Figure 2. BF neurons with bursting responses to the go signal were inhibited nearly completely by the stop signal, irrespective of whether successful stopping was rewarded.

(a) (top) Responses of individual BF neurons collapsed across both SST variants (n=494) to the go signal, shown as the difference between go trials and foreperiod-matched controls. Individual BF neurons were sorted by the latency of the first significant response within 200ms of go signal onset. Black dotted lines separate neurons with significant inhibitory responses (n=21), excitatory responses (n=285), and no response (n=188) to the go signal. Bursting neurons were identified as BF neurons with an excitatory response within 200ms of go signal onset and a baseline firing rate less than 12 Hz (275/285) (red vertical bar). (bottom) Population PSTH (mean ± s.e.m.) for bursting neurons in go trials and foreperiod-matched controls, with significant excitation indicated by the red horizontal bar (Bonferroni-corrected paired t-test for each 10ms bin). (b) Responses of the same individual BF neurons to the stop signal, shown as the difference between stop trials and latency-matched go trial controls. The sorting order of BF neurons in the top panel is the same as in (a). The blue horizontal bar in the bottom panel indicates significant inhibition. Conventions are the same as in (a). (c) Scatter plot of the average firing rate in the [0.05, 0.2]s window after the go signal vs. baseline firing rate for individual BF neurons, and corresponding marginal distributions. (d) Scatter plot of the average firing rates in the [0.05, 0.2]s window after the go signal vs. in the [0.1, 0.5]s window after the stop signal for individual BF neurons, and corresponding marginal distributions. Bursting neurons are indicated in red, other neurons with significant responses to the go signal are indicated in black, and neurons with no significant responses are indicated in gray.