12-target SSVEP, dry and wet electrodes

Wearable SSVEP BCI dataset (dry and wet electrodes): EEG decoding results

An open wearable SSVEP dataset: 8-channel EEG from 102 healthy participants performing a cue-guided 12-target SSVEP task (9.25–14.75 Hz), recorded with wet and with dry electrodes, 10 consecutive blocks each. Participants were recruited through the BCI Brain-Controlled Robot Contest at the 2020 World Robot Contest. Released by Zhu et al. in Sensors (2021), with data on figshare.

Also known as Wearable SSVEP BCI Dataset · An Open Dataset for Wearable SSVEP-Based Brain-Computer Interfaces · figshare 13560281 · Zhu et al. (2021)

Description sources figshare.com · pmc.ncbi.nlm.nih.gov · doi.org · bci.med.tsinghua.edu.cn

Where it appears

Published results

Each figure comes from the reviewed download linked in its group. One row is above another only where their 95% intervals do not overlap.

Dry vs. wet sensor transfer

Source page: Dry vs. wet electrodes · deployment-topics.json

Uniform random · Wet recording · no source training
8.6% (8.1%–9.1%)
Uniform random · Dry recording · no source training
8.1% (7.6%–8.6%)
Same-frequency power · Wet recording · no source training
39.8% (35.4%–44.3%)
Same-frequency power · Dry recording · no source training
36.0% (31.8%–40.2%)
CCA · Wet recording · no source training
81.6% (77.7%–85.1%)
CCA · Dry recording · no source training
65.5% (60.6%–70.2%)
FBCCA · Wet recording · no source training
82.3% (78.7%–85.7%)
FBCCA · Dry recording · no source training
64.6% (59.5%–69.6%)
Spectral ridge · Trained on wet, tested on wet
40.3% (36.5%–44.3%)
Spectral ridge · Trained on wet, tested on dry
35.2% (31.8%–38.8%)
Spectral ridge · Trained on dry, tested on dry
37.2% (33.5%–41.0%)
Spectral ridge · Trained on dry, tested on wet
39.7% (35.9%–43.6%)
EEGNet · Trained on wet, tested on wet
75.0% (70.3%–79.5%)
EEGNet · Trained on wet, tested on dry
45.6% (40.5%–50.8%)
EEGNet · Trained on dry, tested on wet
64.0% (59.1%–68.8%)
EEGNet · Trained on dry, tested on dry
56.8% (51.9%–61.6%)
Balanced accuracy, 16 configurations. Dot: the estimate; line: 95% interval; dashed line, where drawn: chance level.
MethodConditionMetricValuePeople
Uniform randomcomparatorWet recording · no source trainingBalanced accuracy8.6%8.1%–9.1%102
Uniform randomcomparatorDry recording · no source trainingBalanced accuracy8.1%7.6%–8.6%102
Same-frequency powercomparatorWet recording · no source trainingBalanced accuracy39.8%35.4%–44.3%102
Same-frequency powercomparatorDry recording · no source trainingBalanced accuracy36.0%31.8%–40.2%102
CCAWet recording · no source trainingBalanced accuracy81.6%77.7%–85.1%102
CCADry recording · no source trainingBalanced accuracy65.5%60.6%–70.2%102
FBCCAWet recording · no source trainingBalanced accuracy82.3%78.7%–85.7%Five Butterworth order-4 sub-bands (6–80 to 38–80 Hz), four harmonics102
FBCCADry recording · no source trainingBalanced accuracy64.6%59.5%–69.6%Five Butterworth order-4 sub-bands (6–80 to 38–80 Hz), four harmonics102
Spectral ridgeTrained on wet, tested on wetBalanced accuracy40.3%36.5%–44.3%102
Spectral ridgeTrained on wet, tested on dryBalanced accuracy35.2%31.8%–38.8%102
Spectral ridgeTrained on dry, tested on dryBalanced accuracy37.2%33.5%–41.0%102
Spectral ridgeTrained on dry, tested on wetBalanced accuracy39.7%35.9%–43.6%102
EEGNetTrained on wet, tested on wetBalanced accuracy75.0%70.3%–79.5%102
EEGNetTrained on wet, tested on dryBalanced accuracy45.6%40.5%–50.8%102
EEGNetTrained on dry, tested on wetBalanced accuracy64.0%59.1%–68.8%102
EEGNetTrained on dry, tested on dryBalanced accuracy56.8%51.9%–61.6%102

