{"dataset":{"id":"132","dataset_id":"nm000129","name":"Liu2020 – BETA SSVEP benchmark dataset","description":"The BETA SSVEP benchmark dataset comprises 64-channel EEG recordings from 70 healthy subjects performing a 40-target cued-spelling brain-computer interface task using steady-state visual evoked potentials (SSVEP). Recorded in a naturalistic classroom environment with joint frequency and phase modulation stimuli, this dataset provides a realistic benchmark for SSVEP-BCI applications with frequencies ranging from 8.0 to 15.8 Hz and 3-second trial durations.","owner_user_id":19,"status":"active","github_repo":"nemarDatasets/nm000129","concept_doi":"10.82901/nemar.nm000129","latest_version_doi":"10.82901/nemar.nm000129.v1.0.2","created_at":"2026-03-06 21:32:45","updated_at":"2026-08-18 18:12:58","zenodo_concept_id":null,"is_sandbox":0,"visibility":"public","ezid_status":"public","enrichment_json":"{\n  \"version\": \"2.0\",\n  \"pipeline_stage\": \"validated\",\n  \"title\": \"Liu2020 – BETA SSVEP benchmark dataset\",\n  \"description\": \"The BETA SSVEP benchmark dataset comprises 64-channel EEG recordings from 70 healthy subjects performing a 40-target cued-spelling brain-computer interface task using steady-state visual evoked potentials (SSVEP). Recorded in a naturalistic classroom environment with joint frequency and phase modulation stimuli, this dataset provides a realistic benchmark for SSVEP-BCI applications with frequencies ranging from 8.0 to 15.8 Hz and 3-second trial durations.\",\n  \"methods_description\": \"EEG data were acquired using a Synamps2 amplifier (Neuroscan) with 64 channels in the international 10-10 system, referenced to Cz, at 1000 Hz sampling rate and downsampled to 250 Hz. Subjects completed 4 blocks of 40 trials each with 2-3 second stimulation duration (depending on BCI experience) plus 0.5 second visual cue. Stimuli employed joint frequency and phase modulation (JFPM) with frequencies from 8.0 to 15.8 Hz (0.2 Hz step) and initial phases from 0 to 19.5π (0.5π step) arranged in a 5×8 QWERTY virtual keyboard layout.\",\n  \"license\": \"Non-commercial research use\",\n  \"dataset_type\": \"derivative\",\n  \"authors\": {\n    \"Bingchuan Liu\": {},\n    \"Xiaoshan Huang\": {},\n    \"Yijun Wang\": {},\n    \"Xiaogang Chen\": {},\n    \"Xiaorong Gao\": {}\n  },\n  \"keywords\": [\n    {\n      \"term\": \"SSVEP\"\n    },\n    {\n      \"term\": \"Brain-Computer Interfaces\",\n      \"subject_scheme\": \"MeSH\",\n      \"value_uri\": \"http://id.nlm.nih.gov/mesh/D062207\"\n    },\n    {\n      \"term\": \"EEG\"\n    },\n    {\n      \"term\": \"benchmark dataset\"\n    },\n    {\n      \"term\": \"visual evoked potentials\"\n    },\n    {\n      \"term\": \"frequency modulation\"\n    },\n    {\n      \"term\": \"speller application\"\n    }\n  ],\n  \"related_identifiers\": [\n    {\n      \"identifier\": \"10.3389/fnins.2020.00627\",\n      \"identifier_type\": \"DOI\",\n      \"relation_type\": \"IsDerivedFrom\"\n    },\n    {\n      \"identifier\": \"https://github.com/nemarDatasets/nm000129\",\n      \"identifier_type\": \"URL\",\n      \"relation_type\": \"IsDescribedBy\"\n    },\n    {\n      \"identifier\": \"https://nemar.org/dataset/nm000129\",\n      \"identifier_type\": \"URL\",\n      \"relation_type\": \"IsDescribedBy\"\n    }\n  ],\n  \"funding_references\": [\n    {\n      \"funder_name\": \"National Key Research and Development Program of China\",\n      \"award_number\": \"2017YFB1002505\"\n    },\n    {\n      \"funder_name\": \"Strategic Priority Research Program of Chinese Academy of Sciences\",\n      \"award_number\": \"XDB32040200\"\n    },\n    {\n      \"funder_name\": \"Key Research and Development Program of Guangdong Province\",\n      \"award_number\": \"2018B030339001\"\n    },\n    {\n      \"funder_name\": \"National Natural Science Foundation of China\",\n      \"award_number\": \"61431007\"\n    }\n  ],\n  \"resource_type_general\": \"Dataset\",\n  \"resource_type_specific\": \"EEG Dataset\",\n  \"modalities\": [\n    \"eeg\"\n  ],\n  \"sizes\": [\n    \"8.3 GB (142 files)\"\n  ],\n  \"formats\": [\n    \".html\",\n    \".json\",\n    \".mat\",\n    \".md\",\n    \".set\",\n    \".tsv\",\n    \".yaml\",\n    \".yml\"\n  ],\n  \"source_hash\": \"665f8591f037dd8a87163d85b8260669bb16b9a4b3172edcc2737c4aafe69cc3\"\n}","last_activity_at":"2026-08-16 13:24:36","source":null,"source_id":null,"subject_count":70,"modalities":"eeg","age_min":10,"age_max":64,"file_size":8289033905,"total_files":853,"tasks":"ssvep","metadata_columns_error":null,"staleness_warn_stage":null,"staleness_admin_notified_at":null,"authors":"Bingchuan Liu, Xiaoshan Huang, Yijun Wang, Xiaogang Chen, Xiaorong Gao","license":"Non-commercial research use","readme":"[![DOI](https://img.shields.io/badge/DOI-10.82901%2Fnemar.nm000129-blue)](https://doi.org/10.82901/nemar.nm000129)\n\n# BETA SSVEP benchmark dataset\n\nBETA SSVEP benchmark dataset.\n\n## Dataset Overview\n\n- **Code**: Liu2020BETA\n- **Paradigm**: ssvep\n- **DOI**: 10.3389/fnins.2020.00627\n- **Subjects**: 70\n- **Sessions per subject**: 1\n- **Events**: 8.6=1, 8.8=2, 9=3, 9.2=4, 9.4=5, 9.6=6, 9.8=7, 10=8, 10.2=9, 10.4=10, 10.6=11, 10.8=12, 11=13, 11.2=14, 11.4=15, 11.6=16, 11.8=17, 12=18, 12.2=19, 12.4=20, 12.6=21, 12.8=22, 13=23, 13.2=24, 13.4=25, 13.6=26, 13.8=27, 14=28, 14.2=29, 14.4=30, 14.6=31, 14.8=32, 15=33, 15.2=34, 15.4=35, 15.6=36, 15.8=37, 8=38, 8.2=39, 8.4=40\n- **Trial interval**: [0, 3.0] s\n- **File format**: MAT\n\n## Acquisition\n\n- **Sampling rate**: 250.0 Hz\n- **Number of channels**: 64\n- **Channel types**: eeg=64\n- **Channel names**: Fp1, Fpz, Fp2, AF3, AF4, F7, F5, F3, F1, Fz, F2, F4, F6, F8, FT7, FC5, FC3, FC1, FCz, FC2, FC4, FC6, FT8, T7, C5, C3, C1, Cz, C2, C4, C6, T8, M1, TP7, CP5, CP3, CP1, CPz, CP2, CP4, CP6, TP8, M2, P7, P5, P3, P1, Pz, P2, P4, P6, P8, PO7, PO5, PO3, POz, PO4, PO6, PO8, CB1, O1, Oz, O2, CB2\n- **Montage**: standard_1005\n- **Hardware**: Synamps2 (Neuroscan)\n- **Reference**: Cz\n- **Line frequency**: 50.0 Hz\n- **Impedance threshold**: 10 kOhm\n\n## Participants\n\n- **Number of subjects**: 70\n- **Health status**: healthy\n- **Age**: mean=25.14, std=7.97, min=9, max=64\n- **Gender distribution**: male=42, female=28\n- **BCI experience**: mixed\n\n## Experimental Protocol\n\n- **Paradigm**: ssvep\n- **Task type**: cued-spelling\n- **Number of classes**: 40\n- **Class labels**: 8.6, 8.8, 9, 9.2, 9.4, 9.6, 9.8, 10, 10.2, 10.4, 10.6, 10.8, 11, 11.2, 11.4, 11.6, 11.8, 12, 12.2, 12.4, 12.6, 12.8, 13, 13.2, 13.4, 13.6, 13.8, 14, 14.2, 14.4, 14.6, 14.8, 15, 15.2, 15.4, 15.6, 15.8, 8, 8.2, 8.4\n- **Trial duration**: 3.0 s\n- **Feedback type**: visual\n- **Stimulus type**: JFPM visual flicker\n- **Stimulus modalities**: visual\n- **Primary modality**: visual\n- **Synchronicity**: synchronous\n- **Mode**: offline\n- **Training/test split**: False\n\n## HED Event Annotations\n\nSchema: HED 8.4.0 | Browse: https://www.hedtags.org/hed-schema-browser\n\n```\n  8.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/8_6\n\n  8.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/8_8\n\n  9\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/9\n\n  9.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/9_2\n\n  9.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/9_4\n\n  9.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/9_6\n\n  9.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/9_8\n\n  10\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/10\n\n  10.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/10_2\n\n  10.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/10_4\n\n  10.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/10_6\n\n  10.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/10_8\n\n  11\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/11\n\n  11.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/11_2\n\n  11.