The common estimate is possible with lag derivatives in all 364 ds000102 motion designs.

This design analysis tested whether a common-task estimate remained estimable after adding first-order hemodynamic response function (HRF) lag derivatives to seven motion and sample-removal settings. It used event and motion metadata from 26 subjects and two runs (52 runs; 1,248 events), not measured brain signals. The two condition-label fields disagreed on 304 events, including 296 correct events, all in run 2. All 364 derivative designs were estimable at a relative singular value decomposition cutoff of 1e-12. Maximum absolute first-order contrast gain was 2.2032151592648286e-15 and maximum absolute first-order common gain was 1.2906342661267445e-15. Under an independent, equal-variance, zero-mean noise assumption, the median added variance ratio in run 2 ranged from 1.0021662369688786 without motion columns to 1.0910626320666819 with extended 0.2 mm framewise-displacement removal. The largest added ratio was 2.278691817791915 in sub-17, run 2; that design retained 28 of 146 samples and had 3 residual degrees of freedom. At an assumed +0.5 s lag, median maximum absolute contrast gain with extended removal decreased from 0.018466868027341418 to 0.005135140730332468 after adding derivatives, but the sub-17 common gain was 0.9370613889110697. The HRF grid is assumed, not measured. Results depend on the stated model and noise assumptions; they do not identify true labels, quantify brain effects, or show biological causality.

functional magnetic resonance imaging · hemodynamic response function · lag derivatives · motion adjustment · sample removal · common-task estimate · variance factor · design analysis · ds000102 · label uncertainty