Fig. 6.

Activity during the gap period for fixation neurons and buildup neurons. A, The thick solid lines represent the mean spike density on pro-saccade trials, and the dashed lines represent the mean spike density on anti-saccade trials. The vertical dashed line indicates the time of stimulus presentation. B, The mean discharge rate of individual fixation and buildup neurons at the end of the gap period on pro-saccade trials is plotted against the mean activity at the end of the gap period on anti-saccade trials (shaded area in A). One additional buildup neuron (115 spikes/sec pro-saccade activity and 175 spikes/sec anti-saccade activity) was not plotted in B. C, Change in neuronal activity during the gap period for individual buildup neurons and (D) fixation neurons. Dashed line, unity line (slope = 1). SE is the SEM discharge rate, averaged from the SEM computed in each bin (1 msec).