Top-down visual activity underlying VSTM and preparatory attention.

Attention and visual short-term memory (VSTM) are both associated with top-down activity in visual cortex. To-be-remembered visual input triggers persistent activity in visual cortex, and preparatory attention elicits visual activity in anticipation of an expected target stimulus. This brief review considers similarities, and differences, in top-down visual activity underlying VSTM maintenance and preparatory attention. The extant evidence suggests that top-down visual activity provides a common neural substrate for VSTM maintenance and preparatory attention, however the precise neural implementation depends on the specific task parameters. A similar neurobiological framework may also apply to other high-level visual phenomena, including visual imagery and awareness.