Cortico-thalamocortical operations of multi-target spatial working memory

Representation and manipulation of multiple target locations would be important aspects of spatial working memory [Tanaka 2002a, b]. It is, however, unknown how such processes are performed in the prefrontal cortical, corticocortical, and cortico-subcortical circuits. We here propose a model of the prefrontal cortical and cortico-thalamocortical circuits that represent and manipulate multiple targets. The simulation with this model shows that transient inputs to the thalamic relay cells increase the signal transmission of the thalamocortical afferents. This eliminates one or more of the targets represented in the prefrontal cortex. The number of the eliminated targets depends on the width of the directional tuning of the inputs to the relay cells.