In primates, the pulvinar is the largest nucleus in the thalamus. It is closely interconnected with many areas of visual cortex, the temporal lobe and the pariental lobe, as well as with the superior colliculus. The pulvinar may play a crucial role in recovery of vision following blindness of central origin, and it has been implicated in the effects of stroke in man. It is thought to play an important role in the central processing of visual information and in the integration of eye movements with visual perception. The nature of that role is not understood. This research is part of a long-term project to understand how the pulvinar contributes to vision. The proposed research is expected to clarify the functional significance of the tectopulvinar pathway, and to clarify the different functional relationships between striate and extrastriate cortex and two pulvinar subdivisions, the inferior and lateral nuclei.
One aim i s to find out how eye movements affect the visual responsifeness of single neurons in the pulvinar. Microelectrode recordings will be made from the pulvinar in macaques trained to make eye movements of specified size and direction. Since any effects of eye movements are likely to be mediated by input to the pulvinar from the superior colliculus, these effects will also be measured after colliculus ablation.
A second aim i s to investigate the degree to which the state of directed attention and the behavioral training techniques, affect the visual responsiveness of inferior and lateral pulvinar neurons.
