Figure 2.

Saccade accuracy. (A) Saccade landing positions for targets at various distances ($7^{\prime }$-${80}^{\prime }$; different colors). Each panel shows data for one individual subject, with each dot representing one saccade. Black squares mark target locations. Data from different target angles are realigned along the vertical axis for better visualization. (B) Mean landing error ($S_E$). The average distance between saccade landing and target’s position is plotted as a function of target’s eccentricity ($T_E$). Error bars represent SEM. (C) Index of relative accuracy, defined as $1-S_E/T_E$. Error bars represent SEM. Panels B and C also show results obtained in a control experiment (squares), which relied on precise gaze localization to replicate the standard approach used for larger saccades (Fig. 1A). In this experiment, subjects (N=6) performed saccades toward targets at 20${}^{\prime }$ from an unstabilized fixation marker, but only trials with accurate fixation were selected for data analysis.