April 13, 2004 -- It may not appear in the shape of a light bulb above your head, but researchers say "Aha!" moments are marked by a surge of electrical activity in the brain.
A new study shows that solving a problem that requires creative insight prompts distinct changes in brain activity that don't occur under normal problem-solving conditions.
"For thousands of years people have said that insight feels different from more straightforward problem solving," says researcher Mark Jung-Beeman, an associate professor of psychology at Northwestern University, in Evanston, Ill. in a news release. "We believe this is the first research showing that distinct computational and neural mechanisms lead to these breakthrough moments."
Surge of Brain Activity Accompanies 'Aha!' Moments
In the study, which appears in the April issue of PloS Biology, researchers compared brain activity in two different experiments.
In the first, study participants were given a series of word problems to solve designed to evoke a distinct "Aha!" moment about half the time they were solved. Using brain imaging techniques, researchers found that activity increased in a small part of the right lobe of the brain called the temporal lobe when the participants reported experiencing creative insight during problem solving. Little activity was detected in this area during noninsight solutions.
Researchers say previous studies have shown that this right temporal lobe may be important for drawing distantly related information together, which is a key component of insight.
In the second experiment, researchers monitored the participants' brainwave activity using an electroencephalogram (EEG) during insight and noninsight problem solving tasks.
The study showed that about one-third of a second before the "Aha!" moment, there was a sudden burst of high-frequency brain waves. This type of activity is associated with high-level processing of information, and researchers say it was also centered in the same right temporal lobe area.
In addition, a second smaller wave of electrical activity was seen on EEG. About 1.5 seconds before the moment of insight, there was an increase in lower frequency brain waves in this area of the brain, which disappeared when the high-frequency activity began.
Researchers say this "gating" effect might occur to allow weak solution-related activity to gain momentum and then burst into consciousness as insight.
"This is like closing your eyes so you can concentrate when you are trying to solve a difficult problem," says researcher John Kounios of Drexel University in a news release. "But in this case, your brain is blocking out just the visual inputs to your right hemisphere."
Researchers say that these clues may help scientists better understand the creative insight process and its impact on the brain.