Figure 6.

Subjects' decisions reflect evidence accumulated over the course of the trial. a, Schematic of average stimulus frequencies for trials supporting opposing decisions. Top, Trials were selected if their average stimulus rate from 0 to 700 ms was 10 Hz (seven events over 700 ms). Trials were then grouped according to whether the subject chose low (red) or high (blue) on each trial. Average stimulus rate within the bin of interest (700–1000 ms; dashed lines) was then compared for stimuli preceding left and right choices. Bottom, Same as in top panel except that the window of interest occurred early in the trial (0–300 ms). b, Solid traces indicate difference in average event rate for trials that preceded left versus right choices for all time points in a trial. Color conventions are the same as in Figure 2, a and b. Thin lines indicate SEM computed via bootstrapping. Dashed traces indicate difference in average rate for trials assigned randomly to two groups. Data were pooled from six human subjects. Trial numbers differed slightly for each time point; ∼1800 trials were included at each point. c, Same as b but for an individual rat. Trial numbers differed slightly for each time point; ∼3200 trials were included at each point.