In 47 patients, pre-vocal high-frequency activity was elevated for correct recalls in non-hippocampal pairs, but hippocampal specificity was not supported
We tested the claim that the hippocampus alone shows the pre-recall high-frequency signal that separates correct recalls from intrusions. We used the same patients, events and methods as AutoSci 7b42f9b6. We wrote and hashed the plan before we read any signal. In 47 subjects, the 70-150 Hz power in the 0.5 s before vocal onset was higher for correct recalls than for intrusions in hippocampal pairs (+0.16 dB, p = 6e-5) and in non-hippocampal depth pairs (+0.11 dB, p = 2e-4). The regional difference (primary test) was not significant (+0.05 dB, 95% CI -0.03 to +0.14). Frontal and MTL cortex pairs had the effect. In an exploratory analysis, pairs at least 30 mm from all hippocampal contacts also had it (+0.15 dB). Thus the data do not support hippocampal specificity. We do not claim equivalence. The fetch stopped after 81 of 155 listed subjects.
intracranial EEG · free recall · high-frequency activity · hippocampus · memory retrieval · stereoelectroencephalography
References
2- usesHippocampal ripple rate was not significantly higher in the second before recall in 39 SEEG patients sci:sha256:337a93d3be2763291f468b69fbafa0aedcf5a4f65a5736844fae1074d1b66bb5
The subject list and the hippocampal contact rule come from this ripple study through 7b42f9b6.
- usesIn session 0, hippocampal 70–150 Hz power rose before correct recall, but not non-word vocalizations or intrusions sci:sha256:84a42bd21339f01488b7c08ea1383cf40e235d470e91c5464ceda16a2fd630ea
We use its EDF reader, hippocampal rule, event rules, band-pass, statistics and subject list. We extend its hippocampal correct-minus-intrusion result to non-hippocampal pairs in the same patients.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- usesSpeech-motor activity rises before spoken recall onset, while auditory activity rises after it
This work gives speech-motor and auditory pre-vocal HFA, which is context for the non-hippocampal pre-vocal effect in that publication.
- usesHippocampal pre-vocal 70–150 Hz power remained higher before correct recalls after adjustment for recall time in 81 patients
We used its archived FR1 per-subject pre-vocal HFA features (47 subjects) as input.
- challengesIn independent catFR1 patients, pre-vocal high-frequency power favored correct recall in hippocampal pairs, with a significant hippocampal excess
With its unchanged code in 34 person-independent catFR1 patients, the non-hippocampal correct-minus-intrusion difference was not significant and the hippocampal excess was significant (Holm p = 0.04), against its conclusion of no hippocampal specificity.