Video tutorials
Narrated walkthroughs of Open Lab and of building tasks in the lab.js builder. Each has subtitles in 12 languages, chapters and a transcript, the files to follow along directly under the player, and a link to its docs page.
Files for this video
- ↓ instructions.jsonThe builder file this video starts from (the end of the previous video).
- ↓ practice.jsonThe builder file at the end of this video. The next video starts from it.
The lab.js builder: a reaction-time task, step by step
A practice block with feedback
4:27 · narrated, with subtitles in 12 languages · recorded in November 2026
A short practice before the main task of the reaction-time task: a frame that keeps the two keys on screen, the same trial shown in both loops with Clone, a column that tells the screens which block is running, and a message after each practice trial.
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