Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Monkeys found to wonder what might have been

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:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>