Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dopamine key to learning likes and dislikes

05.11.2004


For those who have wondered why they like or dislike certain things, or how they decide what to order from a menu, a team of researchers at the University of Colorado at Boulder says it’s dopamine.



A CU-Boulder team studying Parkinson’s disease patients found strong evidence that dopamine in the brain plays a key role in how people implicitly learn to make choices that lead to good outcomes, while avoiding bad ones. The finding could help researchers understand more about how the brain works and could lead to a better understanding and treatment of brain disorders like schizophrenia, according to CU-Boulder psychology graduate student Michael Frank, who led the study.

A paper on the subject by Frank, CU-Boulder psychology Associate Professor Randall O’Reilly and Lauren Seeberger of the Colorado Neurological Institute’s Movement Disorders Center appears in the Nov. 5 issue of Science Express, an online version of Science magazine. Often people will get a "gut feeling" that allows them to make a choice depending on how often it was associated with positive outcomes in the past. But people with Parkinson’s disease often have difficulty making these kinds of choices, Frank said.


To understand why, they developed a computer model of the effects of Parkinson’s disease and the medications used to treat it in the brain. From this model they predicted that Parkinson’s patients would differ in their decision making depending on whether or not they were taking their medication, which they confirmed in a subsequent study.

They found that patients on their medication were overly influenced by positive outcomes, while those who were off their medication were more influenced by negative outcomes, according to Frank. "Because Parkinson’s disease is caused by lower levels of the brain chemical dopamine, and the medications increase concentrations of this chemical, these results provide strong evidence that dopamine levels play a critical role in developing our likes and dislikes," Frank said.

Much of what is known about the brain comes from studying diseases that affect it, according to O’Reilly. So to understand how healthy people learn from their decisions, it helps to determine the conditions where learning is degraded. "Studying Parkinson’s patients helps us to understand how healthy people learn, by showing us what’s going on under the hood," O’Reilly said. "It’s kind of like when your car makes a funny noise and you discover how the fan belt works. In this case we looked at a disease that has showed us more about dopamine’s role in the learning system of the brain."

Dopamine also plays a critical role in many other neurological conditions including attention deficit disorder, schizophrenia and drug addiction, so these findings may have broader implications, according to Frank. For example, by more precisely understanding the detailed effects of dopamine in the brain, drugs could be designed to more directly target beneficial actions, without as many unwanted side effects. "This research clearly showed that current Parkinson’s medications have undesirable side effects on learning and decision making," Frank said. Other researchers have documented a sudden onset of gambling episodes associated with patients taking these medications. These episodes may have been caused by the increased sensitivity to positive outcomes caused by the medications, together with an insensitivity to losses, he said. "When experiencing a loss, dopamine levels are normally low in the brain, and the medication may prevent this from happening," Frank said.

By exploring the effects of potential drugs on different brain areas and circuits, the computer model can be used to find drugs that restore dopamine balance without causing these or other side effects. Similar applications to ADD are also possible. Currently, ADD is treated with drugs such as Ritalin that cause more dopamine to remain available in the brain, but these drugs also may block certain forms of learning, causing unwanted side effects. "This work helps us understand how the brain learns from experience, and translates this learning into decisions, the kinds of decisions we make on a daily basis, often without much conscious thought," Frank said. "Understanding how this process works in detail may help in developing strategies to generally improve our learning and decision-making abilities."

Randall O’Reilly | EurekAlert!
Further information:
http://www.colorado.edu

More articles from Life Sciences:

nachricht Repairing damaged hearts with self-healing heart cells
22.08.2017 | National University Health System

nachricht Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>