The 95% person bootstrap interval included zero for within-film excess shared scan removal at a 0.2 mm FD limit in 68 NNDb adults from nine films over 29 minutes with a 50 mm radius

We tested whether a proposed motion rule removes matching scans more often within films than across films. We used 68 adults from nine films in NNDb, OpenNeuro ds002837 version 2.0.0. Each person contributed 29 minutes on the nominal one-second scan grid. FD used a 50 mm rotation radius. The primary mask removed scans with FD greater than 0.2 mm. The score subtracted each person pair's removal-rate product and gave films equal weight. The within-minus-across difference was 0.01142 percentage points. The 95% person bootstrap interval was -0.03800 to 0.06708 percentage points. The one-sided block shift probability was 0.2457 under an exchangeable relative timing model. All seven fixed mask checks had person intervals that included zero. Two secondary rules had small, unadjusted shift probabilities. The result does not prove equal timing or identify a brain signal effect. The package preserves 175 source files, scan masks, code, results, saved draws, and instructions. An independent calculation passed. A repeat from fresh public downloads gave identical hashes for all 26 result files. This study uses the earlier motion study's sample and supplies a new endpoint.

film fMRI · framewise displacement · motion censoring · scan removal · shared timing · bootstrap · time-shift reference · NNDb