That wonderful moment when the solution to a problem suddenly pops into your head might actually be signaled beforehand by your eyes, a new study finds.
By tracking the eye movements of people in the study, the researchers were able to pinpoint the moment leading up to a person's epiphany, or an "aha" moment.
The researchers were studying what's called "epiphany learning" — in other words, that exact "aha" moment when a person has an "unexpected moment of insight," according to the study, which was published today (April 17) in the journal Proceedings of the National Academy of Sciences.
But because epiphanies are, by nature, "sudden, unexpected and irreversible," it's difficult for scientists to predict when a person will have one, the researchers, James Chen, a graduate student in economics at The Ohio State University; and Ian Krajbich, a professor of psychology at the same institution, wrote in the study.
To zero in on the moment people experienced epiphanies, the researchers asked the 59 students in the study to play a strategy game on a computer.
Here's how the game worked: In each round, two students faced off against each other. Each player was shown the numbers zero to 10 and was asked to pick a number. Without the students’ knowing exactly how the game worked, the computer averaged the numbers that the two players chose and then multiplied that number by 0.9, which resulted in a final number. This final number was displayed to the students, and the player who had initially selected the number closest to this final number was the winner.
"Because the average of the two numbers is by definition halfway between those numbers," and multiplying that average by 0.9 will result in a smaller number, the person who picks the smaller number will always win, the researchers wrote. "Therefore, picking zero is the optimal strategy , regardless of what the other player chooses," they wrote.
Of course, the students playing the game weren't told what the optimal strategy was beforehand. The researchers wanted to see what would happen during the "epiphany" moment when they finally figured it out on their own.
"There's a sudden change in their behavior," Krajbich said in a statement. "They are choosing other numbers, and then all of a sudden, they switch to choosing only zero. That's the hallmark of an epiphany."
In the study, 42 percent of the students figured out the optimal strategy of choosing zero at some point during the game, the researchers found. Another 37 percent committed to a strategy in which they selected the same number over and over, although it was the wrong number, and 20 percent never seemed to develop a strategy.
To see if there were any clues leading up the students' epiphanies, the researchers tracked the students' eye movements as they played the game. In the game, the 10 numbers were displayed in a circle (like that of a rotary phone). After the player selected his or her number, a new screen appeared, asking if the player wanted to commit to his or her choice for the rest of the game — in other words, stick with the number for all of the remaining rounds. The third and final screen that appeared showed the results of the each round.
The researchers found that in the rounds of the game leading up a person's epiphany moment (the moment he or she committed to zero for the remaining games), he or she looked at zero and other low numbers more often than people who didn't have an epiphany, even if the player didn't always choose zero.
"We don't see the epiphany in their choice of numbers, but we see it in their eyes," Chen said in a statement. "Their attention is drawn to zero," he said.
The researchers also looked at pupil dilation , which is a sign that a person is paying close attention and learning, Krajbich said. They found that during each round before the epiphany, the player's pupils dilated when he or she viewed the final screen showing the results. After a player had the epiphany, that person's pupils didn't dilate when the participant viewed the results screen.
The findings suggested that these players were learning before they had their epiphany, while the players who didn’t have epiphanies weren't learning, Krajbich said.
Originally published on Live Science .