Abstract

Studies have implicated frontal and parietal cortical brain regions in the general performance of antisaccade tasks. Antisaccade task performance relies on one's ability to suppress a reflexive, sensory guided saccade made toward a cue in favor of a volitional saccade made away from a cue. However, this inhibitory process is brief in duration compared to other task demands such as prolonged fixation and the generation of saccades. To date, neuroimaging studies have only employed blocked designs which lack the requisite temporal resolution to identify brain regions specifically related to inhibition of reflexive saccades. With this issue in mind, the current study used an interleaved antisaccade paradigm optimized for event-related functional magnetic resonance imaging (fMRI). At the beginning of a trial, subjects were given an instruction that called for a prosaccade, antisaccade, or no-saccade on the occurrence of a suddenly appearing peripheral cue. Simultaneous monitoring of eye movements in the scanner allowed us to relate fMRI data with performance accuracy. Event-related fMRI methods were used to identify neural regions active during instruction, prestimulus preparation, and response phases. Preliminary analyses suggest that although the frontal, supplementary, and parietal eye fields were active at the time of response, the supplementary eye fields showed greater activity prior to the cue on trials in which a reflexive saccade was withheld. These data help clarify the different roles (e.g., motor, control, and perceptual) for the frontal, supplementary, and parietal eye fields during performance of the antisaccade task.

From: Curtis, C. E. and M. D'Esposito (2001). Event-related functional magnetic resonance imaging of antisaccade task performance. Cognitive Neuroscience Society, New York.