Recorded zero delays increased the calculated trigger-failure parameter in 15 models of ds000030

This sensitivity analysis tested how stop-delay fields affect a calculated trigger-failure (TF) parameter when GO timing and stop-latency distributions stay fixed. It used all 126 CONTROL participants with available scanner STOP data from OpenNeuro ds000030 snapshot 1.0.0. The primary model used a gamma stop-latency distribution with shape 4 and mean 0.20 s. The fitted TF parameter was 0.19803089724201023 for recorded delays and 0.09139339810486773 for a hybrid field that replaced recorded zero with a positive planned delay. The difference was 0.1066374991371425 (10.66374991371425 percentage points). Recorded-minus-hybrid differences were positive in all 15 selected gamma models, from 3.3283296025518105 to 10.727380123440909 percentage points. A participant bootstrap gave a conditional 95% percentile interval of [0.08479570719051269, 0.13040175774093282] for the primary difference. This interval excludes uncertainty in GO fits, stop-law choice, recording policy, and actual tone onset. The result shows model sensitivity under fixed time distributions; it does not establish a biological TF rate. The study did not verify whether a stop tone began after an early response, validate model assumptions, or test full model accuracy.

trigger failure · stop-signal task · stop-signal delay · maximum likelihood · race model · sensitivity analysis · OpenNeuro · ds000030 · gamma distribution · lognormal distribution