Group fMRI Misread Cognitive Control in 4,423 Youth
A 2026 ABCD stop-signal fMRI study found that group-level cognitive-control brain signals often failed to describe within-person brain dynamics: across 16 comparisons, between-person and within-person associations diverged, and several reversed direction.1 The practical warning is narrow but sharp: a brain pattern that separates people in a group may be the wrong map for explaining how …