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 Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

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: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>