In the brain, unlike conventional computers, cognitive processes like memory and perception are tightly interlinked with their physical substrate. Understanding the biophysical mechanisms behind the repertoire of dynamical phenomena the nervous system can generate is therefore an essential part for understanding brain function in general. We gain insight into the material basis of cognition by developing biophysically realistic computer models that can account for neurophysiological observations and relate them to cognitive function, by probing neural networks 'in a dish', and by analyzing neurophysiological data primarily using methods derived from nonlinear dynamics.

Current research projects focus on the biophysical mechanisms and neural dynamics underlying higher cognitive functions associated with the prefrontal cortex, and their regulation through dopamine. The prefrontal cortex is involved in the organization of behavior in time, the prediction of future outcomes based on observed temporal sequences, and flexible responding in changing situations. Current research projects include:

• Development of a biophysically detailed prefrontal cortex model including its dopamine modulation, based on detailed morphological reconstructions and electrophysiological recordings of prefrontal neurons.

• Analysis of multiple unit in vivo recordings from behaving animals placed in working memory and cognitive flexibility tasks, in particular developing methods based on nonlinear dynamics (in collaboration with Dr Jeremy Seamans, UBC, Vancouver; funded by the Canadian Institutes of Health Research).

• Neurodynamical and computational investigations of the 'dual-state theory' of prefrontal dopamine function (Durstewitz & Seamans), with its implications for schizophrenia and human genotypes.