Ephys: Terminology

Due to the divergent development process, some different terminology has evolved between the imaging and ephys pipelines. This page, and it’s imaging twin, will cover some of the distinctions.

Sessions, Tasks, and Recordings

In the Ephys pipeline, the top level grouping of recording data is the Session, approximately equivalent to the Imaging pipeline’s MetaSession.

A Session collectively groups together some quantity of electrophysiology and/or tracking data, gathered at the same time and within the same recording room.

A Session may contain one or more Recordings. A Recording is a single, contiguous, block of acquired data, within a single session. Multiple recordings are supported in the case of either breaking up individual epochs, or in the case of some technical malfunction causing data acquisition to end unintentionally, and then be re-started.

A Session may contain one or more Tasks. A Task is a contiguous block of time in which a single activity is monitored. For example, a Task might consist of the subject running in an open field. A Task is associated with a single arena, objects in the arena, etc.

Tasks may or may not correspond to separate Recordings. The two concepts are not necessarily linked, although researchers may find it convenient to stop and start data acquisition (starting a new Recording) as a way to indicate the end of one Task and the beginning of another.

One Recording may contain multiple Tasks, and one Task may be split across multiple Recordings.

Both Recordings and Tasks are approximately equivalent to the concept of session in the Imaging Pipeline.

Task Events

Task Events provide a way to label things that occur within a broader Task. For example, the timing of stimulation events, such as photo-stimulation or provision of rewards.

The TaskEvent table can more properly be understood as a task event stream: a single entry in the TaskEvent table provides space to store an array of start and stop times - e.g. all of the on and off times of laser pulses for photo-stimulation.