The role of the cerebellum for feedback processing

• Applicants: Privatdozentin Dr. Martina Minnerop; Professorin Dr. Jutta Peterburs; Professorin Dr. Dagmar Timmann-Braun
• Subject Area: Human Cognitive and Systems Neuroscience
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 437661157

While the cerebellum has traditionally been thought to be merely involved in motor functions, a recent paradigm shift has emphasized cerebellar contributions also to cognitive functions. However, the mechanisms of cerebellar contributions to non-motor functions have not been clarified yet. The cerebellum’s uniform neuro-architecture and its closed input-output loops for communication with the cerebral cortex suggest that the cerebellum may serve overarching functions in the motor and cognitive domain. These may include timing, generation of internal models, (sensory) prediction, and sequence detection, and therefore functions that fit well within a general framework of performance monitoring, prediction, and error-based learning. The present research program aims to investigate the role of the cerebellum for error and feedback processing. The proposed experimental paradigms also require prediction and test to what extent these processes depend on feedback timing, so that the results of the present project will help to integrate multiple theories of cerebellar contributions to non-motor functions. The proposed research program investigates the role of the cerebellum for learning from and processing of immediate vs. delayed feedback by means of complementary patient studies, electrophysiological recordings (EEG), and brain stimulation (single-pulse TMS) in healthy subjects. The patient studies also include precise lesion mapping and quantification as well as extensive analysis of cerebellar functional and structural connectivity in order to elucidate the specific role of cerebellar subregions. The present project therefore utilizes a comprehensive multi-method approach to advance our understanding of cerebellar function. Study 1 investigates a sample of patients with progressive cerebellar degeneration and matched controls with an EEG-adaptation of a probabilistic learning task involving immediate and delayed feedback. Extent and localization of cerebellar damage will be investigated based on lesion-symptom-mapping and functional and structural connectivity analyses, and results will be related to behavioral and neuronal indices of feedback processing and feedback learning. Since patients with cerebellar degenerative disease usually present with a rather diffuse cerebellar pathology, Study 2 investigates patients with focal, vascular cerebellar lesions and healthy controls with the same task. Due to the focality of the lesion in these patients, results will likely allow for a better assessment of the role of specific cerebellar subregions and cerebello-cerebral networks. Study 3 is aimed to elucidate temporal aspects of cerebellar involvement in processing of immediate and delayed feedback by applying a “virtual lesion” approach. To this end, single-pulse and cerebellar TMS (and single-pulse TMS delivered to the vertex as a control site) delivered at different time points during the task will be applied in a sample of healthy control subjects.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Christian Bellebaum