Abstract

The compensatory eye movement (CEM) system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. We suggest that CEM can be modeled as a control system with three essential building blocks: a forward model that predicts the effects of motor commands; a state estimator that integrates sensory feedback into this prediction; and, a feedback controller that translates a state estimate into motor commands. We propose a specific mapping of nuclei within the CEM system onto these control functions. Specifically, we suggest that the Flocculus is responsible for generating the forward model prediction and that the Vestibular Nuclei integrate sensory feedback to generate an estimate of current state. Finally, the brainstem motor nuclei implement a feedback controller, translating state into motor commands. Electrophysiological recordings form the cerebellar flocculus seem to support this view.

Short biography

My main research aims to unravel the neurophysiological basis of learning. The specific aim is to elucidate the link between the cellular mechanisms of neural plasticity in the cerebellum and learning at a systems level. I carry out behavioural and electrophysiological experiments in mouse models. In collaboration with Prof de Zeeuw I have recently started a new lab for cerebellar work in primates. Furthermore, I undertake behaviour and fMRI studies in healthy humans, as well as patients. Patient studies in my lab are directed at people who have a deficit that can help elucidate the mechanisms of motor or executive control. Typically these are patients with either psychiatric, genetic or paraneoplastic disorders.

Recently we have adopted several stimulation techniques and we are shifting our focus from pure motor function to more executive functions of the cerebellum. The appeal of motor research is that both input and output can be straightforwardly made quantitative, so that all experimentation can be accompanied by predictive modelling. It is our focus to keep that same approach when expending our views.