Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[ENH] Define "modality" and clarify "data type" #592

Merged
merged 2 commits into from
Sep 16, 2020
Merged

[ENH] Define "modality" and clarify "data type" #592

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c7b3932
ENH: Define "modality"
effigies Sep 1, 2020
f567a09
ENH: Note that data types are the directories containing data files
effigies Sep 10, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 23 additions & 6 deletions src/02-common-principles.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,12 +33,19 @@ misunderstanding we clarify them here.
a brain scanning instrument was acquiring data according to particular
scanning sequence/protocol.

1. **Data type** - a functional group of different types of data. In BIDS we
define eight data types: `func` (task based and resting state functional MRI),
`dwi` (diffusion weighted imaging), `fmap` (field inhomogeneity mapping data
such as field maps), `anat` (structural imaging such as T1, T2, etc.), `meg`
(magnetoencephalography), `eeg` (electroencephalography), `ieeg` (intracranial
electroencephalography), `beh` (behavioral).
1. **Data type** - a functional group of different types of data.
BIDS defines eight data types:
`func` (task based and resting state functional MRI),
`dwi` (diffusion weighted imaging),
`fmap` (field inhomogeneity mapping data such as field maps),
`anat` (structural imaging such as T1, T2, etc.),
`meg` (magnetoencephalography),
`eeg` (electroencephalography),
`ieeg` (intracranial electroencephalography),
`beh` (behavioral).
Data files are contained in a directory named for the data type.
In raw datasets, the data type directory is nested inside subject and
(optionally) session directories.

1. **Task** - a set of structured activities performed by the participant.
Tasks are usually accompanied by stimuli and responses, and can greatly vary
Expand All @@ -57,6 +64,16 @@ misunderstanding we clarify them here.
due to different subject response or randomized nature of the stimuli). Run
is a synonym of a data acquisition.

1. **Modality** - the category of brain data recorded by a file.
For MRI data, different pulse sequences are considered distinct modalities,
such as `T1w`, `bold` or `dwi`.
For passive recording techniques, such as EEG, MEG or iEEG,
the technique is sufficiently uniform to define the modalities `eeg`,
`meg` and `ieeg`.
effigies marked this conversation as resolved.
Show resolved Hide resolved
When applicable, the modality is indicated in the **suffix**.
The modality may overlap with, but should not be confused with
the **data type**.

1. **`<index>`** - a nonnegative integer, possibly prefixed with arbitrary number of
0s for consistent indentation, e.g., it is `01` in `run-01` following
`run-<index>` specification.
Expand Down