Final Report Summary - MULTSENS (Limits and prerequisites of information integration in the human brain: attention, awareness & vigilance)
Information integration is critical for the brain to interact effectively with our multisensory environment. Combining psychophysics, fMRI/EEG and computational modelling our results suggest that the brain arbitrates between sensory integration and segregation consistent with the principles of Bayesian Causal Inference by dynamically encoding multiple perceptual estimates at distinct levels of the cortical hierarchy. Only at the top of the hierarchy in anterior parietal cortices were signals integrated weighted by their bottom-up sensory reliabilities and top-down task-relevance into spatial priority maps that take into account the world’s causal structure. These multisensory integration processes were even partially preserved in the absence of consciousness and at reduced stages of vigilance. Critically, task-relevance and modality-specific attention to audition/vision modulated the auditory/visual weights in this integration process. Further, combining concurrent TMS-fMRI & Dynamic Causal Modelling, we have also shown that multisensory processing is affected by perturbations to parietal cortex. This research is complemented with studies in neglect patients to develop a multisensory model for neglect.
Collectively, our research has characterized the neural and computational mechanisms of the multifaceted interplay of MSI with attention, awareness & vigilance. It significantly advanced our understanding of information integration & segregation in the brain and may have important implications for diagnosis of patients with neglect & vegetative state.
Collectively, our research has characterized the neural and computational mechanisms of the multifaceted interplay of MSI with attention, awareness & vigilance. It significantly advanced our understanding of information integration & segregation in the brain and may have important implications for diagnosis of patients with neglect & vegetative state.