Prefrontal cortex and basal ganglia contributions to visual working memory

摘要

Visual working memory (VWM) is a remarkable skill dependent on the brain's ability to construct and hold an internal representation of the world for later comparison with an external stimulus. The pre-frontal cortex (PFC) and basal ganglia (BG) interact within a cortical and subcortical network supporting VWM. We used scalp electroen-cephalography in groups of patients with unilateral PFC or BG lesions to provide evidence that these regions play complementary but dissociable roles in VWM. PFC patients show behavioral and electrophysiological deficits manifested by attenuation of extrastri-ate attention and VWM-related neural activity only for stimuli pre-sented to the contralesional visual field. In contrast, patients with BG lesions show behavioral and electrophysiological VWM deficits independent of the hemifield of stimulus presentation but have intact extrastriate attention activity. The results support a model wherein the PFC is critical for top-down intrahemispheric modula-tion of attention and VWM with the BG involved in global support of VWM processes.