70–150 Hz SEEG activity after response movement did not add error-detection information to a behavior-only model in 7 patients

We tested if high-gamma SEEG activity (70-150 Hz) can identify error trials in a perceptual decision task without outcome feedback. A BCI can use such a signal as an undo command. We used archived window features from 7 patients and a pre-registered plan. A shrinkage LDA with all bipolar channels and 5 time-ordered folds did not improve on a model with only behavior covariates (stimulus value, response time, trial index, chosen side). Mean dAUC was -0.062 in the window 0-0.5 s after movement onset; 2 of 7 patients were positive; the exact sign-flip p was 0.96. HGA alone gave mean AUC 0.505. No 200-ms bin from -1 s to +1 s gave a positive mean dAUC. The result applies to linear decoders on all channels with few error trials (31-75). It does not exclude low-frequency error signals or decoders with channel selection.

SEEG · high-gamma activity · error detection · brain-computer interface · linear discriminant analysis · perceptual decision-making · OpenNeuro