Chapter 6 - What are the Roles of Sensory and Parietal Activity in Visual Short-Term Memory?

Abstract

The widespread use of neuroimaging techniques has led to a rapid increase in our understanding of the neural mechanisms that support the maintenance of information in visual short-term memory (VSTM). Early findings suggested that VSTM is mediated by elevated, sustained, load-sensitive activity in regions of the intraparietal sulcus (IPS). These findings dovetailed nicely with the behavioral evidence that VSTM was limited by a fixed capacity of short-term storage “slots.” Recent evidence, however, has called into question both the behavioral models that describe VSTM performance, as well as the role of sustained, delay-period activity in the IPS. In this chapter, I review behavioral and neuroimaging evidence that VSTM may instead be supported by activity in sensory cortex, and that this activity is tied to the precision of VSTM representations. In light of these findings, alternative accounts of activity traditionally associated with VSTM maintenance are examined.