Stroop effect.

The Stroop effect is a cognitive psychology phenomenon that describes the difficulty of naming the ink color of a printed word while ignoring the word itself. When the word is a color-word printed in an incongruent color (for example, the word green printed in purple ink), it frequently takes more time to name the ink color. The degree of time varies from person to person, but this interference in visual processing is a measure of cognitive function and flexibility and attentional control. The Stroop effect is studied in research on attention, memory, and processing speed. It is also used in clinical and educational evaluations aiding the diagnoses of attention deficit hyperactivity disorder (ADHD), early onset Alzheimer’s disease, dyslexia, reading disabilities, and traumatic brain injury.