Preserved cue-state recruitment but prolonged preparatory activity in developmental dyscalculia

An advance cue allows a child to establish a task rule before a target appears. We tested whether developmental dyscalculia (DD) alters the recruitment or temporal regulation of this preparatory state. Cue-locked EEG was recorded from 143 children aged 6.4-12.0 years during a conditional numerical Go/No-Go task; the primary analysis included 138 children after exclusion of five records with discrepant age information. All between-group analyses used the same 19 homologous scalp channels. A diagnosis-blind, cross-validated scalp-state template was used to track cue-related preparation in held-out children. Both groups expressed a broad posterior-positive preparation pattern, and their expression-weighted maps were highly similar, r(19) = .964. No reliable group difference was detected before the cue or during the early cue period. A single DD > TD cluster emerged from 448 to 798 ms (permutation p < .001), extending to the end of the analyzed epoch. DD showed a later temporal centroid and peak, a longer effective span, and a larger fraction of state expression after 500 ms, whereas state onset and maximum pre-peak growth did not differ. The DD scalp pattern also carried greater central-parietal midline weight. Age did not moderate the group effect, and cue-state timing did not explain individual task performance beyond diagnosis and covariates. These findings indicate preserved recruitment but prolonged late expression of a cue-related preparatory state in DD, consistent with altered temporal regulation of preparation rather than failed cue detection or rule recruitment.