aNNaLs Of sciENcE THE EUREKa HUNT Why do good ideas come to us when they do? BY JONaH LEHRER he summer of 1949 was long and dry So Dodge stopped running. The deci- in Montana. On the afternoon of sion wasn’t as suicidal as it appeared: in a AugustT 5th—the hottest day ever re- moment of desperate insight, he had de- corded in the state—a lightning fire was vised an escape plan. He lit a match and spotted in a remote area of pine forest. A ignited the ground in front of him, the parachute brigade of fifteen firefighters flames quickly moving up the grassy slope. known as smoke jumpers was dispatched Then Dodge stepped into the shadow of to put out the blaze; the man in charge his fire, so that he was surrounded by a was named Wag Dodge. When the buffer of burned land. He wet his hand- jumpers left Missoula, in a C-47 cargo kerchief with water from his canteen, plane, they were told that the fire was clutched the cloth to his mouth, and small, just a few burning acres in the lay down on the smoldering embers. Mann Gulch. He closed his eyes and tried to inhale Mann Gulch, nearly three miles long, the thin layer of oxygen clinging to the is a site of geological transition, where ground. Then he waited for the fire to the Great Plains meet the Rocky Moun- pass over him. tains, pine trees give way to tall grasses, Thirteen smoke jumpers died in the and steep cliffs loom over the steppes of Mann Gulch fire. White crosses below the Midwest. The fire began in the trees the ridge still mark the spots where the on one side of the gulch. By the time the men died. But after several terrifying min- firefighters arrived, the blaze was already utes Dodge emerged from the ashes, vir- out of control. Dodge moved his men tually unscathed. along the other side of the gulch and told them to head downhill, toward the here is something inherently myste- water. rious about moments of insight. When the smoke jumpers started WagT Dodge, for instance, could never ex- down the gulch, a breeze was blowing the plain where his idea for the escape fire flames away from them. Suddenly, the came from. (“It just seemed the logical wind reversed, and Dodge watched the thing to do” was all he could muster.) His fire leap across the gulch and spark the improbable survival has become one of grass on his side. He and his men were those legendary stories of insight, like Ar- only a quarter mile uphill. An updraft chimedes shouting “Eureka!” when he began, and fierce winds howled through saw his bathwater rise, or Isaac Newton the canyon as the fire sucked in the sur- watching an apple fall from a tree and rounding air. Dodge was suddenly staring then formulating his theory of gravity. at a wall of flame fifty feet tall and three Such tales all share a few essential features, hundred feet deep. In a matter of seconds, which psychologists and neuroscientists the fire began to devour the grass, hurtling use to define “the insight experience.” The toward the smoke jumpers at seven hun- first of these is the impasse: before there dred feet a minute. can be a breakthrough, there has to be a Dodge screamed at his men to retreat. mental block. Wag Dodge spent min- They dropped their gear and started run- utes running from the fire, although he ning up the steep canyon walls, trying to was convinced that doing so was futile. reach the top of the ridge. After a few Then, when the insight arrived, Dodge minutes, Dodge glanced over his shoulder immediately realized that the problem and saw that the fire was less than fifty was solved. This is another key feature of yards away. He realized that the blaze insight: the feeling of certainty that ac- couldn’t be outrun; the gulch was too companies the idea. Dodge didn’t have steep, the flames too fast. time to think about whether his plan 40 THE NEW YORKER, JULY 28, 2008 TNY—2008_07_28—PAGE 40—133SC. would work. He simply knew that it sphere is what helps you see the forest.” that insight could be a really interesting would. It wasn’t clear how to pinpoint these way to look at all these skills the right Mark Jung-Beeman, a cognitive neu- nuanced aspects of cognition, because hemisphere excelled at,” he said. “I guess roscientist at Northwestern University, the results of right-hemisphere damage I had an insight about insight.” has spent the past fifteen years trying to were harder to spot than those of left- Jung-Beeman began searching in the figure out what happens inside the brain hemisphere damage. But in 1993 Jung- right hemisphere for the source of insight when people