The difficulty level of the task is one of the key moderating variables that influence the neural efficiency hypothesis. In a study, it was found that the hypothesis only holds for easy tasks. For difficult tasks, intelligent individuals may show increased brain activation. The study revealed that participants with high IQ showed weaker activation during easy tasks but had a significant increase from easy to difficult tasks. This pattern was not observed in the average IQ group. The study suggests that the relationship between intelligence and brain activation depends on the difficulty of the task.
