Classify numbers according to the current rule. The rule can change at any time — watch the badge!
How to Play
A number and a colored badge indicating the current rule appear on screen
Quickly determine the rule based on the badge color
Press the left or right button to classify the number according to the rule
Core Rule: Classify by Rule
If the badge is Odd/Even (blue), classify by parity. If High/Low (orange), classify relative to 5. Applying the wrong rule is incorrect!
Core Rule: Switch Cost
The hardest moment is when the rule suddenly changes. Still applying the old rule after a switch is incorrect.
Rules
A number (1-9, excluding 5) and a rule badge appear on screen.
Odd/Even rule (blue badge): press left for odd, right for even.
High/Low rule (orange badge): press left if less than 5, right if greater.
Prime rule (violet badge, hard): press left for primes (2, 3, 7), right otherwise.
The rule can switch between trials — quickly check the badge color.
Tip
Check the badge color first, then classify the number
Right after a rule switch is the hardest — pause briefly and verify
Practicing the color-rule association reduces switch cost over time
The Task Switching paradigm is a core measure of cognitive flexibility. Switch cost — the slowdown when rules change — is an early indicator of cognitive aging.
Monsell, S. (2003) - Task switching, Trends in Cognitive Sciences
Kray & Lindenberger (2000) - Adult age differences in task switching