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

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Chapter 7
Figure 7.1 Summary of cTBS and task protocol. Participants completed a samedifferent
auditory emotion (Experiment 1) or identity (Experiment 2) matching task.
Both experiments consisted of three testing sessions conducted over three nonconsecutive
days. At each testing session one of the three brain regions was
stimulated (rSI, rPM or the vertex). In each session, the task was completed prior to
and 5 minutes following cTBS to each site. The 5 minute rest period was based on
the observed time course of effects seen in the motor cortex. During the task, trials
began with a fixation cross followed by the presentation of a prime emotion via
headphones. Non-verbal auditory emotions of amusement, sadness, fear or disgust
were used. After 500 milliseconds a second emotional expression was presented
which was either the same or different from the target. In experiment 1, participants
were asked to indicate whether the emotional expression was the same or different to
the prime using a key press. In experiment 2, a new group of participants were asked
to indicate whether the emotional expressions were produced by the same or different
person. The need for speed and accuracy were emphasised.
TMS parameters and coregistration
TMS was delivered via a figure of eight coil with a 70mm diameter using a
Magstim Super Rapid Stimulator (Magstim, UK). An offline cTBS paradigm was
used, which consisted of a burst of 3 pulses at 50Hz repeated at intervals of 200ms for
20 seconds, resulting in a total of 300 pulses. This paradigm was used to prevent any
influence of online auditory and proprioceptive effects of TMS on task performance