Dr. John Kounios and His Research Team Explain the “Eureka!” Effect in Solving Problems

After a two-year study, Professor of Psychology Dr. John Kounios and his research team have discovered the way the brain operates when sudden insights occur.

In two studies, participants were presented with a series of word problems to solve. Each problem presented three words and asked participants to think of one word that would form a compound word or phrase with each of the words.

In addition to solving the problem, each person reported whether or not the solution occurred as a sudden insight. The problems were designed to be solved with the sudden, “Aha! Eureka!” effect. Brain activity was assessed while participants tackled and solved these problems.

In the first experiment, functional magnetic resonance imaging (fMRI) revealed increased activity in a small part of the right temporal lobe (the anterior superior temporal gyrus) during insight solutions and little activity during non-insight solutions. No insight effect was observed anywhere within the temporal lobe of the left hemisphere. Prior evidence suggests that the right temporal area, which is associated with insight, may be important for drawing distantly related information together when comprehending complex language.

In the second experiment, an electroencephalogram (EEG) tracked brainwave activity during insight and non-insight solutions. About one-third of a second before the subjects indicated solutions achieved through insight, there was a sudden burst of high- frequency (gamma band) activity, relative to solutions achieved without insight. This neural activity, often associated with complex cognitive processing, was observed by scalp electrodes over the same right temporal area observed with fMRI, replicating the effect with new participants and a different measure of brain activity.

“We believe that this burst of electrical activity in the brain reflects the sudden awareness of the problem solution. This corresponds to insight and likely reflects a neural correlate of consciousness,” said Kounios.

A second, unexpected EEG effect also was observed: About 1.5 seconds prior to insight solutions, an increase in lower frequency (alpha band) activity appeared over the right posterior cortex. This effect disappeared precisely when the high-frequency activity began over the right temporal lobe. The researchers interpreted the posterior effect as evidence of “gating,” or attenuation, of visual input, and suggested that this occurs to allow initially weak solution-related activity to gain strength, then burst into consciousness as an insight.

“This is like closing your eyes so you can concentrate when you are trying to solve a difficult problem,” said Kounios. “But in this case, your brain is blocking out just the visual inputs to your right hemisphere.”

In a follow-up study Kounios presented findings showing that the state of the brain immediately prior to the presentation of a problem predicts whether it will be solved by a sudden insight, or by a more gradual, mundane process. The findings suggest that it may some day be possible to develop techniques that facilitate this state of preparation, thereby enhancing creative, insightful, problem solving.

Northwestern University professor Mark Jung-Beeman, and Northwestern researcher Edward Bowden were a part of the research team. Their findings appeared in media outlets throughout the country, including Scientific American, ABC News, National Public Radio, BBC World Service, The Times (London), Discovery Channel Canada and U.S.News &World Report.