A vehicle flashes at the center while a road sign appears near the edge – both gone in a blink. Name the vehicle, then tap where the sign was. Get both right and the flash gets shorter.
MEDIUM
TRIAL1/32
FLASH500ms
BEST—
+
✓
ROUND COMPLETE
Threshold is the flash length your accuracy settled at. Watch it fall across sessions. An asterisk means the staircase did not reverse enough times for a firm reading.