Abstract

During an oculomotor delayed-saccade task, visual information about a target's location is used to later execute a memory-guiding saccade. The evolution of this sensory to motor transformation involves selection processes, whose timing relative to the retention interval critically influences the nature of maintained representations. Here, we investigate how maintenance and selection processes interact in the frontal eye fields (FEF) with fMRI. Four locations were sequentially cued for maintenance over a delay interval (delay 1). Then, an arrow appeared instructing the subject to select one target among the four cued locations. No saccades were made at this point. Instead, the selected location was the goal of a saccade made after another long delay (delay 2). The FEF responded robustly at a point time-locked to the selection event. This suggests a role in selecting the target from among the internal representations of the cued locations and/or the conversion of retrospective sensory codes into a prospective motor code. Moreover, significant FEF activity was found during the delay intervals preceding and following target selection. The mechanisms by which the FEF support working memory, therefore, are related to the selection, rehearsal, and maintenance of saccade goals.

From: Curtis, C., D'Esposito, M. (2004). Selection and maintainence of saccade goals in the human frontal eye fields. Society for Neuroscience, San Diego.