Brain Activity During Constraint Relaxation in the Insight Problem-Solving Process: An fNIRS Study

People solve insight problems that they encounter daily with a sudden sense of aha! to reach a solution. Chunk decomposition, which decomposes the factors of the problem, and constraint relaxation, which manipulates filters to organize the information necessary to solve the problem, are important in insight problem-solving. Although there have been many studies on brain activity during chunk decomposition, few have examined brain activity during constraint relaxation. Particularly, no study has observed the changes over time due to constraint relaxation during insight problem-solving. This study used a slot machine task as an insight problem to measure brain activity using functional Near-Infrared Spectroscopy (fNIRS), and eye movements to estimate constraint relaxation. The results showed that the right dorsolateral prefrontal cortex (DLPFC) and right superior temporal gyrus (STG) were activated over time in participants in whom constraint relaxation was induced. The right inferior temporal gyrus (ITG) of participants who were able to solve the insight problem after constraint relaxation was also activated. The analysis of brain activity during constraint relaxation in insight problem-solving may be useful for advancing research on the aha! phenomenon and creativity.