Top-down modulation in visual working memory

Abstract

This chapter uses the vehicle of visuospatial representations to explore broader issues of the top down modulation of association cortex linked to activity in the prefrontal cortex (PFC). One general emerging view from brain imaging, neuropsychological studies, and from single cell recording is that the control and maintenance functions of working memory appear to be linked with PFC activity. This chapter offers both functional magnetic resonance imaging (fMRI) and event-related potential (ERP) data, demonstrating how the PFC might contribute to the inhibition of irrelevant visual information while focusing on and maintaining visual information that is relevant to the task in hand. Some of the recent work using transcranial magnetic stimulation (TMS) to induce temporary lesions offers a promising additional source of evidence for this form of top-down modulation of visual processing.