nm000266 NEMAR-native dataset
Sosulski et al. 2019 — Online Optimization of Stimulation Speed in an Auditory Brain-Computer Interface under Time Constraints
An auditory event-related potential dataset from 13 healthy subjects performing an oddball paradigm with two sinusoidal tones (target 1000 Hz, non-target 500 Hz) presented at variable stimulus onset asynchronies (60-600 ms). The dataset comprises 31-channel EEG recordings at 1000 Hz acquired with BrainProducts BrainAmp DC during an online closed-loop brain-computer interface experiment designed to optimize stimulation parameters using Bayesian optimization and random search strategies.
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Coming soon. Per-file data-quality summaries are precomputed by the NEMAR processing pipeline. The static aggregate is on the way — tracked at nemar-cli#511.
Files
How to use the data (for agentic research) license, citation, download commands, Zarr access
What it is
- Modalities
- EEG
- Participants
- 13
- Size
- 3.68 GB
- Tasks
- p300
- HED version
- 8.4.0
License and terms
- License
- CC-BY-SA-4.0
- Note
- Derivatives must be shared under the same license (CC-BY-SA-4.0).
- Recommended citation
- Sosulski, J., Hübner, D., Klein, A., & Tangermann, M. (2026). Sosulski et al. 2019 — Online Optimization of Stimulation Speed in an Auditory Brain-Computer Interface under Time Constraints (Version v1.0.4) [Data set]. NEMAR. https://doi.org/10.82901/nemar.nm000266
Where the bytes are
- Latest version (always current)
- https://data.nemar.org/nm000266/latest/
- This version (v1.0.4)
- https://data.nemar.org/nm000266/v1.0.4/
How to download
- The dataset
-
nemar dataset download nm000266Clones and fetches in one step. Content under stimuli/ and derivatives/ is skipped by default because those trees can be large; add --stimuli --derivatives for the whole thing. - A subset, one step
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nemar dataset download nm000266 --subjects sub-01,02Also filters by --sessions, --tasks, --runs, --datatypes, --include and --exclude. - A subset, step 1
-
nemar dataset clone nm000266Clones git-annex pointers only; fetches no file content. Creates ./nm000266. - A subset, step 2
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cd nm000266The get command below reads the clone's annex, so it only works from inside the clone. - A subset, step 3
-
nemar dataset get <files>Pulls the files you actually need. Skips stimuli/ and derivatives/ unless the path you ask for is under one of them. - One small file
- https://data.nemar.org/nm000266/v1.0.4/participants.tsv A direct HTTPS fetch works for any single file.
Assess fit without downloading
- Participants table
- https://data.nemar.org/nm000266/v1.0.4/participants.tsv
- Dataset description
- https://data.nemar.org/nm000266/v1.0.4/dataset_description.json
- Directory listing
- https://data.nemar.org/nm000266/v1.0.4/?format=json
- Catalog record
- https://api.nemar.org/datasets/nm000266
Working with the Zarr copy
- 1. Start at the index
- https://zarr.nemar.org/nm000266/zarr/index.json The mandatory entry point. Never hardcode a bucket path.
- 2. Pick a store entry
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stores[].zarr, stores[].groups[].nameThese two fields exist in every index format version, so a recipe that keys on them works against the whole catalog while the back conversion is still in flight. - 3. Build the store URI
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s3://nemar/nm000266/zarr/{store.zarr}Derivable from the store entry alone. An index at format_version 3 or later also publishes contract_base, data_base and s3_uri; use them when they are there, never require them. - 4. Open the store anonymously
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zarr.open_group(store=..., mode="r", zarr_format=3)Anonymous FsspecStore.from_url in region us-east-2, no credentials. zarr_format=3 is required: without it zarr-python probes for Zarr v2 sidecars, and because anonymous ListBucket is denied, S3 answers a missing key with 403 rather than 404 and the open raises. - 5. Read the level-0 array
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root[store.groups[0].name]["0"]Level 0 is the full-rate signal. Never read a view/ array for inference; those exist for display. - 6. Dequantize the samples
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physical = digital * scale + offsetscale and offset are attributes of the level-0 array, one entry per channel; the unit is on the group's channels attribute. - 7. Slice, don't download
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signal[0:4, 0:500]Stream a window of channels and samples; download only when you will touch most of the array. - 8. Know the HTTP contract
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index.jsonOnly index.json is always proxied and edge-cached. A plain GET for a store object, manifest.json or events.parquet 302s to the public S3 object for non-browser clients, so follow redirects, and HEAD is never redirected. - 9. Read the attribution before reuse
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root.attrs["nemar"]The store carries its own dataset id, DOI, license, citation and source commit. - 10. Filter for pipelines
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has_zarr=1This is the converted filter. has_zarr_verified is the stricter one, and its result set can be empty until the daily fidelity sweep reaches a dataset; verification is reported, never a precondition for serving (nemar-cli ADR 0005).