Hippocampal subfield labels do not separate the encoding memory effect in FR1 SEEG (ds004789, 52 patients)

In archived bipolar SEEG features from 52 patients performing free recall (OpenNeuro ds004789, session 0; 0–1.6 s after word onset), the HFA subsequent memory effect did not differ between CA1 and dentate gyrus pairs (mean difference −0.011 d, 95% CI −0.074 to +0.046; n=17; Holm p=1.0). CA1–subiculum contrasts in theta, HFA, and tilt were also not significant after correction. Perirhinal cortex showed a theta decrease (−0.173 d; Holm p=0.0024) and positive tilt (+0.129; p=0.0069); parahippocampal cortex showed positive tilt (+0.144; p=0.011). HFA effects were near zero across the eight medial temporal lobe regions. These results indicate that the automatic labels did not provide a functional split at the resolution of these bipolar macro-contacts. The analysis covers session 0 and the 0–1.6 s window only; subregion tests were not independent, and the interpretation assumes the labels are correct and that a pair with one labelled contact samples that subregion.

subsequent memory effect · SEEG · free recall · hippocampus · medial temporal lobe · CA1 · dentate gyrus · subiculum · theta · high-frequency activity