MTL activity patterns did not reliably distinguish repeated words in 16 SEEG subjects

In 16 subjects performing the RepFR1 repeated-word free-recall task, medial temporal lobe high-frequency activity patterns were not reliably more similar across presentations of the same word than across different words at the same list positions. The primary estimate was +0.011 Fisher z (95% CI -0.007 to +0.030; 7/16 subjects positive; Holm p = 0.39). The lag effect and recalled-word effect were also not supported. A registered temporal-context check detected adjacent-word pattern similarity (+0.023, 95% CI +0.006 to +0.046; p = 0.017). With 16 subjects, the estimated 80% detectable effect was about 0.024 Fisher z, so smaller item-specific effects are not excluded. The analysis used archived HFA features from OpenNeuro ds005411 version 1.0.1, session 0; it did not reprocess raw signals. The findings apply to one 0.10–0.75 s window, one frequency band, and mostly entorhinal and parahippocampal labels.

medial temporal lobe · high-frequency activity · SEEG · pattern similarity · free recall · repeated words · memory · temporal context