log_event
Record experimenter-defined events like task onsets, subject reports, or notes against a session's timeline, with optional marker-channel insertion and structured payloads for later analysis.
Instructions
Record an event against the stream's clock.
For anything the server did not generate itself: a task onset, a subject report, an experimenter note. Stimulation commands are logged automatically by send_stim_event, so do not log those by hand.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| label | Yes | Event name, e.g. 'trial_start' or 'eyes_closed'. | |
| value | No | Numeric code. Also written to the board's marker channel when mark_in_stream is set; BrainFlow reserves 0, so use a nonzero value. | |
| payload | No | Any extra structured detail to keep with the event. | |
| duration | No | Event duration in seconds. 0 for an instantaneous event. | |
| session_id | Yes | The session to annotate. | |
| mark_in_stream | No | Also punch the value into the acquisition stream's own marker channel, so the recording carries the event independently. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||