Calibration budget · spectral ridge

Source page: How much calibration? · deployment-topics.json

Spectral ridge · Source-only, trained on wet, tested on wet
39.2% (35.4%–43.0%)
Spectral ridge · Source-only, trained on wet, tested on dry
35.4% (32.0%–39.0%)
Spectral ridge · Source-only, trained on dry, tested on wet
39.0% (35.2%–42.9%)
Spectral ridge · Source-only, trained on dry, tested on dry
37.2% (33.6%–40.9%)
Spectral ridge · 12 calibration trials · wet
15.3% (13.7%–17.1%)
Spectral ridge · 24 calibration trials · wet
18.2% (15.9%–20.7%)
Spectral ridge · 48 calibration trials · wet
21.3% (18.3%–24.5%)
Spectral ridge · 12 calibration trials · dry
15.0% (13.6%–16.5%)
Spectral ridge · 24 calibration trials · dry
18.3% (16.3%–20.7%)
Spectral ridge · 48 calibration trials · dry
21.8% (19.3%–24.5%)
Balanced accuracy, 10 configurations. Dot: the estimate; line: 95% interval; dashed line, where drawn: chance level.
MethodConditionMetricValuePeople
Spectral ridgeSource-only, trained on wet, tested on wetBalanced accuracy39.2%35.4%–43.0%102
Spectral ridgeSource-only, trained on wet, tested on dryBalanced accuracy35.4%32.0%–39.0%102
Spectral ridgeSource-only, trained on dry, tested on wetBalanced accuracy39.0%35.2%–42.9%102
Spectral ridgeSource-only, trained on dry, tested on dryBalanced accuracy37.2%33.6%–40.9%102
Spectral ridge12 calibration trials · wetBalanced accuracy15.3%13.7%–17.1%102
Spectral ridge24 calibration trials · wetBalanced accuracy18.2%15.9%–20.7%102
Spectral ridge48 calibration trials · wetBalanced accuracy21.3%18.3%–24.5%102
Spectral ridge12 calibration trials · dryBalanced accuracy15.0%13.6%–16.5%102
Spectral ridge24 calibration trials · dryBalanced accuracy18.3%16.3%–20.7%102
Spectral ridge48 calibration trials · dryBalanced accuracy21.8%19.3%–24.5%102

Calibration budget · eTRCA and CCA

Source page: How much calibration? · deployment-topics.json

CCA · No calibration · dry
65.1% (60.0%–70.0%)
CCA · No calibration · wet
81.1% (77.2%–84.8%)
Single-band eTRCA · 24 calibration trials · dry
12.4% (10.4%–15.0%)
Single-band eTRCA · 24 calibration trials · wet
39.8% (34.1%–45.8%)
Single-band eTRCA · 48 calibration trials · dry
15.1% (12.6%–18.2%)
Single-band eTRCA · 48 calibration trials · wet
64.0% (57.1%–70.7%)
Balanced accuracy, 6 configurations. Dot: the estimate; line: 95% interval; dashed line, where drawn: chance level.
MethodConditionMetricValuePeople
CCANo calibration · dryBalanced accuracy65.1%60.0%–70.0%102
CCANo calibration · wetBalanced accuracy81.1%77.2%–84.8%102
Single-band eTRCA24 calibration trials · dryBalanced accuracy12.4%10.4%–15.0%102
Single-band eTRCA24 calibration trials · wetBalanced accuracy39.8%34.1%–45.8%102
Single-band eTRCA48 calibration trials · dryBalanced accuracy15.1%12.6%–18.2%102
Single-band eTRCA48 calibration trials · wetBalanced accuracy64.0%57.1%–70.7%102

New SSVEP frequencies · CCA with a learned correction, trained on BETA and run unchanged

Source page: New SSVEP frequencies · Chance level 8.33% · new-ssvep-frequencies-update.json

