This program examines the brain networks for decision making in sensory and motor domains. In the motor domain, the decisions include choices about what actions to take, bringing together two broad avenues of research: (1) the processes of volition, and agency, by which our choices and actions seem voluntary, and (2) the contextual constraints on appropriate actions or decisions, including knowledge of behavioral ‘rules’ instructions to act inhibit. In the sensory domain, decisions include the identification of a match – or mismatch – between predicted and actual sensory inputs. Despite the apparent distinction between sensory and motor systems, there are close interactions, which are explored further in the context of neurological disease.
Many neurological disorders can affect decision making and lead to impulsive and poor quality decision, with a variety of consequences in everyday life as well as laboratory studies. People may make impulsive decisions or actions; fail to update behavior to take into account new information or a change of context; or take actions which have predictably bad outcomes. We study the impact of Parkinson’s disease, brain injury and some types of dementia, as well as healthy ageing on such behavioral decisions.
The research explores not only the impact of the disease on the behavioral decisions themselves, but also the underlying mechanisms. Our studies include magnetic resonance imaging to measure brain structure and function, magneto-encephalography (MEG) to examine brain networks, direct recording from the cerebral cortex in patients (electrocorticography) and focal perturbations of brain function by transcranial magnetic stimulation (TMS) and post surgical lesions. We are especially interested in the way that multiple brain regions need to work together to make decisions. We therefore analyze brain network connectivity using linear and non-linear dynamic causal models (DCM), graph theory and coherence within brain networks.