Thesis defense Johannes Keyser (Donders series 491)

11 March 2021

Promotor: Prof. dr. W.P. Medendorp
Co-promotor: Dr. ing. L.P.J. Selen

(Multi)sensory processing for planning and control of reaching movements

Throughout the day, we perform various reaching movements to move our hands to specific locations — from snoozing the alarm in the morning until switching off the lights at night. Most of these movements are sensory-guided, but it remains unclear how our brain processes this information in movement control. A contemporary framework, referred to as optimal feedback control (OFC), affords a flexible, task-dependent link between sensory feedback and motor output, which is mostly ignored by more traditional theories. This thesis tests the OFC theory with experiments that perturb vestibular, visual, and proprioceptive information during reaching movements. We show that these perturbation result in quick and task-specific reach corrections, as predicted by OFC. However, we also show that the integration of multiple sensory perturbations takes longer than predicted by this framework. Finally, we interpret movement planning in stroke patients within this general framework. Together, the results from this thesis contribute to the development of an over-arching theory of movement control.