Figure 2.

Adaptive stop signal task and contextual SSD statistics. A, Anticipatory stop signal task. Top, On Go trials, subjects were instructed to press a key when the ascending bar crossed a target line, always occurring on 520 ms after trial onset. Feedback was given informing the subject if their response was earlier or later than the Go target (maximum 100 points). Bottom, On Stop trials, the bar stopped and turned red before reaching the target line. If no response was made (correct), the subject received a bonus of 200 points. Failure to inhibit the key press resulted in a −100 point penalty. B, Stop signal statistics across contexts. Distributions show the sampling distributions for SSDs on context trials in the Early (blue), Uniform (gray), and Late (purple) groups. Early and Late SSDs were normally distributed (parameters stated as in-figure text, N(μ, σ)). Below the distributions, each row of tick marks indicates the context SSDs for a single example subject in each group. Bottom row of red tick marks indicates the five probe SSDs included for all subjects regardless of context.