Past Projects

Multisensory causal inference in cortical hierarchies and its alterations in schizophrenia

Humans integrate stimuli from different sensory systems into a coherent and reliable representation of the environment. Yet, the human brain only integrates the stimuli, weighted proportional to their sensory reliability, if a small spatial and temporal disparity between the stimuli suggests a common cause of the stimuli. If large discrepancies suggest independent causes of the stimuli, the brain segregates the stimuli. Our previous and current work suggests that the dorsolateral prefrontal cortex (dlPFC) first determines the causal structure of the stimuli based on their discrepancy, and then the anterior intraparietal sulcus (aIPS) integrates the stimuli in a reliability-weighted manner in the case of a common signal source. However, this model of multisensory causal inference in cortical hierarchies has so far been little tested. In addition, schizophrenia could alter multisensory causal inference, leading for example to hallucination. In the project, we investigate where, when and how cortical hierarchies make a causal decision and integrate or segregate audiovisual stimuli. In EEG and fMRI studies in healthy volunteers and schizophrenia patients, we are investigating the role of the dlPFC in causal decisions and the aIPS in the integration of audiovisual stimuli. In a TMS study, we then investigate whether both regions also play a causal role in causal decisions and integration.

Duration of the project: 2018-2021

ETI: The interplay of multisensory causal inference and attention in audiovisual perception

Psychophysical study on the influence of attention on explicit causal inferences in audiovisual perception. See the resulting DFG project MultiAttend: DFG project ‘MultiAttend’

Project duration: 2021-2022