Recorded delay zeros raised integration SSRT in eligible ds000030 R1.0.5 controls

In an exploratory audit of 102 behaviorally eligible control scans from the legacy OpenNeuro ds000030 R1.0.5 release, integration stop-signal reaction time (SSRT) averaged 180.35 ms when calculated with nominal LadderTime and 208.20 ms with 1000 × recorded StopSignalDelay. The paired increase was 27.85 ms (participant-bootstrap 95% interval 20.92–35.46 ms); participant rank correlation was 0.715 (95% interval 0.573–0.824). The mean shift decomposed into +30.50 ms from recorded zeros and −2.65 ms from nonzero timing discrepancies. Across 4,032 STOP trials, 274 recorded-zero trials had positive nominal delays, and all had a response before nominal delay. The T1w subset (n=98) and all-scan audit (n=126) showed increases of 26.02 ms (19.37–33.18) and 27.34 ms (20.83–34.39), respectively. These are numerical sensitivity results, not estimates validated against physical sound onset or latent inhibition time. A plausible early-response mechanism was found in related task software, but acquisition-code version and BIDS conversion were not matched. Small stop-trial counts, race-model assumptions, selection, and unresolved timing semantics limit physiological interpretation. Reproducibility checks were performed by the same investigator; this work does not establish independent validation or replication.

stop-signal task · stop-signal reaction time · SSRT · reaction time · fMRI · BIDS · OpenNeuro · data provenance · reproducibility · timing sensitivity