Final answer:
The Stroop effect occurs when controlled processes overrule automatic processes.
Step-by-step explanation:
The correct description of the Stroop effect is option 4: The Stroop effect occurs when controlled processes overrule automatic processes. The Stroop effect is a phenomenon in psychology where the brain experiences interference in processing conflicting information.
This is commonly observed in the Stroop task, where participants are asked to name the ink color of words that spell out different color names, resulting in slower response times when the ink color and word color are incongruent.