Brain stimulation sparks insight
February 8, 2011
Experience can be a disadvantage, since preconceptions may limit our ability to creatively solve a problem we think we've seen before. However, stimulating the brain in a certain way may provide flashes of insight, according to two scientists.In a study of 67 adults, researchers found that electrical stimulation of two parts of the brain prompted three times as many participants to come up with an insightful solution to a puzzle compared with those who didn't receive a brain zap.
""Our experiences can blind us,"" write Richard Chi and Allan Snyder of the Centre for the Mind at the University of Sydney, in Australia, in the Feb. 2 issue of the journal PLoS ONE.
""Once we have learned to solve problems by one method, we often have difficulties in generating solutions involving a different kind of insight.""
Chi and Snyder set out to temporarily induce a mental state less constrained by preconceptions, focusing on the brain's anterior temporal lobes, located just above the ears.
The left anterior temporal lobe is associated with maintaining existing concepts and representations of these concepts; research has shown that when this brain region is inhibited, people are less likely to draw on their preconceived notions.
The right anterior temporal lobe, meanwhile, is associated with insight.
------Matchstick arithmetic puzzles
They gave study participants ""matchstick arithmetic"" puzzles, in which matchsticks spelled out inaccurate equations in Roman numerals.
Participants had to correct the statements by moving only one stick. They first solved 27 puzzles all with a particular type of solution - making an ""X"" into a ""V.""
Afterward, participants received - or were told they had received, for the control group - electrical stimulation.
For some participants, the stimulation activated the right anterior temporal lobes of their brains, while inhibiting the left anterior temporal lobes. They then solved puzzles with different types of solutions, for instance, making a ""+"" into a ""=.""
Of the participants who were told they had received stimulation (but actually did not), 20 percent solved the most difficult of the insight problems in the allotted time.
However, among the participants whose right anterior lobes were excited and left anterior lobes inhibited, 60 percent succeeded in solving the puzzles.
(Another set of subjects received reverse stimulation, which activated the left, but depressed the right. Their performances were similar to those who received no stimulation.)
This is the strongest cognitive enhancement the researchers say they are aware of for a brain-stimulation study - however, it may be due to several mechanisms, including changing the way one thinks (basing solutions on past experiences versus going in with an open mind, for example) and facilitating insight directly.
In their paper, the researchers quote the economist John Maynard Keynes: The ""difficulty lies, not in the new ideas, but in escaping from the old ones, which ramify...into every corner or our mind.""
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