diff --git a/src/modality-specific-files/task-events.md b/src/modality-specific-files/task-events.md index d3507493fd..0a999b0ee3 100644 --- a/src/modality-specific-files/task-events.md +++ b/src/modality-specific-files/task-events.md @@ -454,15 +454,15 @@ In the accompanying JSON sidecar, the `stim_file` column might be described as f ### Referencing Stimulus Identifiers in `events.tsv` -To reference stimulus identifiers in the `events.tsv` file, use the `stim_id` column. The values in the `stim_id` column should represent unique identifiers for the stimuli. +To reference stimulus identifiers in the `events.tsv` file, use the `stim_id` column. The `stim_id` corresponds to the unique identifier of the stimulus files and their annotations stored under the `/stimuli` directory. This allows linking each event to multiple related files associated with that stimulus. Example `events.tsv` file: ```Text -onset duration trial_type response_time stim_file stim_id -1.23 0.65 start 1.435 images/cat01.jpg stim001 -5.65 0.65 stop 1.739 images/cat02.jpg stim002 -12.1 2.35 n/a n/a videos/movie01.mp4 stim003 +onset duration trial_type response_time stim_id +1.23 0.65 start 1.435 stim-face01 +5.65 0.65 stop 1.739 stim-face02 +12.1 2.35 n/a n/a stim-video01 ``` In the accompanying JSON sidecar, the `stim_id` column might be described as follows: @@ -471,11 +471,28 @@ In the accompanying JSON sidecar, the `stim_id` column might be described as fol { "stim_id": { "LongName": "Stimulus identifier", - "Description": "Represents a unique identifier for the stimulus presented at the given onset time." + "Description": "Represents a unique identifier for the stimulus presented at the given onset time. Links to files and annotations in the /stimuli directory." } } ``` +The `stim_id` in the events file links to corresponding files: + +```Text +stimuli/ +├── stim-face01_image.jpg +├── stim-face01_image.json +├── stim-face01_annotations.tsv +├── stim-face02_image.jpg +├── stim-face02_image.json +├── stim-face02_annotations.tsv +├── stim-face02_annotations.tsv +├── stimuli.tsv +└── stimuli.json +``` + +By using `stim_id`, multiple annotations and stimulus files associated with the same identifier can be efficiently linked to events in the `events.tsv` file. The `stim_id` is a unique identifier for the stimulus that can be used to reference the stimulus files, annotations, and metadata stored in `stimuli.tsv` and `stimuli.json`. For more information on the structure of stimulus files and annotations, refer to the [Stimuli](./stimuli.md) BIDS specifications. + ### Advantages of Standardization Standardizing stimulus files and their annotations within the BIDS specifications offers several advantages: