Inhibition of return: Neural basis and function

A goal of neuropsychology is to connect cognitive functions with underlying neural systems. Posner (in press) has proposed a framework for doing so in which elementary mental operations in cognitive models are expressed in terms of component facilitations and inhibitions in the performance domain. These components are in turn linked to underlying neural systems. In the area of spatial attention one such component is the tendency to inhibit orienting toward visual locations which have been previously attended (inhibition of return). The current studies use patients and normals to demonstrate the relationship of this component to systems which generate saccades. These mid-brain systems appear to contribute specific components to the generation of programs for visual attention. The deficits found in patients and the conditions under which the inhibition is found in normals suggest that inhibition of return may function to favor foveation of information at new locations.