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/11_4\n\n  11.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/11_6\n\n  11.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/11_8\n\n  12\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/12\n\n  12.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/12_2\n\n  12.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/12_4\n\n  12.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/12_6\n\n  12.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/12_8\n\n  13\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/13\n\n  13.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/13_2\n\n  13.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/13_4\n\n  13.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/13_6\n\n  13.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/13_8\n\n  14\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14\n\n  14.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_2\n\n  14.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_4\n\n  14.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_6\n\n  14.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_8\n\n  15\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15\n\n  15.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_2\n\n  15.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_4\n\n  15.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_6\n\n  15.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_8\n\n  8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/8\n\n  8.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/8_2\n\n  8.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/8_4\n\n```\n## Paradigm-Specific Parameters\n\n- **Detected paradigm**: ssvep\n- **Stimulus frequencies**: [8.0, 8.2, 8.4, 8.6, 8.8, 9.0, 9.2, 9.4, 9.6, 9.8, 10.0, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8, 12.0, 12.2, 12.4, 12.600000000000001, 12.8, 13.0, 13.2, 13.4, 13.600000000000001, 13.8, 14.0, 14.2, 14.4, 14.600000000000001, 14.8, 15.0, 15.2, 15.4, 15.600000000000001, 15.8] Hz\n- **Frequency resolution**: 0.2 Hz\n\n## Data Structure\n\n- **Trials**: 160\n- **Blocks per session**: 4\n\n## Preprocessing\n\n- **Data state**: epoched\n- **Notch filter**: 50 Hz\n- **Filter type**: zero-phase FIR\n- **Downsampled to**: 250.0 Hz\n\n## Signal Processing\n\n- **Classifiers**: TRCA, msTRCA, FBCCA, CCA\n- **Feature extraction**: CCA, TRCA, FBCCA\n- **Frequency bands**: bandpass=[3.0, 100.0] Hz\n- **Spatial filters**: CCA, TRCA\n\n## Cross-Validation\n\n- **Method**: leave-one-block-out\n- **Folds**: 4\n- **Evaluation type**: within_subject\n\n## BCI Application\n\n- **Applications**: speller\n- **Environment**: classroom\n- **Online feedback**: True\n\n## Tags\n\n- **Pathology**: healthy\n- **Modality**: visual\n- **Type**: perception\n\n## Documentation\n\n- **DOI**: 10.3389/fnins.2020.00627\n- **License**: Non-commercial research use\n- **Investigators**: Bingchuan Liu, Xiaoshan Huang, Yijun Wang, Xiaogang Chen, Xiaorong Gao\n- **Senior author**: Xiaorong Gao\n- **Institution**: Tsinghua University\n- **Department**: Department of Biomedical Engineering, Tsinghua University\n- **Country**: CN\n- **Repository**: Tsinghua BCI Lab\n- **Data URL**: http://bci.med.tsinghua.edu.cn/upload/liubingchuan/\n- **Publication year**: 2020\n- **Funding**: National Key Research and Development Program of China (No. 2017YFB1002505); Strategic Priority Research Program of Chinese Academy of Sciences (No. XDB32040200); Key Research and Development Program of Guangdong Province (No. 2018B030339001); National Natural Science Foundation of China (Grant No. 61431007)\n- **Ethics approval**: ","bids_version":"1.9.0","sessions_count":1,"publish_date":"2026-05-04 13:03:16","embedding_dirty":0,"license_tier":"noncommercial","zarr_status":"ready","zarr_converted_at":"2026-09-04 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