"Neural mechanisms of spatial cognition"
Current Research and Interests
1. Investigation of the role of the hippocampus in spatial navigation and episodic memory: computational modelling and electrophysiological analysis of the function of hippocampal neurons in the rat, functional imaging of human navigation, and neuropsychological experiments on spatial and episodic memory.
2. Investigation of human short-term memory for serial order: computational modelling, functional imaging and psychological experiment.
"Functional implications of the stability and variability of place cell activity during behavior"
Our research takes a multidisciplinary approach to the problem of how animals process spatial information to navigate in space. Recent progress on the neurophysiological bases of spatial knowledge provides support for biologically realistic computational models inspired by the concepts of cognitive psychology. Accordingly, we study not only how animals perceive and navigate in space but also the involvement of several neural systems in these abilities.
Emphasis is put on the role of the hippocampus and several neocortical areas (parietal, prefrontal, retrosplenial, striate cortices) thought to subserve distinct functions in spatial processing. Lesion studies are aimed at describing the differential effects induced by damage of each area. Reversible inactivation studies allow us to address the specific phase of information processing for each system.
Our studies of unit activity in freely moving rats have demonstrated the existence of "place cells" in the ventral hippocampus. Recently, we showed that the control of dorsal hippocampal place cell firing is exerted by selective classes of spatial information stemming from the distal environment. We also demonstrated that blind rats have place cells very similar to normal rats. We are now investigating the nature of the coupling between the spatial firing of place cells and navigation performance to establish whether place cells participate in an important way in the calculation of paths.