The mean stop time has no finite upper limit in 226 independent AOMIC PIOP2 race models with finite go support and positive hidden tail mass

We tested known finite go laws and fixed delay supports from all 226 AOMIC PIOP2 stop-signal records in OpenNeuro ds002790 version 2.0.0. In each independent race model, two chosen finite stop laws had exactly the same full recorded response law. Their mean stop times differed by 1000 ms. A third law used a 10% trigger failure atom and had the same recorded law. A proof shows that positive mass beyond the last observable comparison leaves the finite mean without a finite upper limit. The full law identifies cell masses, which give sharp limits for a capped mean. At a 500 ms cap, the median example range width was 1.620 ms. These are ideal model limits, not human estimates or confidence intervals. The package preserves exact proofs, a general audit tool, all source bytes and hashes, response laws, endpoint witnesses, independent checks, and a complete repeat calculation.

stop-signal task · race model · partial identification · capped mean · trigger failure · structural ambiguity · AOMIC-PIOP2 · OpenNeuro