do not contain the segmental structure of emotionally inflected or
nonsense speech (Dietrich, Szameitat, Ackermann, and Alter, 2006; Scott, Sauter, and
McGettigan, in press; Scott, Young, Calder, Hellawell, Aggleton, and Johnsen, 1997).
In experiment 2, identical stimuli and cTBS parameters were used, but a new group of
participants were instructed to complete a same-different auditory identity
discrimination task. This enabled examination of any non-specific effects of cTBS
and whether the effects observed in experiment 1 were selective to affective
processing. Based on simulation accounts of emotion recognition it was predicted
that cTBS targeted at rPM and rSI would result in a disruption of participants’ ability
to discriminate the auditory emotions, but not identity, of others.
7.2 Methods
Participants
Twenty healthy naïve adult participants, 11 female and 9 male (aged 20 to
35years), took part in the study. All were right handed, had normal or corrected-to-
normal vision, and gave informed consent in accordance with the ethics committee of