on005261
NEMAR copy of ds005261

Gloups_MEG

This magnetoencephalography (MEG) dataset comprises recordings from 17 adult participants performing a learning task and resting-state condition using a 4D NeuroImaging system with 248 magnetometer channels. This is a NEMAR-hosted version of OpenNeuro dataset ds005261 (v2.0.0), part of a multimodal neuroimaging study investigating speech sequence production and phonotactic constraints. The MEG recordings provide complementary temporal resolution for understanding cortico-cerebellar mechanisms underlying speech production. Related fMRI data from the same participants are available in OpenNeuro dataset ds004597.

BEH MEG
Issues GitHub OpenNeuro ds005261

Download this dataset

Pick a method. Large datasets skip the zip and use the streaming methods below — all resumable. Full download guide →

  1. NEMAR CLI recommended

    Pulls the pinned version + annexed data and resumes cleanly. Install nemar-cli → 

    nemar dataset download on005261
  2. DataLad

    Clone the dataset repo and fetch file content on demand. Docs → 

    datalad clone https://github.com/nemarDatasets/on005261 on005261
cd on005261 && datalad get .
  3. git-annex

    Plain git + git-annex against the dataset repo. Docs → 

    git clone https://github.com/nemarDatasets/on005261 on005261
cd on005261 && git annex get .
  4. Direct files (wget / curl / rclone)

    Every file with a stable, range-resumable URL from the manifest. Needs curl, jq, wget (or rclone/aria2c). Docs → 

    curl -s https://data.nemar.org/on005261/v1.0.0/manifest.json | jq -r '.[].bytes_url' > urls.txt
wget -xc -i urls.txt

Compute on this dataset

Two routes today, with a third (in-browser one-click submission) landing soon.

  1. NeuroScience Gateway (NSG) portal.

    NSG runs EEGLAB / Brainstorm / MNE pipelines on supercomputing time donated by SDSC. Create an account, point a job at this dataset's S3 prefix (s3://nemar/on005261), and submit.
    nsgportal.org →

  2. Local processing with nemar-cli.

    Pull the dataset to your machine and run any toolbox locally. Honors the published version pinning. 

    npm install -g nemar-cli
nemar dataset clone on005261
cd on005261 && nemar dataset get
  3. Just the files.

    rclone, aria2c, or any HTTPS client works against data.nemar.org/on005261/ — the manifest carries presigned S3 URLs.

Direct compute access is coming soon. One-click NSG submission from this page is scoped for a follow-up phase. Tracked on nemarOrg/website#6.

Citations

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    Files

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    Signal viewer
    How to use the data (for agentic research) license, citation, download commands, Zarr access

    What it is

    Modalities
    BEH, MEG
    Participants
    17
    Size
    225 GB
    Tasks
    MEGloupsA1, MEGloupsA1-seq1, MEGloupsA1-seq2, MEGloupsA1-seq3, MEGloupsA1-seq4, MEGloupsA1-seq5, MEGloupsA1-seq6, MEGloupsA1-seq7, MEGloupsA1-seq8, MEGloupsA1-seq9, MEGloupsA2, MEGloupsA2-seq1, MEGloupsA2-seq2, MEGloupsA2-seq3, MEGloupsA2-seq4, MEGloupsA2-seq5, MEGloupsA2-seq6, MEGloupsA2-seq7, MEGloupsA2-seq8, MEGloupsA2-seq9, MEGloupsB1, MEGloupsB1-seq1, MEGloupsB1-seq2, MEGloupsB1-seq3, MEGloupsB1-seq4, MEGloupsB1-seq5, MEGloupsB1-seq6, MEGloupsB1-seq7, MEGloupsB1-seq8, MEGloupsB1-seq9, MEGloupsB2, MEGloupsB2-seq1, MEGloupsB2-seq2, MEGloupsB2-seq3, MEGloupsB2-seq4, MEGloupsB2-seq5, MEGloupsB2-seq6, MEGloupsB2-seq7, MEGloupsB2-seq8, MEGloupsB2-seq9, MEGloupsC1, MEGloupsC1-seq1, MEGloupsC1-seq2, MEGloupsC1-seq3, MEGloupsC1-seq4, MEGloupsC1-seq5, MEGloupsC1-seq6, MEGloupsC1-seq7, MEGloupsC1-seq8, MEGloupsC1-seq9, MEGloupsC2, MEGloupsC2-seq1, MEGloupsC2-seq2, MEGloupsC2-seq3, MEGloupsC2-seq4, MEGloupsC2-seq5, MEGloupsC2-seq6, MEGloupsC2-seq7, MEGloupsC2-seq8, MEGloupsC2-seq9, MEGloupsD1, MEGloupsD1-seq1, MEGloupsD1-seq2, MEGloupsD1-seq3, MEGloupsD1-seq4, MEGloupsD1-seq5, MEGloupsD1-seq6, MEGloupsD1-seq7, MEGloupsD1-seq8, MEGloupsD1-seq9, MEGloupsD2, MEGloupsD2-seq1, MEGloupsD2-seq2, MEGloupsD2-seq3, MEGloupsD2-seq4, MEGloupsD2-seq5, MEGloupsD2-seq6, MEGloupsD2-seq7, MEGloupsD2-seq8, MEGloupsD2-seq9, MEGloupsRest, TestAudioTraining, gloups, gloups-epo, rest

    License and terms

    License
    CC0
    Recommended citation
    Todorovic, S., Runnqvist, E., Chanoine, V., & Badier, J. (2026). Gloups_MEG (Version v1.0.0) [Data set]. NEMAR. https://doi.org/10.82901/nemar.on005261

    Where the bytes are

    Latest version (always current)
    https://data.nemar.org/on005261/latest/
    This version (v1.0.0)
    https://data.nemar.org/on005261/v1.0.0/

    How to download

    The dataset
    nemar dataset download on005261 Clones 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
    nemar dataset download on005261 --subjects sub-01,02 Also filters by --sessions, --tasks, --runs, --datatypes, --include and --exclude.
    A subset, step 1
    nemar dataset clone on005261 Clones git-annex pointers only; fetches no file content. Creates ./on005261.
    A subset, step 2
    cd on005261 The 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/on005261/v1.0.0/participants.tsv A direct HTTPS fetch works for any single file.

    Assess fit without downloading

    Participants table
    https://data.nemar.org/on005261/v1.0.0/participants.tsv
    Dataset description
    https://data.nemar.org/on005261/v1.0.0/dataset_description.json
    Directory listing
    https://data.nemar.org/on005261/v1.0.0/?format=json
    Catalog record
    https://api.nemar.org/datasets/on005261

    Working with the Zarr copy

    1. Start at the index
    https://zarr.nemar.org/on005261/zarr/index.json The mandatory entry point. Never hardcode a bucket path.
    2. Pick a store entry
    stores[].zarr, stores[].groups[].name These 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
    s3://nemar/on005261/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
    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
    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
    physical = digital * scale + offset scale 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
    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
    index.json Only 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
    root.attrs["nemar"] The store carries its own dataset id, DOI, license, citation and source commit.
    10. Filter for pipelines
    has_zarr=1 This 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).