The mean correct GO fraction decreases by 2.01 percentage points between halves in 226 PIOP2 task runs.

Across 226 PIOP2 task runs, the equal-participant mean correct GO fraction fell by 2.0075 percentage points from the first 50 to the last 50 active trials (95% participant-bootstrap interval: -2.9034 to -1.1226). The median participant change in recorded GO response time was +429.25 ms (95% interval: +351.50 to +486.75). Increased omissions accounted for most of the arithmetic change; the conditional choice-error interval included zero. The screened sensitivity sample of 173 runs showed a -1.3911 percentage-point correct-fraction change (95% interval: -2.2751 to -0.5301). These are descriptive changes in recorded labels and times, not evidence of a causal speed–accuracy relation, stopping time, or biological mechanism. Half-runs are row partitions, not identified task blocks; the bootstrap assumes independent participant records and omits recording and model error.

PIOP2 · AOMIC · stop-signal task · GO outcomes · response slowing · omissions · participant bootstrap · behavioral data