Mechanisms of deviance processing: Probing neurocomputational models of prediction and adaptation under different task conditions in the human brain

• Applicant: Dr. Insa Schlossmacher
• Subject Area: Biological Psychology and Cognitive Neuroscience ; Human Cognitive and Systems Neuroscience
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 468787028

Detecting changes in sensory input can be regarded as the basis of all perceptual processing. Uncovering how the brain processes these changes – also called deviance – on a mechanistic level has sparked a growing body of research in neuroscience. In particular, the concept of predictive processing has been put forward as a compelling explanation for deviance processing in oddball designs. Regarding perception, this implies that sensory input is compared to an internal model, and that deviant stimuli evoke a prediction error, which is then propagated through the brain. However, alternative models, such as adaptation of brain activation to expected stimuli are also able to explain deviance effects, thereby questioning the assumptions of predictive processing. Moreover, it is still unknown to which degree these mechanisms are utilized across the sensory processing hierarchy, e.g. from early stimulus-driven stages up to later higher-order associative stages. Furthermore, it has neither been investigated systematically whether and how task conditions like awareness and task relevance influence the mechanism at play during deviance processing. Finally, it remains unclear how results can be generalized across sensory modalities. This proposal addresses these open questions by a series of combined EEG-fMRI experiments that vary awareness and task relevance of auditory and visual roving oddball sequences. Computational modelling of single-trial responses will reveal the neurocomputational mechanisms of deviance processing to explain the spatio-temporal brain activation pattern depending on task conditions and sensory modality. Thus, the project is expected to systematically reveal how, where and when neurocomputational mechanisms of deviance processing differ.

• DFG Programme: Research Grants
• Co-Investigators: Dr. Maximilian Bruchmann; Professor Dr. Thomas Straube