- Fullscreen starts with a 3-2-1. Memorize the letter set (2–6 letters).
- After a brief delay, a probe letter appears somewhere on the screen.
- Right half = YES (in set). Left half = NO (not in set).
- Respond before the time limit. There are 25 trials per run.
Fast saccades during encoding; short fixations; parafoveal registration; re-fixation to varied probe locations.
DLPFC (working memory), parietal network (load/spacing), basal ganglia & SMA (selection), ACC (conflict/error), LC–NE (arousal).
Rapid accept/reject of symbol sets → play calls, jersey recognition, and quick decisions under time pressure.
