Curiosity improves memory by tapping into the brain’s reward system

The brain’s dopamine reward circuitry fires up when people are curious about finding answers, making learning more effective



Brain scans of college students have shed light on why people learn more effectively when their curiosity is piqued than when they are bored stiff.

Researchers in the US found evidence that curiosity ramped up the activity of a brain chemical called dopamine, which in turn seemed to strengthen people’s memories.

Students who took part in the study were better at remembering answers to trivia questions when they were curious, but their memories also improved for unrelated information they were shown at the same time.

The findings suggest that while grades may have their place in motivating students, stimulating their natural curiosity could help them even more.

Charan Ranganath, a neuroscientist at the University of California, Davis, said curiosity seemed to be piqued when people had some knowledge of a subject but were then faced with a gap in their understanding. “We think curiosity is the drive to fill that gap. It’s like an itch you just have to scratch,” he said.

Matthias Gruber, a colleague of Ranganath’s who led the study, asked students to work through a series of trivia questions. He then had them rate how confident they were that they knew the correct answer and how curious they were to find out. He then created bespoke lists of questions for each student that left out those they already knew the answers to. The remaining questions ranged from ones the students were highly curious about to others they found totally boring.

Gruber then used an fMRI scanner to monitor each student’s brain while their list of questions appeared one after another on a screen. After each question they faced a 14-second wait during which a random face flashed up for two seconds. The answer to the trivia question then appeared on the screen before the next question flashed up.

The scans revealed that when people were more curious, brain activity rose in regions that transmit dopamine signals. The neurotransmitter is intimately linked to the brain’s reward circuitry, suggesting that curiosity taps into the same neural pathways that make people yearn for chocolate, nicotine and a win at the races.

“When we compare trials where people are highly curious to know an answer with trials where they are not, and look at the differences in brain activity, it beautifully follows the pathways in the brain that are involved in transmitting dopamine signals,” said Ranganath. “The activity ramps up and the amount it ramps up is highly correlated with how curious they are.”

In memory tests an hour later, the students were better at remembering the answers to questions they were curious about. On average, they remembered 35 of 50 answers when they were curious, compared with 27 out of 50 when they were not.

The students also did better at recognising the faces that had flashed up on the screen when they were waiting for the answer to a question that made them curious. The improvement was slight, at 42% versus 38% for faces that flashed up before questions the students found boring.

The study showed that – as expected – students had better memories when their curiosity was piqued. To find out if the effect was brief or longer-lasting, they ran another series of tests.

Gruber invited a different group of students into the lab and put them through the same regime of reading trivia questions, watching faces flash up, and seeing the answers. This time Gruber tested their memories a full day later. The students still fared better when they had been curious, suggesting that the improvement in memory was more than momentary.

“There are times when people feel they can take in a lot of new information, and other times when they feel their memories are terrible,” said Ranganath. “This work suggests that once you light that fire of curiosity, you put the brain in a state that’s more conducive to learning. Once you get this ramp-up of dopamine, the brain becomes more like a sponge that’s ready to soak up whatever is happening.”

Ranganath said the findings are in line with theories that give dopamine a key role in stabilising or consolidating memories. The research is published in the journal, Neuron.

Guillén Fernández at the Donders Centre for Cognitive Neuroimaging in the Netherlands said: “Understanding the mechanistic underpinning of how we learn is of utmost importance if we want to optimise knowledge acquisition in education. “The brain is the most individual organ we have. The authors of this report show nicely that individual differences in curiosity are associated with differential abilities to learn new information.”

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