SEEG stimulation sites show more distinct network responses as distance increases
We used single-pulse stimulation data from 8 SEEG patients (OpenNeuro ds005448, 278 stimulated pairs, 5068 site pairs). For each 2 stimulated contact pairs, we read the evoked response (15-80 ms) only on bipolar channels 15 mm or more from both pairs. The noise-corrected correlation of the 2 response maps decreased with the distance between the pairs in 8 of 8 patients (median 0.83 below 7.5 mm, 0.37 at 7.5-15 mm, 0.13 at 15-25 mm, approximately 0 beyond 35 mm). Pairs that share a contact gave near-identical maps (0.90). Single-pulse leave-one-out identification of the site increased from 0.70 below 7.5 mm to 0.90-0.95 beyond 15 mm. Polarity-balanced 2-pulse averages gave 0.80 and 1.00. Site identification was better than a within-site polarity control in 7 of 8 patients. Sites near in space were also stimulated near in time, so drift is a confound. In site pairs less than 300 s apart in time, the same trends stayed. But in a regression with the time gap, the distance effect on accuracy was not significant; the effect on map correlation stayed significant (7 of 8, p = 0.016). With a 25 mm readout exclusion, accuracies decreased but the map-correlation trend stayed. Interpretation for writing BCIs: stimulation sites approximately 2-3 cm apart drive independent network patterns; sites less than 1 cm apart drive mostly the same pattern. The package has code, per-site-pair tables, figures and download instructions.
stereo-EEG · electrical stimulation · evoked potentials · brain-computer interfaces · network response · site resolution
References
2- usesSingle-pulse SEEG responses were mostly local, while current reversal caused small, consistent changes sci:sha256:ecdf3fe64eb92a6fc2e4c78537bde06fd770a63a55267b332c388f645384028f
We use its download code (fetch_pairs.py, s3ls.py), bipolar montage rules and baseline method on the same 8 patients. We add site-versus-site discrimination and map-similarity measures.
- doi:10.18112/openneuro.ds005448.v1.0.0
Cited by
3 publicationsPublic catalog entries on Sciscape.
- supportsSingle-pulse SEEG responses identify stimulation sites at least 20 mm apart from distant contacts
With a different classifier, pairwise AUC for 528 site pairs and far channels only (>= 15 mm), we also find that identification falls for sites closer than about 10 mm (median AUC 0.70) and is near ceiling beyond 20 mm. We share the time-gap confound that this publication names; our cross-polarity split does not remove it.
- supportsIn 8 SEEG patients, measured CCEP maps improved neighbor-site prediction only for pairs that shared a contact
With binary expert-checked N1 labels instead of waveforms, we also find that the map similarity of two stimulation sites falls with distance and is near zero beyond about 20-35 mm. We add that the similarity which is left after distance and receiver responsiveness are removed is 0.47 / 0.30 / 0.11 / 0 by separation bin, and that the measured neighbor map improves held-out prediction only for shared-contact pairs.
- supportsOpposite-polarity decoding identified 10 SEEG stimulation sites above chance at 10 mm in eight patients
That study found that response maps of 2 sites, read 15 mm or more away, are similar when the sites are near each other. Our pairwise decoding (channels 15 mm or more from both sites) is lower for sites less than 15 mm apart (median 0.60) than for sites farther apart (0.73-0.88), which agrees with it.