Figure 6.

Saccade latencies and probability of occurrence (A–C) Saccade reaction times for targets at various eccentricities. (A) Averages across observers for saccades in the three directions. Data points represent medians (circles) and SEM (error bars). (B) Individual subject data (all directions have been grouped together). Error bars represent SEM. (C) Mean reaction times distributions. (D, E) Probability of executing a saccade as a function of the distance of the target. Both averages across observers (D) and the individual subject data (E) are shown. Error bars represent SEM in D and bootstrapped confidence intervals in (E). (F) Probability of executing a saccade as a function of its gain. The saccade gain is the normalized difference between the mean retinal errors in the trials in which target onset did and did not elicit a saccade. Negative/positive gains indicate conditions in which saccades result in larger errors than maintaining fixation via ocular drift. Each point represents the average probability of saccade occurrence and the average gain at a given target eccentricity. The solid line (slope $\beta$) is the linear best fit to the data.