Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Monkeys found to wonder what might have been

18.05.2009
Monkeys playing a game similar to "Let's Make A Deal" have revealed that their brains register missed opportunities and learn from their mistakes.

"This is the first evidence that monkeys, like people, have 'would-have, could-have, should-have' thoughts," said Ben Hayden, a researcher at the Duke University Medical Center and lead author of the study published in the journal Science.

The researchers watched individual neurons in a region of the brain called the anterior cingulate cortex (ACC) that monitors the consequences of actions and mediates resulting changes in behavior. The monkeys were making choices that resulted in different amounts of juice as a reward.

Their task was like the TV show "Let's Make a Deal" with the experimenters offering monkeys choices from an array of hidden rewards. During each trial, the monkeys chose from one of eight identical white squares arranged in a circle. A color beneath the white square was revealed and the monkey received the corresponding reward.

Over many weeks, the monkeys were trained to associate a high-value reward with the color green and the low-value rewards with other colors. After receiving a reward, the monkey was also shown the prizes he missed.

What the researchers saw was that neurons in the ACC responded in proportion to the reward -- a greater reward caused a higher response. They also found that these same neurons responded when monkeys saw what they missed. Most of these ACC neurons responded the same way to a real or imagined reward.

To measure how these responses might help the monkey to learn, the researchers kept the high reward in the same position 60 percent of the time, or moved it one position clockwise, so that a monkey could possibly notice and adapt to that pattern. The monkeys chose targets next to potential high-value targets more often than those next to low-value targets, (37.7 percent to 16.7 percent), which suggested that they understood the relationship between the high value target on the current trial and its likely location on the next trial. The monkeys learned the pattern and chose the high value more often than by a chance.

"It is significant to learn that the neurons have a dual role, because the monkey can only adapt his behavior when he gets information on both of those events, real and missed," said Michael Platt, Duke professor of neurobiology and evolutionary anthropology and senior author of the study.

People are much more likely to gamble if they see they could have won big by gambling in the past. Thus the researchers hypothesized that the monkeys would also select the target if it had offered a large reward on the previous trial and the monkey had missed it, and indeed, they observed this pattern. The effect may have reflected an increased willingness to switch to a new target, because the likelihood of switching increased with larger missed rewards, they noted.

"This was not merely a function of the high-value targets holding a positive association for the monkey," Platt said.

The monkeys' ACC neurons signaled missed reward information, and used a coding scheme in the brain that was similar to the coding used to signal real outcomes, Platt said. The researchers suspect that these neurons actually helped the monkeys to make better choices in the future.

John M. Pearson, Ph.D., of Duke Neurobiology was also an author of the paper. The study was supported by a post-doctoral fellowship from the National Institute on Drug Abuse, a Neuroscience Education Institute grant, and the Duke Institute for Brain Sciences.

Mary Jane Gore | EurekAlert!
Further information:
http://www.duke.edu

More articles from Studies and Analyses:

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>