{"dataset":{"id":"130","dataset_id":"nm000127","name":"Kim2025 – 40-class beta-range SSVEP speller dataset","description":"A 40-class steady-state visually evoked potential (SSVEP) brain-computer interface speller dataset acquired from 40 healthy subjects using beta-range stimulation frequencies (14.0–21.8 Hz) to reduce visual fatigue. The dataset comprises 33-channel EEG recordings (31 scalp + 2 mastoid references) sampled at 1024 Hz across 6 sessions per subject, with 240 trials total using the joint frequency-phase modulation (JFPM) approach. This resource supports the development and benchmarking of low-fatigue BCI applications for communication interfaces.","owner_user_id":19,"status":"active","github_repo":"nemarDatasets/nm000127","concept_doi":"10.82901/nemar.nm000127","latest_version_doi":"10.82901/nemar.nm000127.v1.0.2","created_at":"2026-03-06 21:28:30","updated_at":"2026-08-18 18:12:54","zenodo_concept_id":null,"is_sandbox":0,"visibility":"public","ezid_status":"public","enrichment_json":"{\n  \"version\": \"2.0\",\n  \"pipeline_stage\": \"validated\",\n  \"title\": \"Kim2025 – 40-class beta-range SSVEP speller dataset\",\n  \"description\": \"A 40-class steady-state visually evoked potential (SSVEP) brain-computer interface speller dataset acquired from 40 healthy subjects using beta-range stimulation frequencies (14.0–21.8 Hz) to reduce visual fatigue. The dataset comprises 33-channel EEG recordings (31 scalp + 2 mastoid references) sampled at 1024 Hz across 6 sessions per subject, with 240 trials total using the joint frequency-phase modulation (JFPM) approach. This resource supports the development and benchmarking of low-fatigue BCI applications for communication interfaces.\",\n  \"methods_description\": \"EEG data were recorded from 40 healthy subjects (25 males, 15 females, aged 20–35 years) using a BioSemi ActiveTwo amplifier with 31 active scalp electrodes and 2 mastoid reference electrodes in standard 10-05 montage. Subjects performed a 40-target SSVEP speller task across 6 blocks of 40 trials each. Each trial consisted of 1.5 s rest, 0.5 s cue, and 5.0 s SSVEP stimulation at frequencies ranging from 14.0 to 21.8 Hz (0.2 Hz step) with 0.5π phase differences between adjacent stimuli using JFPM. Stimuli were presented in a 5×8 matrix on a 120 Hz monitor. EEG was recorded at 1024 Hz and epoched from −2000 to +5000 ms relative to stimulus onset.\",\n  \"license\": \"CC BY 4.0\",\n  \"dataset_type\": \"derivative\",\n  \"authors\": {\n    \"Heegyu Kim\": {},\n    \"Kyungho Won\": {},\n    \"Minkyu Ahn\": {\n      \"orcid\": \"0000-0001-6512-0167\"\n    },\n    \"Sung Chan Jun\": {\n      \"orcid\": \"0000-0001-5357-4436\"\n    }\n  },\n  \"keywords\": [\n    {\n      \"term\": \"SSVEP\"\n    },\n    {\n      \"term\": \"brain-computer interfaces\"\n    },\n    {\n      \"term\": \"EEG\"\n    },\n    {\n      \"term\": \"beta-range stimulation\"\n    },\n    {\n      \"term\": \"visual fatigue\"\n    },\n    {\n      \"term\": \"speller paradigm\"\n    },\n    {\n      \"term\": \"JFPM\"\n    }\n  ],\n  \"related_identifiers\": [\n    {\n      \"identifier\": \"10.1038/s41597-025-06032-2\",\n      \"identifier_type\": \"DOI\",\n      \"relation_type\": \"IsDerivedFrom\"\n    },\n    {\n      \"identifier\": \"10.6084/m9.figshare.28806815.v2\",\n      \"identifier_type\": \"DOI\",\n      \"relation_type\": \"References\"\n    },\n    {\n      \"identifier\": \"https://github.com/nemarDatasets/nm000127\",\n      \"identifier_type\": \"URL\",\n      \"relation_type\": \"IsDescribedBy\"\n    },\n    {\n      \"identifier\": \"https://nemar.org/dataset/nm000127\",\n      \"identifier_type\": \"URL\",\n      \"relation_type\": \"IsDescribedBy\"\n    }\n  ],\n  \"resource_type_general\": \"Dataset\",\n  \"resource_type_specific\": \"EEG Dataset\",\n  \"modalities\": [\n    \"eeg\"\n  ],\n  \"sizes\": [\n    \"17.7 GB (282 files)\"\n  ],\n  \"formats\": [\n    \".html\",\n    \".json\",\n    \".md\",\n    \".set\",\n    \".tsv\",\n    \".yaml\",\n    \".yml\"\n  ],\n  \"source_hash\": \"0b4617b6c04bde246bc9acb7298ecf221c4499ff8c9db2972506f136e32512b5\"\n}","last_activity_at":"2026-08-16 13:28:05","source":null,"source_id":null,"subject_count":40,"modalities":"eeg","age_min":22.8,"age_max":22.8,"file_size":17751308998,"total_files":2693,"tasks":"ssvep","metadata_columns_error":null,"staleness_warn_stage":null,"staleness_admin_notified_at":null,"authors":"Heegyu Kim, Kyungho Won, Minkyu Ahn, Sung Chan Jun","license":"CC BY 4.0","readme":"[![DOI](https://img.shields.io/badge/DOI-10.82901%2Fnemar.nm000127-blue)](https://doi.org/10.82901/nemar.nm000127)\n\n# 40-class beta-range SSVEP speller dataset\n\n40-class beta-range SSVEP speller dataset.\n\n## Dataset Overview\n\n- **Code**: Kim2025BetaRange\n- **Paradigm**: ssvep\n- **DOI**: 10.1038/s41597-025-06032-2\n- **Subjects**: 40\n- **Sessions per subject**: 6\n- **Events**: 14=1, 15=2, 16=3, 17=4, 18=5, 19=6, 20=7, 21=8, 14.2=9, 15.2=10, 16.2=11, 17.2=12, 18.2=13, 19.2=14, 20.2=15, 21.2=16, 14.4=17, 15.4=18, 16.4=19, 17.4=20, 18.4=21, 19.4=22, 20.4=23, 21.4=24, 14.6=25, 15.6=26, 16.6=27, 17.6=28, 18.6=29, 19.6=30, 20.6=31, 21.6=32, 14.8=33, 15.8=34, 16.8=35, 17.8=36, 18.8=37, 19.8=38, 20.8=39, 21.8=40\n- **Trial interval**: [0.0, 5.0] s\n- **File format**: MAT\n\n## Acquisition\n\n- **Sampling rate**: 1024.0 Hz\n- **Number of channels**: 31\n- **Channel types**: eeg=31, misc=2\n- **Montage**: standard_1005\n- **Hardware**: BioSemi ActiveTwo\n- **Software**: OpenViBE\n- **Reference**: CMS/DRL\n- **Ground**: CMS/DRL near Pz\n- **Sensor type**: active\n- **Line frequency**: 60.0 Hz\n- **Impedance threshold**: 5 kOhm\n- **Cap manufacturer**: BioSemi\n- **Electrode type**: wet\n- **Electrode material**: Ag/AgCl\n\n## Participants\n\n- **Number of subjects**: 40\n- **Health status**: healthy\n- **Age**: mean=22.8, std=3.34, min=20, max=35\n- **Gender distribution**: male=25, female=15\n- **BCI experience**: 3 of 40 had prior SSVEP-BCI experience\n\n## Experimental Protocol\n\n- **Paradigm**: ssvep\n- **Task type**: speller\n- **Number of classes**: 40\n- **Class labels**: 14, 15, 16, 17, 18, 19, 20, 21, 14.2, 15.2, 16.2, 17.2, 18.2, 19.2, 20.2, 21.2, 14.4, 15.4, 16.4, 17.4, 18.4, 19.4, 20.4, 21.4, 14.6, 15.6, 16.6, 17.6, 18.6, 19.6, 20.6, 21.6, 14.8, 15.8, 16.8, 17.8, 18.8, 19.8, 20.8, 21.8\n- **Trial duration**: 5.0 s\n- **Feedback type**: none\n- **Stimulus type**: JFPM visual flicker\n- **Stimulus modalities**: visual\n- **Primary modality**: visual\n- **Synchronicity**: synchronous\n- **Mode**: offline\n- **Training/test split**: True\n\n## HED Event Annotations\n\nSchema: HED 8.4.0 | Browse: https://www.hedtags.org/hed-schema-browser\n\n```\n  14\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14\n\n  15\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15\n\n  16\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/16\n\n  17\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/17\n\n  18\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/18\n\n  19\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/19\n\n  20\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/20\n\n  21\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/21\n\n  14.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_2\n\n  15.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_2\n\n  16.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/16_2\n\n  17.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/17_2\n\n  18.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/18_2\n\n  19.