MBraiS · The Multisensory Brain in a Social World: When, Where, and How Do Multisensory and Social Processes Interact in the Brain?

Sensory experiences are a vital aspect of human existence. In everyday life, our senses are flooded with input, constantly picking up multiple unisensory signals at once. In our brain, these incoming signals are either processed separately or integrated into one unitary percept a process known as ""multisensory integration"". Intriguingly, this integration process can be affected by the social context people find themselves in, for example such that people perceive certain perceptual illusions more intensely when experiencing them jointly with another person. To date, this effect has been observed on a behavioral level yet it is not clear what happens in the human brain on a neurophysiological and computational level. Thus, in the proposed research I will investigate the interplay between multisensory and social processes from a neuroscientific perspective. I aim to (1) identify when the social context affects multisensory processing, (2) localize where in the brain the social context affects multisensory processing, and (3) model how the social context affects multisensory processing. To this end, I will conduct experimental studies, using a combination of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), complemented by a cognitive modeling approach. I will use EEG to address the temporal (when) and fMRI to address the spatial processing dimension (where). To address the third objective (how), I will fit a Bayesian causal inference model to the behavioural data. The overarching goal of my research is to extend the current view on multisensory processing by a social component, thereby contributing to a more holistic account of human perceptual processing.""