MethodConditionMetricValuePeople
CCA with learned correctionDry electrodes · trained on BETA, run unchangedAccuracy65.45%60.82%–70.08%102
Matched CCAcomparatorDry electrodes · no trainingAccuracy65.38%60.73%–70.06%102
CCA with learned correctionDry electrodes · CCA with learned correction minus matched CCA, the same people and windows (primary contrast)Paired difference, accuracy+0.07 pp−0.71–+0.91 ppThe interval includes zero.102
Cropped-spectrum check (Wearable-102)comparatorDry electrodes · no training, a diagnostic onlyAccuracy57.78%52.79%–62.89%102
CCA with learned correctionWet electrodes · trained on BETA, run unchangedAccuracy81.04%77.14%–84.49%102
Matched CCAcomparatorWet electrodes · no trainingAccuracy81.65%77.60%–85.14%102
CCA with learned correctionWet electrodes · CCA with learned correction minus matched CCA, the same people and windows (primary contrast)Paired difference, accuracy−0.61 pp−1.48–+0.23 ppThe interval includes zero.102
Cropped-spectrum check (Wearable-102)comparatorWet electrodes · no training, a diagnostic onlyAccuracy73.01%68.46%–77.18%102
CCA with learned correctionBoth sensors · trained on BETA, run unchangedAccuracy73.24%69.40%–76.88%102
Matched CCAcomparatorBoth sensors · no trainingAccuracy73.51%69.71%–77.22%102
CCA with learned correctionBoth sensors · CCA with learned correction minus matched CCA, the same people and windows (secondary contrast)Paired difference, accuracy−0.27 pp−0.95–+0.40 ppThe interval includes zero.102
Cropped-spectrum check (Wearable-102)comparatorBoth sensors · no training, a diagnostic onlyAccuracy65.40%60.94%–69.69%102

The 105 models are CCA with a learned correction, trained on BETA (7 participant folds × 5 frequency rotations × 3 training seeds), run with no retraining on 102 people’s recordings as stored: 12 targets, 12,240 two-second windows per sensor. Each person’s accuracy is averaged over the 105 models, then over people, with no ensemble or model choice. Both methods are given the 12 candidate frequencies. The model’s score is a scaled CCA correlation plus a bounded learned term, so its difference from matched CCA is what the learned term adds. Intervals: paired person bootstrap, 2,000 draws, conditional on the fixed 105 models and unadjusted for the two sensors.

Matched CCA uses sine and cosine references up to the third harmonic, as the models’ own CCA term does, and reached 65.38% dry and 81.65% wet; the dry-versus-wet page's CCA uses references up to the fourth harmonic on the same windows and reached 65.47% and 81.56%.

Wearable-102’s stored amplitude unit is undocumented and the correction reads amplitude spectra, so a unit effect is not separated from the change of dataset. Window onset, hardware, reference, people and frequency grid all change at once; no equivalence margin was tested, and no one-factor ablation or target adaptation was run, so no single cause is isolated. Dry and wet are the primary contrasts; both sensors together and the cropped-spectrum check are secondary, the check a diagnostic only. This is a different task on other recordings, so these scores do not compare with BETA’s held-out or seen tasks. Wearable-102 also appears on other pages of this site, and its documentation cannot rule out that some people also appear in BETA.

Source and licence

Wearable SSVEP BCI dataset (dry and wet electrodes)

Credit Zhu, F., Jiang, L., Dong, G., Gao, X., & Wang, Y. (2021). An Open Dataset for Wearable SSVEP-Based Brain-Computer Interfaces (Version 4) [Data set]. Figshare. https://doi.org/10.6084/m9.figshare.13560281.v4

CC BY 4.0 · Dataset record ↗ · doi.org ↗

BCI Report does not redistribute any recording. These are aggregate measurements computed by BCI Report under the licence above; the data remain their creators’.

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Cite this page

BCI Report (2026). Wearable SSVEP BCI dataset (dry and wet electrodes): EEG decoding results. https://bci.report/datasets/wearable-ssvep-102/

Figures from releases new-ssvep-frequencies-update-20261020 (2026-10-20), deployment-topics-20260920-v1 (2026-09-20). Cite the upstream dataset as well: its credit is on this page.

Every release is archived on Zenodo: doi:10.5281/zenodo.23123296. BibTeX for the site and its releases → · CITATION.cff ↗