diff --git a/src/derivatives/ephys.md b/src/derivatives/ephys.md index 5248b98c11..ac7ead22ec 100644 --- a/src/derivatives/ephys.md +++ b/src/derivatives/ephys.md @@ -5,16 +5,16 @@ This includes minimally processed data, but excludes data that has undergone ext ## Minimally processed electrophysiological data -A minimally processed EEG, MEG or iEEG data can be stored as a derivative, using the same file formats as specified for raw EEG, MEG, or iEEG. -Examples for this are MaxFiltered MEG data, or re-referenced and bandpass-filtered EEG data. +A minimally processed EEG, MEG or iEEG data can be stored as a derivative using the same file formats as specified for raw EEG, MEG, or iEEG. +Examples of this are MaxFiltered MEG data or re-referenced and bandpass-filtered EEG data. Certain file formats that are allowed in BIDS for raw data have limited representation to some extent, -for example the EDF and BDF formats cannot be used to store epoched (or "segmented") data in a standardized way, -whereas the BrainVision and FIF file formats can. +for example, the EDF and BDF formats cannot be used to store epoched (or "segmented") data in a standardized way, +whereas the EEGLAB .set, the BrainVision Core Data Format 1.0 and the FIF file formats can. These limitations should be taken into account when writing derivative data back to disk. -The representation of the data MUST follow the general derivative conventions and the Common file level metadata fields, +The representation of the data MUST follow the general derivative conventions and the Common file-level metadata fields, notably the use of the [`desc` entity](../appendices/entities.md#desc). -If minimally processed data is the result from processing a BIDS dataset, then it MUST be marked as a derivative and the source data must be specified. +If minimally processed data is the result of processing a BIDS dataset, then it MUST be marked as a derivative dataset in the dataset_description.json file, and the source data must be specified. The processing steps MUST be indicated in the [`desc` entity](../appendices/entities.md#desc), where the label is a description identifier that distinguishes it from the original raw data. @@ -26,12 +26,12 @@ the [`desc` entity](../appendices/entities.md#desc) is not needed to distinguish The description of the processing in the derivative MUST be clarified in the [descriptions.tsv](common-data-types.md#descriptions-tsv) file, with at least two columns for desc_id and the actual description. -Other columns MAY be added but are at this moment not standardized. +Other columns MAY be added but are, at this moment, not standardized. The [descriptions.tsv](common-data-types.md#descriptions-tsv) file SHOULD include sufficient information to document the details of the data processing that resulted in the derivative. The `_eeg.json`, `_meg.json`, or `_ieeg.json` sidecar files MUST be replicated alongside the respective derivative `_eeg.`, `_meg.`, or `_ieeg.` data files, so that they can be processed as if it were a raw BIDS dataset. -The json sidecar file must be compliant with those for raw data and SHOULD NOT include fields that are specific to the processing that was done on the data. +The JSON sidecar file must be compliant with those for raw data and SHOULD NOT include fields that are specific to the processing that was done on the data. ## MaxFiltered MEG data