Figure 8.

No systematic difference in eye movements between drug and baseline conditions. A, Fixation precision (see Materials and Methods) did not differ between conditions [median 0.49 degrees of visual angle squared (dva²) for both baseline and 5-HT application, respectively; median 0.49 dva² and 0.50 dva² for baseline and saline application, respectively; the change with drug application did not differ significantly between the saline and 5-HT experiments, p = 0.68]. B, Microsaccade amplitudes were similar between conditions (median 0.04 dva for baseline and serotonin application, respectively, n_5-HT = 206; median 0.04 dva for baseline and saline application, respectively, n_NaCl = 65) and their changes did not differ significantly for serotonin versus saline application (p = 0.43). C, Similarly, the frequency of microsaccades did not change between conditions (median, 3.4 s⁻¹ for baseline and serotonin application, respectively, n_5-HT = 206; median, 3.2 and 3.3 s⁻¹ for baseline and saline application, respectively), and the changes did not differ between conditions (p = 0.96; n_5-HT = 206, n_NaCl = 65, Wilcoxon rank-sum test for all comparisons). Note that for units for which several experiments were performed, only the first experiment was included. Symbols are the same as in Figure 1. Shading represents the type of experiment for which the modulation by drug application [serotonin (5HT) or saline (NaCl)] was quantified.