abstract Charles Wilson

Charles Wilson (Stem Cell & Brain Research Institute, INSERM U846, Lyon, France)

What are the neurophysiological markers of cognitive control, and can they be used to indicate the early stage of a dopaminergic lesion?

Flexibility and efficiency of behaviour involves monitoring performance and changing levels of cognitive control in order to properly adapt to the current context. Studies including those from our laboratory have revealed a number of neurophysiological markers of these processes. In particular evoked potentials recorded over medial frontal cortex reflect the nature of feedback in a task requiring behavioural adaptation, and frontal beta oscillations are associated with top-down control mechanisms. Amongst others we have also established that these markers are dependent on the dopamine system. Hence we are studying whether these markers can be used to indicate the early stages of a dopaminergic lesion, the best-known example of which is the pre-motor phase of Parkinson’s disease. I will explain how we are developing our understanding of cognitive control and its neurophysiological markers using electrophysiology in macaque monkeys. I will then describe a project to follow the changes in these markers during the evolution of a slow progressive DA lesion designed to be an analogue of the pre-diagnosis (pre-motor-symptomatic) phase of Parkinson’s disease. I will show evidence for evolution in feedback potentials that are not related to cognitive deficits, and evidence for changes in beta oscillatory patterns that appear to be linked to motivation and attentional effort. These markers are potentially exploitable to characterize DA system alteration and to evaluate therapies.