Pre-stimulus hippocampal theta and HFA did not predict later free recall in 49 patients

This independent reproduction tested whether hippocampal power in the 0.75 s before a word appeared predicted later free recall in OpenNeuro ds004789 FR1 session 0. Bipolar depth pairs were selected by hippocampal region labels, and word times used events.tsv sample/fs. The cohort comprised 54 subjects fetched before a stop time; 49 met inclusion criteria, contributing 385 pairs. After serial-position means were removed, pair-level Welch t values were averaged within subject and tested by a two-sided sign-flip permutation with Holm correction for theta (3–8 Hz) and high-frequency activity (HFA, 70–150 Hz, excluding 115–125 Hz). Neither pre-stimulus theta (mean t = −0.021, 95% bootstrap CI [−0.230, 0.184], Holm p = 0.85) nor HFA (mean t = −0.123, CI [−0.301, 0.065], Holm p = 0.39) predicted later recall. Post-onset HFA exceeded pre-onset HFA in 43 of 49 subjects, supporting the timing check. Exploratory post-onset theta was lower for recalled words (p = 0.014). The cohort overlaps with a prior analysis of the same dataset and session; this is a reproduction with a different pair rule and statistic, not a study of new patients. The source was fetched from the unversioned OpenNeuro S3 path, so the exact dataset release is uncertain. The 0.75 s windows provide 1.33 Hz spectral resolution and do not test theta below 3 Hz; mean t across pairs is not a calibrated effect size, and pairs within a subject are not independent.

hippocampus · free recall · subsequent memory · theta · high-frequency activity · intracranial EEG · reproduction · null result