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/19_2\n\n  20.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/20_2\n\n  21.2\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/21_2\n\n  14.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_4\n\n  15.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_4\n\n  16.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/16_4\n\n  17.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/17_4\n\n  18.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/18_4\n\n  19.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/19_4\n\n  20.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/20_4\n\n  21.4\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/21_4\n\n  14.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_6\n\n  15.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_6\n\n  16.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/16_6\n\n  17.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/17_6\n\n  18.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/18_6\n\n  19.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/19_6\n\n  20.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/20_6\n\n  21.6\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/21_6\n\n  14.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/14_8\n\n  15.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/15_8\n\n  16.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/16_8\n\n  17.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/17_8\n\n  18.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/18_8\n\n  19.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/19_8\n\n  20.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/20_8\n\n  21.8\n    ├─ Sensory-event\n    ├─ Experimental-stimulus\n    ├─ Visual-presentation\n    └─ Label/21_8\n\n```\n## Paradigm-Specific Parameters\n\n- **Detected paradigm**: ssvep\n- **Stimulus frequencies**: [14.0, 14.2, 14.4, 14.6, 14.8, 15.0, 15.2, 15.4, 15.6, 15.8, 16.0, 16.2, 16.4, 16.6, 16.8, 17.0, 17.2, 17.4, 17.6, 17.8, 18.0, 18.2, 18.4, 18.6, 18.8, 19.0, 19.2, 19.4, 19.6, 19.8, 20.0, 20.2, 20.4, 20.6, 20.8, 21.0, 21.2, 21.4, 21.6, 21.8] Hz\n- **Frequency resolution**: 0.2 Hz\n\n## Data Structure\n\n- **Trials**: 240\n- **Blocks per session**: 6\n\n## Preprocessing\n\n- **Data state**: epoched\n\n## Signal Processing\n\n- **Classifiers**: CCA, FBCCA, ITCCA, TRCA, EEGNet\n- **Feature extraction**: CCA, FBCCA, TRCA\n- **Frequency bands**: stimulus_range=[14.0, 22.0] Hz; analysis=[13.0, 89.0] Hz\n- **Spatial filters**: CCA, TRCA\n\n## Cross-Validation\n\n- **Method**: leave-one-subject-out\n- **Folds**: 6\n- **Evaluation type**: within_subject, cross_subject\n\n## BCI Application\n\n- **Applications**: speller\n- **Environment**: lab\n\n## Tags\n\n- **Pathology**: healthy\n- **Modality**: visual\n- **Type**: perception\n\n## Documentation\n\n- **DOI**: 10.1038/s41597-025-06032-2\n- **License**: CC BY 4.0\n- **Investigators**: Heegyu Kim, Kyungho Won, Minkyu Ahn, Sung Chan Jun\n- **Senior author**: Sung Chan Jun\n- **Institution**: Gwangju Institute of Science and Technology\n- **Department**: School of Electrical Engineering and Computer Science, GIST\n- **Country**: KR\n- **Repository**: Figshare\n- **Data URL**: https://doi.org/10.6084/m9.figshare.28806815.v2\n- **Publication year**: 2025\n- **Ethics approval**: GIST IRB, No. 20211201-HR-64-02-04\n- **Keywords**: SSVEP, BCI, beta range, visual fatigue, 40-class speller, JFPM, EEG\n\n## References\n\nH. Kim, K. Won, M. Ahn, and S. C. Jun, \"A 40-class SSVEP speller dataset: beta range stimulation for low-fatigue BCI applications,\" Scientific Data, vol. 12, p. 1751, 2025. 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