Knowledge Base

Problem

A researcher wants to synchronize a participant's facial video (captured by a face-tracking camera) with what is being displayed on a screen (e.g., websites, stimuli images), mark different stimulus presentation intervals, and compare responses across participants.

Details

FaceReader does not directly capture screen content or synchronize external display feeds on its own. The recommended workflow involves recording both the face camera and the stimulus display in MediaRecorder first, then using FaceReader's event and stimulus marking tools on the combined recording. This is relevant for eye-tracking-adjacent studies, UX research, and stimulus-response paradigms.

Solution

1. Set up MediaRecorder to capture both the face camera feed and the screen/stimulus content simultaneously before running participants.
2. Record the session in MediaRecorder so that the facial video and stimulus display are captured in sync within a single recording session.
3. Import the resulting video(s) into FaceReader for analysis.
4. Within FaceReader, use the event marking feature to annotate when specific stimuli were shown (e.g., marking the onset and offset of each stimulus presentation).
5. Add stimulus videos or images to the FaceReader project timeline as appropriate to align analysis segments with stimulus periods.
6. Repeat the same analysis structure across participants to enable cross-participant comparison of facial responses to each stimulus.