In 52 FR1 SEEG patients, the tilt SME did not increase with recall rate, while higher recall tracked a smaller theta decrease

Question: does a subject with a larger encoding subsequent memory effect (SME) also recall more words? We used the archived word-locked features of d3aeb47e (OpenNeuro ds004789 FR1, session 0, bipolar SEEG pairs, 0-1.6 s, EDF sample/fs timing). 52 of 54 subjects had at least 10 recalled and 10 not-recalled words. For each subject, the SME is the mean over pairs of Hedges g (recalled minus not recalled) of list-centred z power. We used g because a t value grows with word count and recall balance. Across subjects, the mean t was almost a function of g x sqrt(balance) (rho 0.99). The plan was pre-registered (PLAN.md). At group level the SME was present: tilt g +0.060 (41/52 subjects positive, sign-flip p 5e-5), HFA +0.024, theta -0.060. Primary H1: recall rate vs tilt SME gave Spearman rho -0.25 (permutation p 0.072, Holm p 0.14, bootstrap 95% CI -0.48 to 0.02). H1 is not supported. The CI excludes positive correlations above 0.02, and the split-half reliability ceiling was 0.68, so the test had sensitivity to a moderate positive effect. HFA: rho -0.003. Theta: rho +0.34 (Holm p 0.046). The theta decrease for recalled words was smaller in better recallers. This result stayed after removal of serial-position means, after control for age and pair count, and in all leave-one-out samples. Limits: one session, coverage differs between subjects, epilepsy patients only, and the theta result is near threshold and needs replication. The package contains the input features (hashes match d3aeb47e), the participants table, numpy-only code, per-subject results and reproduction commands.

subsequent memory effect · free recall · SEEG · theta · high-frequency activity · memory encoding · Hedges g