FLASH ORDER · 24 TRIALS
Watch two identical light blocks flash milliseconds apart and choose which appeared first.
Play 24 trials with exactly 12 LEFT FIRST and 12 RIGHT FIRST answers. The interval shrinks; mistakes continue.
READY?
Both blocks are identical. Only their onset order changes.
TWO FLASHES WILL PLAY HERE
Keyboard: A or ← chooses LEFT FIRST · L or → chooses RIGHT FIRST · Touch or mouse: use the two large buttons.
HOW TO PLAY
Watch the LEFT and RIGHT light blocks. They have identical visual styling and flash duration.
The two blocks flash once each with a short onset interval between them.
After both flashes finish, choose LEFT FIRST or RIGHT FIRST before the timing bar empties.
VISUAL EVENT ORDER
Both sides use the same block size, color, brightness, flash duration, label spacing, and background. Only onset order differs.
Standard mode gradually reduces the onset interval while balancing which side appears first.
ENTERTAINMENT CHALLENGE
This game is for entertainment and personal practice. It is not a clinical visual, neurological, or temporal-processing test.
Display refresh rate, device performance, brightness, and practice can affect very short flash judgments.
QUESTIONS
Choose the side whose block began flashing first. The buttons unlock only after both flashes finish.
Yes. Size, color, brightness, duration, labels, and surrounding layout are matched between LEFT and RIGHT.
The onset interval gradually shrinks. Endless mode also shortens the answer window after correct judgments.
No. This is a recreational browser game and does not diagnose a medical or neurological condition.