have an insight. “It’s one Beeman heard a talk by the psychologist in the brain. He decided to compare puz- of those defining features of the human Jonathan Schooler on moments of in- zles solved in moments of insight with mind, and yet we have no idea how or sight. Schooler had demonstrated that it those solved by methodical testing of po- why it happens,” he told me. Insights have was possible to interfere with insight by tential solutions, in which people could often been attributed to divine interven- tion, but, by mapping the epiphany as a journey between cortical circuits, Jung- Beeman wants to purge the insight expe- rience of its mystery. Jung-Beeman has a tense smile, a receding hairline, and the wiry build of a long-distance runner. He qualified for the 1988 and 1992 Olympic trials in the fifteen hundred metres, al- though he gave up competitive running after, as he puts it, “everything below the hips started to fall apart.” He now subsists on long walks and manic foot tapping. When Jung-Beeman gets excited about an idea—be it the cellular properties of pyramidal neurons or his new treadmill— his speech accelerates, and he starts to draw pictures on whatever paper is nearby. It’s as if his mind were sprinting ahead of his mouth. Jung-Beeman became interested in the nature of insight in the early nineteen- nineties, while researching the right hemi- sphere of the brain. At the time, he was studying patients who had peculiar pat- terns of brain damage. “We had a number of patients with impaired right hemi- spheres,” he said. “And the doctors would always say, ‘Wow, you’re lucky—it got the right hemisphere. That’s the minor hemi- sphere. It doesn’t do much, and it doesn’t do anything with language.’ ” But it grad- ually became clear to Jung-Beeman that these patients did have serious cognitive problems after all, particularly with un- derstanding linguistic nuance, and he began to suspect that the talents of the right hemisphere had been overlooked. If the left hemisphere excelled at denota- making people explain their thought pro- accurately trace their thought process and tion—storing the primary meaning of a cess while trying to solve a puzzle—a phe- had no sense of surprise when the answer word—Jung-Beeman suspected that the nomenon he called “verbal overshadow- came. Unfortunately, all the classic puz- right hemisphere dealt with connotation, ing.” This made sense to Jung-Beeman, zles developed by scientists to study in- everything that gets left out of a diction- since the act of verbal explanation would sight required insight; if subjects didn’t ary definition, such as the emotional naturally shift activity to the left hemi- solve them in a sudden “Aha!” moment, charge in a sentence or a metaphor. “Lan- sphere, causing people to ignore the more they didn’t solve them at all. In a popular guage is so complex that the brain has to subtle associations coming from the right puzzle known as “the candle problem,” for process it in two different ways at the side of the brain. “That’s when I realized instance, subjects are given a cardboard same time,” he said. “It needs to see the BRUCE ERIC KAPLAN forest and the trees. The right hemi- Brain-imaging techniques are revealing how our minds produce insight. TNY—2008_07_28—PAGE 41—133SC.—LIVE art R17357 box containing a few thumbtacks, a book that can be combined with all three—in sumed to be gradual. Kounios, a man of matches, and a candle. They are told to this case, “apple” (“pineapple,” “crab with a shock of unruly wavy hair and an attach the candle to a piece of corkboard apple,” “apple sauce”). The subjects have affinity for rumpled button-up vests, had so that it can burn properly. Nearly ninety up to thirty seconds to solve the puzzle. been working with electroencephalogra- per cent of people pursue the same two If they come up with an answer, they phy, or EEG, which measures the waves strategies. They try to tack the candle di- press the space bar on the keyboard and of electricity produced by the brain by rectly to the board, which causes the can- say whether the answer arrived via in- means of a nylon hat filled with greased dle wax to shatter. Or they try melting the sight or analysis. When I participated in electrodes. (The device looks like a bulky candle with the matches, so that it sticks the experiment in Jung-Beeman’s lab, I shower cap.) Because there is no time to the board; but the wax doesn’t hold and found that it was surprisingly easy to delay with EEG, Kounios thought it the candle falls.