Advice vs. experience: Genes predict learning style

Apr 19, 2011

Researchers at Brown University have found that specific genetic variations can predict how persistently people will believe advice they are given, even when it is contradicted by experience.

The story they tell in a paper in the April 20 issue of the is one of the byplay between two that have different takes on how incoming information should influence thinking. The (PFC), the executive area of the brain, considers and stores incoming instructions such as the advice of other people (e.g., "Don't sell those stocks.") The striatum, buried deeper in the brain, is where people process experience to learn what to do (e.g., "Those stocks often go up after I sell them.")

Researchers including Michael Frank, assistant professor of cognitive, linguistic, and psychological sciences at Brown, have studied the striatum intensely, but have been curious about the effect that the advice-influenced PFC has on its function. It turns out that in a learning task, people are guided more by advice at the start. Their genes determine how long it takes before they let the lessons of experience prevail.

"We are studying how maintaining instructions in the prefrontal cortex changes the way that the striatum works," said lead author Bradley Doll, a graduate student in Frank's lab. "It biases what people learn about the contingencies they are actually experiencing."

In their experiment, the researchers studied people with and without genetic variations that affected the activity of the neurotransmitter dopamine in the PFC and striatum. A variation in a gene called COMT that affects dopamine in the PFC, for example, helps people remember and work with advice.

People with a variation on the gene DARPP-32 that affects the response to dopamine in the stratium allowed people to learn more quickly from experience when no advice was given, but also made them more readily impressionable to the bias of the PFC when instruction was given. Like a "yes man" who is flexible to a fault, the striatum would give more weight to experiences that reinforced the PFC's belief, and less weight to experiences that contradicted it. Researchers call this confirmation bias, which is ubiquitous across many domains, such as astrology, politics, and even science.

"People will distort what they experience to be perceived as more consistent with what they thought already," said Frank, who is also affiliated with the Brown Institute for Brain Science.

To conduct the experiment, the researchers recruited more than 70 people who gave saliva samples and then performed a computerized learning task. The subjects were shown symbols on a screen and asked to pick the "correct" one, which they had to learn via feedback. Because the feedback was probabilistic, it was impossible to choose the correct symbol on every trial, but subjects could learn over multiple trials which of the symbols were more likely to be correct.

For some symbols, subjects were given advice about which answer was more likely to be correct. Sometimes that advice was wrong. Ultimately the people with particular genetic variants were the ones who stuck with wrong advice the longest, and in a later test they were more likely to choose symbols that they were advised were correct over those that in reality had higher likelihood of being correct. Using a mathematical model, the researchers found that the extent of this confirmation bias on learning depended on their genes.

Tradeoffs of adaptability

It may seem like having the genes for a strong-willed prefrontal cortex and an overly obsequious striatum could make people dangerously oblivious to reality, but Frank said there's a good reason for brains to be hardwired to believe in advice: Advice is often right and convenient.

People inclined to follow instructions from others, albeit to varying degrees based on their genes, can make sensible decisions much more quickly than if they had to learn the right thing to do from experience. In some cases (e.g., "Danger: high voltage") experience is a very dangerous way to learn. But in other cases (e.g. "The cable guy should be there at 1 p.m." or "This slot machine pays off"), believing in advice for too long is just foolish.

"It's funny because we are telling a story about how these lead to maladaptive performance, but that's actually reflective of a system that evolved to be that way for an adaptive reason," Frank said. "This phenomenon of confirmation bias might actually just be a byproduct of a system that tries to be more efficient with the learning process."

Explore further: Know the brain, and its axons, by the clothes they wear

Related Stories

Gene variations can be barometer of behavior, choices

Jul 20, 2009

Researchers at Brown University and the University of Arizona have determined that variations of three different genes in the brain (called single-nucleotide polymorphisms) may help predict a person's tendency ...

The Protein for Quick Decision-Makers

Oct 26, 2009

(PhysOrg.com) -- Everyday, people are required to make decisions quickly and flexibly. In a flash, they must weigh up the advantages, disadvantages and possible consequences of their behaviour and coordinate it with the relevant ...

Why we learn more from our successes than our failures

Jul 29, 2009

(PhysOrg.com) -- If you've ever felt doomed to repeat your mistakes, researchers at MIT's Picower Institute for Learning and Memory may have explained why: Brain cells may only learn from experience when we ...

Dopamine-related drugs affect reward-seeking behavior

Apr 26, 2007

Drugs that adjust dopamine levels in the brain greatly affect how people react to success and failure, according to research that will be presented at the American Academy of Neurology’s 59th Annual Meeting in Boston.

Researchers find 'switch' for brain's pleasure pathway

Mar 22, 2006

Amid reports that a drug used to treat Parkinson's disease has caused some patients to become addicted to gambling and sex, University of Pittsburgh researchers have published a study that sheds light on what may have gone ...

Recommended for you

Know the brain, and its axons, by the clothes they wear

Apr 18, 2014

(Medical Xpress)—It is widely know that the grey matter of the brain is grey because it is dense with cell bodies and capillaries. The white matter is almost entirely composed of lipid-based myelin, but ...

Turning off depression in the brain

Apr 17, 2014

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Rapid whole-brain imaging with single cell resolution

Apr 17, 2014

A major challenge of systems biology is understanding how phenomena at the cellular scale correlate with activity at the organism level. A concerted effort has been made especially in the brain, as scientists are aiming to ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

WarRoom
not rated yet Apr 19, 2011
I think advice is a good shortcut, but like Reagan said, trust but verify. A lot of what's in textbooks is never revisited and a lot of common knowledge among folks is never updated. Most people are surprised or don't believe that China has the only operating MagLev train.
pauljpease
not rated yet Apr 20, 2011
Reminds of the recent article showing a difference in brain regions between liberals and conservatives. I'd like to see a mash up between these studies. I have a feeling that people who are predisposed to believe what they're told might be more common towards one end of that spectrum.

More news stories

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.