When our curiosity is piqued, learning can be a snap and recalling the new information comes effortlessly. But when it comes to things we don’t care about—the recipe to that “delicious” holiday fruitcake or, if we’re not really into football, the results of this year’s San Diego County Credit Union Poinsettia Bowl—the new information rarely sticks.
To probe why this might be so, neuroscientists Charan Ranganath and Matthias Gruber, and psychologist Bernard Gelman, all at the University of California at Davis, devised a multi-step experiment to explore which regions of the brain are activated when we are curious, and how curiosity enhances our ability to learn and remember.
The team recruited 19 students and asked them to rate more than 100 trivia questions. The students were encouraged to rate how confident they were that they knew the answer and their level of curiosity.
The scientists next measured the brain activity of each student using an imaging technique called Functional Magnetic Resonance Imaging (fMRI). While lying in the scanner each participant was shown trivia questions that stumped them, some of which piqued their curiosity and others that didn’t. As the students anticipated each answer, a photograph of a stranger flashed onto the screen. When the photo disappeared, a few seconds passed before the answer appeared. This sequence was repeated 112 times.
Each student left the MRI scanner and took a quiz on the answers to the trivia questions and recall of the faces. When Ranganath’s team scored the tests, they found the students recalled 71% of the answers that really piqued their curiosity compared to 54% of the answers that didn’t . That, of course, wasn’t surprising . When something interests us, we are more likely to remember it.
The intriguing result came when the researchers tested the students’ ability to recall the faces. They found the students’ ability to recognize faces was significantly higher during moments of great curiosity than during times of low curiosity. The team moved ahead to a second behavioral experiment and showed that the beneficial effect of extreme curiosity on trivia and face recollection persisted a day later. This indicates that the effects of curiosity, far from fleeting, help to build lasting memories.
These results suggest a curious state of mind primes us to learn not just the things that interest us, but it helps us recall the peripheral information that we notice during our moments of wonder. To determine which brain activity might explain this behavior, the team went back and studied the fMRI data for leads.
Ranganath’s team discovered that as the students grew curious, activity increased in two brain regions (the substantia nigra/ventral tegmental area and the nucleus accumbens) that are associated with reward and motivation. The level of curiosity seemed to control activity in these areas like a dimmer switch. During times of great curiosity, these two brain regions were very active. During moments of disinterest or even boredom, these areas shifted into low gear.
Another interesting twist came in the hippocampus, an area of the brain involved in memory formation, where activity ramped up before the trivia answers appeared. The increased activity in the hippocampus helped to predict whether the student would remember the answer. Students who showed more activity in this substantia nigra/ventral tegmental area/hippocampus/nucleus accumbens circuit tended to remember faces better when these were shown during the anticipation period. This suggests a high state of curiosity stimulates interactions between neural pathways involved in motivation and memory. These interactions may make the brain more conducive to learning, boosting our ability to process even the nearby uninteresting stuff.
I’m very curious to see what experiments these researchers perform next.
 The wick in the candle of learning: epistemic curiosity activates reward circuitry and enhances memory. Kang MJ, Hsu M, Krajbich IM, Loewenstein G, McClure SM, Wang JT, Camerer CF. Psychol Sci. 2009 Aug;20(8):963-73.
Charan Ranganath’s Dynamic Memory Lab, University of California, Davis
NIH support: National Institute of Mental Health