Extroverts have more sensitive brain-reward system

July 11, 2013 by Karene Booker, Cornell University
Brain diagram. Credit: dwp.gov.uk

Extroverts may be more outgoing and cheerful in part because of their brain chemistry, reports a study by Cornell neuroscientists.

People's brains respond differently to rewards, say the . Some people's brains release more of the , which ultimately gives them more reasons to be excited and engaged with the world, says Richard Depue, professor of human development in the College of Human Ecology, who co-authored the study with graduate student Yu Fu.

Their study, published in Frontiers in Human Neuroscience (Vol. 7) in June, sheds new light on how differences in the way the brain responds to reward translate into extraverted behavior, the authors say.

"Rewards like food, sex and social interactions as well as more abstract goals such as money or getting a degree trigger the release of dopamine in the brain, producing positive emotions and feelings of desire that motivate us to work toward obtaining those goals. In extroverts, this dopamine response to rewards is more robust so they experience more frequent activation of strong positive emotions," Depue says.

"Dopamine also facilitates memory for circumstances that are associated with the reward. Our findings suggest this plays a significant role in sustaining extroverted behavior," Depue adds. "The extroverts in our study showed greater association of context with reward than introverts, which means that over time, extroverts will acquire a more extensive network of reward-context memories that activate their brain's reward system."

Over a week, the researchers engaged 70 young – a mix of introverts and extroverts according to a standard – in a set of laboratory tasks that included viewing brief video clips of several aspects of the lab environment. On the first four days, some participants received a low dose of the stimulant (MP), also known as Ritalin, which triggers the release of dopamine in the brain; the others received either a placebo or MP in a different lab location. The team tested how strongly participants associated contextual cues in the lab (presented in video clips) with reward (the dopamine rush induced by MP) by assessing changes in their working memory, motor speed at a finger-tapping task and positive emotions (all known to be influenced by dopamine).

Participants who had unconsciously associated contextual cues in the lab with the reward were expected to have greater dopamine release/ activation on day 4 compared with day 1 when shown the same video clips. This so-called "associative conditioning" response is exactly what the team found in the extroverts. The extroverts strongly associated the lab context with reward feelings, whereas the introverts showed little to no evidence of associative conditioning.

"At a broader level, the study begins to illuminate how individual differences in brain functioning interact with environmental influences to create behavioral variation. This knowledge may someday help us to understand how such interactions create more extreme forms of emotional behavior, such as personality disorders," says Depue.

The study, "On the Nature of Extraversion: Variation in Conditioned Contextual Activation of Dopamine-Facilitated Affective, Cognitive and Motor Processes," was funded in part by the National Institute of Mental Health.

Explore further: Brain imaging shows how prolonged treatment of a behavioral disorder restores a normal response to rewards

More information: www.frontiersin.org/Human_Neur … nhum.2013.00288/full

Related Stories

Brain imaging shows how prolonged treatment of a behavioral disorder restores a normal response to rewards

June 28, 2013
Attention-deficit/hyperactivity disorder (ADHD) is characterized by abnormal behavioral traits such as inattention, impulsivity and hyperactivity. It is also associated with impaired processing of reward in the brain, meaning ...

Reward linked to image is enough to activate brain's visual cortex

March 21, 2013
Once rhesus monkeys learn to associate a picture with a reward, the reward by itself becomes enough to alter the activity in the monkeys' visual cortex. This finding was made by neurophysiologists Wim Vanduffel and John Arsenault ...

Taste of beer, without effect from alcohol, triggers dopamine release in the brain

April 15, 2013
The taste of beer, without any effect from alcohol itself, can trigger dopamine release in the brain, which is associated with drinking and other drugs of abuse, according to Indiana University School of Medicine researchers.

Pleasure response from chocolate: You can see it in the eyes

June 24, 2013
The brain's pleasure response to tasting food can be measured through the eyes using a common, low-cost ophthalmological tool, according to a study just published in the journal Obesity. If validated, this method could be ...

New brain research suggests eating disorders impact brain function

July 11, 2011
Bulimia nervosa is a severe eating disorder associated with episodic binge eating followed by extreme behaviors to avoid weight gain such as self-induced vomiting, use of laxatives or excessive exercise. It is poorly understood ...

Socially isolated rats are more vulnerable to addiction, report researchers

January 23, 2013
Rats that are socially isolated during a critical period of adolescence are more vulnerable to addiction to amphetamine and alcohol, found researchers at The University of Texas at Austin. Amphetamine addiction is also harder ...

Recommended for you

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.