Alternate between classifying stimuli by color, shape, or number. The rule changes unpredictably, testing your cognitive flexibility.
1. A shape with a color and number appears on screen.
2. A rule banner tells you what to classify: Color, Shape, or Number.
3. Select the correct answer from 4 options. The rule switches unpredictably.
Switch trials (when the rule changes) are harder and earn bonus points. Your "switch cost" (slower response on switches) reveals cognitive flexibility.