Statistical analyses

The p values reported in and referring to panels C and D of Figures 1​1–3 were determined by Mann–Whitney (run length) or two-tailed Student’s t tests, equal variance (velocity) comparing 0 to 10 min in the condition for either DMSO or propofol. The p values reported in panels E and F of Figures 1​1–3 were determined by Wilcoxon matched-pairs signed rank test (run length) or paired t test (velocity) comparing 0 to 10 min in the condition for either DMSO or propofol. The p values in Figure 4 were generated by one-way Brown–Forsythe analysis of variance (ANOVA) and Dunnett’s post-hoc analysis test. The p values for Figure 5 were generated by one-way ANOVA and Tukey’s post-hoc analysis.