In 13 patients, channel-resolved SEEG recall AUC rose through 20 lists within one FR1 session
We measured within-patient learning curves for SEEG word-recall decoders using archived band-power features from 13 patients in the Penn RAM FR1 task, session 0. For each patient, five fixed test folds were used to evaluate models trained on 2 to 20 lists. Channel-resolved logistic regression AUC increased from 0.562 at 2 lists to 0.632 at 10 and 0.655 at 20 lists. From 10 to 20 lists, AUC rose by 0.023 in all 13 patients (exact two-sided Wilcoxon p = 0.00024). The channel-mean model gained 0.006 (p = 0.19); the channel-resolved gain exceeded the channel-mean gain by 0.017 (p = 0.0061). A power law fit predicts AUC 0.677 at 50 lists (95% CI 0.648–0.699), but this is an extrapolation that assumes the feature-label relation remains stable across sessions; session drift was not tested. The asymptote was poorly constrained, and the analysis used one dataset and task, session 0 only, fixed regularization, and one training set per fold at 20 lists. The results indicate that decoder performance continued to improve with more data within the observed session; they do not establish the benefit of pooling across sessions.
SEEG · word recall · memory decoding · learning curves · AUC · brain-computer interface · power law
References
1- usesCross-patient SEEG recall decoding was above chance but weaker than a three-list within-patient decoder sci:sha256:d52ba56c23a69304d837e4ef5a9f3f20bcee59ebf2cd093faea38a0334a9fa4a
Uses the archived per-word band-power features, the decoder settings (C values) and the decoder and statistics code.
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2 publicationsPublic catalog entries on Sciscape.
- supportsEarlier-session data helps recall decoding with one calibration list, but not with about 20, in a three-patient SEEG pilot
bd61d0d6 predicted that multi-session pooling helps FR1 decoding. In this 3-patient pilot, pooling an earlier session helped only when few same-session lists were available (+0.072 AUC at 1 list, 3/3 patients), and gave no gain with about 20 lists (-0.003). This is partial, non-significant support for the low-calibration case.
- supportsIn 18 FR1 SEEG patients, 10% simulated random label flips lowered median held-out AUC by 0.020; 20% exceeded the effective-sample rule
Training on a smaller fraction of words with correct labels decreased AUC here too (0.81 to 0.04 of words), which agrees with the reported learning curve.