Stay focused. After a random quiet period (2–10 seconds), a millisecond counter will start inside the red box. Press Space or click the box as soon as you see it counting. Your reaction time appears for one second, then the next round begins. 40 valid responses total. Pressing too early counts as a false start.
← BackISI varies randomly each trial (2–10 s).
Lapses are responses slower than 500 ms. False starts are key presses or clicks before the counter starts.