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

12-target SSVEP, dry and wet electrodes

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](https://figshare.com/articles/dataset/_/13560281) · [pmc.ncbi.nlm.nih.gov](https://pmc.ncbi.nlm.nih.gov/articles/PMC7916479/) · [doi.org](https://doi.org/10.3390/s21041256) · [bci.med.tsinghua.edu.cn](https://bci.med.tsinghua.edu.cn/download.html)

## Where it appears

- [Do dry EEG electrodes decode as well as wet ones?](https://bci.report/topics/dry-vs-wet/)
- [How much calibration data does a wearable SSVEP decoder need?](https://bci.report/topics/calibration-budget/)

## Published results

Every figure below is copied from a reviewed download, not recomputed for this page. Read each group with its protocol on the linked page.

### Dry vs. wet sensor transfer

Read with its protocol: [Dry vs. wet electrodes](https://bci.report/topics/dry-vs-wet/) · [deployment-topics.json](https://bci.report/data/deployment-topics.json)

**Balanced accuracy, 16 configurations.** Dot: the estimate; line: 95% interval; dashed line: chance level where the payload records one.

- 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%)

| Method | Condition | Metric | Value | People |
| --- | --- | --- | --- | --- |
| Uniform random — reference or comparator, not a decoding model | Wet recording · no source training | Balanced accuracy | 8.6% (8.1%–9.1%) | 102 |
| Uniform random — reference or comparator, not a decoding model | Dry recording · no source training | Balanced accuracy | 8.1% (7.6%–8.6%) | 102 |
| Same-frequency power — reference or comparator, not a decoding model | Wet recording · no source training | Balanced accuracy | 39.8% (35.4%–44.3%) | 102 |
| Same-frequency power — reference or comparator, not a decoding model | Dry recording · no source training | Balanced accuracy | 36.0% (31.8%–40.2%) | 102 |
| [CCA](https://bci.report/methods/cca/) | Wet recording · no source training | Balanced accuracy | 81.6% (77.7%–85.1%) | 102 |
| [CCA](https://bci.report/methods/cca/) | Dry recording · no source training | Balanced accuracy | 65.5% (60.6%–70.2%) | 102 |
| [FBCCA](https://bci.report/methods/fbcca/) | Wet recording · no source training | Balanced accuracy | 82.3% (78.7%–85.7%) | 102 |
| [FBCCA](https://bci.report/methods/fbcca/) | Dry recording · no source training | Balanced accuracy | 64.6% (59.5%–69.6%) | 102 |
| Spectral ridge | Trained on wet, tested on wet | Balanced accuracy | 40.3% (36.5%–44.3%) | 102 |
| Spectral ridge | Trained on wet, tested on dry | Balanced accuracy | 35.2% (31.8%–38.8%) | 102 |
| Spectral ridge | Trained on dry, tested on dry | Balanced accuracy | 37.2% (33.5%–41.0%) | 102 |
| Spectral ridge | Trained on dry, tested on wet | Balanced accuracy | 39.7% (35.9%–43.6%) | 102 |
| [EEGNet](https://bci.report/methods/eegnet/) | Trained on wet, tested on wet | Balanced accuracy | 75.0% (70.3%–79.5%) | 102 |
| [EEGNet](https://bci.report/methods/eegnet/) | Trained on wet, tested on dry | Balanced accuracy | 45.6% (40.5%–50.8%) | 102 |
| [EEGNet](https://bci.report/methods/eegnet/) | Trained on dry, tested on wet | Balanced accuracy | 64.0% (59.1%–68.8%) | 102 |
| [EEGNet](https://bci.report/methods/eegnet/) | Trained on dry, tested on dry | Balanced accuracy | 56.8% (51.9%–61.6%) | 102 |

### Calibration budget · spectral ridge

Read with its protocol: [How much calibration?](https://bci.report/topics/calibration-budget/) · [deployment-topics.json](https://bci.report/data/deployment-topics.json)

**Balanced accuracy, 10 configurations.** Dot: the estimate; line: 95% interval; dashed line: chance level where the payload records one.

- 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%)

| Method | Condition | Metric | Value | People |
| --- | --- | --- | --- | --- |
| Spectral ridge | Source-only, trained on wet, tested on wet | Balanced accuracy | 39.2% (35.4%–43.0%) | 102 |
| Spectral ridge | Source-only, trained on wet, tested on dry | Balanced accuracy | 35.4% (32.0%–39.0%) | 102 |
| Spectral ridge | Source-only, trained on dry, tested on wet | Balanced accuracy | 39.0% (35.2%–42.9%) | 102 |
| Spectral ridge | Source-only, trained on dry, tested on dry | Balanced accuracy | 37.2% (33.6%–40.9%) | 102 |
| Spectral ridge | 12 calibration trials · wet | Balanced accuracy | 15.3% (13.7%–17.1%) | 102 |
| Spectral ridge | 24 calibration trials · wet | Balanced accuracy | 18.2% (15.9%–20.7%) | 102 |
| Spectral ridge | 48 calibration trials · wet | Balanced accuracy | 21.3% (18.3%–24.5%) | 102 |
| Spectral ridge | 12 calibration trials · dry | Balanced accuracy | 15.0% (13.6%–16.5%) | 102 |
| Spectral ridge | 24 calibration trials · dry | Balanced accuracy | 18.3% (16.3%–20.7%) | 102 |
| Spectral ridge | 48 calibration trials · dry | Balanced accuracy | 21.8% (19.3%–24.5%) | 102 |

### Calibration budget · eTRCA and CCA

Read with its protocol: [How much calibration?](https://bci.report/topics/calibration-budget/) · [deployment-topics.json](https://bci.report/data/deployment-topics.json)

**Balanced accuracy, 6 configurations.** Dot: the estimate; line: 95% interval; dashed line: chance level where the payload records one.

- 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%)

| Method | Condition | Metric | Value | People |
| --- | --- | --- | --- | --- |
| [CCA](https://bci.report/methods/cca/) | No calibration · dry | Balanced accuracy | 65.1% (60.0%–70.0%) | 102 |
| [CCA](https://bci.report/methods/cca/) | No calibration · wet | Balanced accuracy | 81.1% (77.2%–84.8%) | 102 |
| [Single-band eTRCA](https://bci.report/methods/etrca/) | 24 calibration trials · dry | Balanced accuracy | 12.4% (10.4%–15.0%) | 102 |
| [Single-band eTRCA](https://bci.report/methods/etrca/) | 24 calibration trials · wet | Balanced accuracy | 39.8% (34.1%–45.8%) | 102 |
| [Single-band eTRCA](https://bci.report/methods/etrca/) | 48 calibration trials · dry | Balanced accuracy | 15.1% (12.6%–18.2%) | 102 |
| [Single-band eTRCA](https://bci.report/methods/etrca/) | 48 calibration trials · wet | Balanced accuracy | 64.0% (57.1%–70.7%) | 102 |

## 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 ↗](https://figshare.com/articles/dataset/An_Open_Dataset_for_Wearable_SSVEP-Based_Brain-Computer_Interfaces/13560281) · [doi.org ↗](https://doi.org/10.3390/s21041256)

BCI Report does not redistribute any recording. These are aggregate measurements computed by BCI Report under the licence above; the data belong to the people credited.

[All datasets →](https://bci.report/datasets/) · [All methods →](https://bci.report/methods/)

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Markdown copy of https://bci.report/datasets/wearable-ssvep-102/, generated from the published page. Figures are aggregate results; terms of use: https://bci.report/data-use/