CEREBELLUM-SUPERIOR TEMPORAL SULCUS INTERACTION IN EMOTION PROCESSING: A TRANSCRANIAL MAGNETIC STIMULATION STUDY

Recent research has established the participation of the cerebellum in affective functions and social cognition, including the processing of emotional facial expressions. It has been postulated that the cerebellum's involvement serves a supportive role to cortical areas, such as the superior temporal sulcus (STS), which consistently demonstrates involvement in the processing of emotional facial expressions and mirroring functions. However, the precise nature of the cerebellum's involvement and its specific functional relationship with other areas implicated in socio-affective processing remains uncertain. This thesis aims to address this knowledge gap by investigating the interaction between the STS and the cerebellum by combining offline and online transcranial magnetic stimulation (TMS) during an emotion discrimination task. The findings reveal that the activity of STS during an emotion discrimination task depends on the activation of the cerebellum. Specifically, the results demonstrate that the STS is causally recruited in emotional discrimination as shown by a reduced participants’ performance compared to the control condition (vertex) when the cerebellum works properly (no inhibition of the cerebellum). However, intriguingly, when the cerebellum is inhibited via offline TMS, the interference with STS activity does not significantly impact participants' performance. This observation suggests causal interaction within the cerebellum and STS that is fundamental to the participants’ ability to process emotional facial expressions.