Open-loop encoding stimulation did not decrease temporal contiguity of free recall
We tested whether open-loop 50 Hz stimulation through SEEG depth contacts during word encoding altered temporal contiguity in free recall. We analyzed behavioral events from OpenNeuro FR2 (ds005489 v1.0.3) and categorized free recall (catFR2; ds005491 v1.0.0), using subject-level temporal-factor scores. In FR2 depth-anode subjects, the stimulation-minus-no-stimulation difference was +0.018 (N=22; 95% CI -0.008 to +0.042; sign-flip p=0.18), with no detected decrease. The interval excludes a decrease greater than 0.008 TF units, about 4% of the observed above-chance contiguity. Stimulus-state clustering was not detected. The catFR2 estimate agreed in direction of uncertainty (-0.025, N=10; 95% CI -0.082 to +0.026). A lower backward lag -1 transition probability in FR2 was uncorrected, did not survive correction across six lags, and did not replicate in catFR2. The analysis used behavioral events only; no neural signals or stimulation responses were measured. The sample was small, the no-stimulation condition had only five lists per session, and the catFR2 replication was not fully independent. These findings do not support a temporal-context disruption account at this sample size for open-loop fixed-parameter stimulation.
free recall · temporal contiguity · temporal factor · memory · open-loop stimulation · SEEG · FR2 · catFR2
References
3- uses50 Hz open-loop depth stimulation during word encoding decreased later recall in ds005489; surface stimulation showed no effect sci:sha256:4636af3ff0cc862353979c5b008d8dee3803276e9ab70b7bea23c76a9bba0bf0
We used the per-word tables of this publication (ds005489_words.tsv.gz, ds005491_words.tsv.gz) to get the anode type (depth, grid, strip) and anode region of each stimulation list. We used its depth-anode subject set as the primary set. Our result extends its recall-rate result: the small recall decrease occurs without a detectable change in temporal contiguity.
- usesdoi:10.18112/openneuro.ds005489.v1.0.3
Behavioral event files from FR2 dataset ds005489 v1.0.3 were analyzed.
- usesdoi:10.18112/openneuro.ds005491.v1.0.0
Behavioral event files from catFR2 dataset ds005491 v1.0.0 were analyzed.
Cited by
2 publicationsPublic catalog entries on Sciscape.
- supportsOpen-loop 50 Hz encoding stimulation through depth anodes decreased correct recall but did not increase recall intrusions
It found that temporal contiguity did not change under FR2 stimulation. We found that intrusions also did not change. Both show that recall organization stayed the same while recall amount decreased.
- usesIn RAM FR2 depth-anode data, encoding stimulation did not measurably delay recalled words
Word table (anode type per session) and S3 events manifests of ds005489 and ds005491.