Featured Research

from universities, journals, and other organizations

Cocaine Abuse Blunts Sensitivity To Monetary Reward

Date:
November 12, 2007
Source:
DOE/Brookhaven National Laboratory
Summary:
New measurements of brain activity confirm that cocaine-addicted individuals have compromised sensitivity to monetary rewards. This altered sensitivity may help explain why some drug-addicted individuals are unable to modify their drug-taking behavior, even in the face of well-understood negative consequences and/or positive incentives for behavioral change.

Brookhaven neuropsychology study coordinator Thomas Maloney (rear) and Stony Brook University graduate student Muhammad Parvaz (front) demonstrate the setup for measuring event-related potentials with postdoc Jose Trigo Diaz posing as a research subject.
Credit: Image courtesy of DOE/Brookhaven National Laboratory

New measurements of brain activity in individuals addicted to cocaine confirm that addicted individuals have compromised sensitivity to monetary rewards.

Related Articles


"This altered sensitivity to reward may help explain why some drug-addicted individuals are unable to modify their drug-taking behavior, even in the face of well-understood negative consequences and/or positive incentives for behavioral change," said Rita Goldstein, who runs the neuropsychoimaging lab at the U.S. Department of Energy's Brookhaven National Laboratory where the work was done. Muhammad A. Parvaz, a Stony Brook University graduate student working with Goldstein, presented the findings at the Society for Neuroscience annual meeting in San Diego on November 7, 2007.

The researchers studied 18 current cocaine users and 18 age-matched control subjects. They outfitted each subject with a cap of electrodes to measure brain activity after instructing the subjects to press or not press a button in response to certain visual prompts. During the task, subjects were told they could earn various amounts of money for fast and accurate performance.

The scientists were specifically interested in the P300 component of the brain waves "time locked" to the task (known as Event-Related Potentials). The P300, a positive voltage potential occurring at a latency of 300 milliseconds after presentation of a novel or meaningful stimulus, has been shown to be blunted in individuals addicted to alcohol and their offspring. The current study demonstrates, for the first time, a blunted P300 response to a commonly occurring and generalized abstract reward - money - in cocaine-addicted individuals with recent cocaine use.

The findings: In healthy control subjects, the P300 response was significantly higher and both accuracy and speed of performance were significantly better and faster, respectively, when a monetary reward was offered compared with when the reward was absent (45 vs. 0 cents). These responses to money in both brain and behavioral measures - and their interdependence - were reduced in cocaine-addicted individuals. In addition, those who had used cocaine most frequently during the year preceding the study were the least able to improve their behavioral performance in response to monetary rewards.

Interestingly, these results could not be attributed to decreased task engagement in the cocaine users, who instead reported being more interested in the task than the control subjects. It is possible that this heightened interest could be attributed to recent cocaine use, which was documented in all cocaine-using subjects in this study by positive urine screening tests.

"So despite greater self-reported interest, cocaine users did not respond faster or more accurately and their brain activity did not change in response to monetary reward to the same degree as in the healthy control subjects," Parvaz said.

These results confirm findings from earlier studies conducted in Goldstein's lab that used functional magnetic resonance imaging (fMRI) to demonstrate a similar compromise in neural sensitivity to monetary reward in cocaine addiction.

"Individuals with such blunted neural and behavioral sensitivity to rewards may have a particularly difficult time responding to abstract incentives designed to motivate behavioral changes - especially when outside of a structured treatment environment or when rewards are not readily available or clearly contingent on behavior," Goldstein said.

"It would be interesting to see if there are any differences between the cocaine users studied here, who were not seeking treatment, and those in treatment or abstinent for longer periods of time," Parvaz suggested. Such a comparison would allow the researchers to determine whether recovery of sensitivity to reward can be expected, and assess the time frame for such recovery. The researchers may also extend the study to see if their findings can be generalized to negative reinforcement, such as the loss of money.

This research was funded by: the Office of Biological and Environmental Research (OBER) within the U.S. Department of Energy's Office of Science; the National Institute on Drug Abuse; Laboratory Directed Research and Development funding from OBER; a Young Investigator Award from NARSAD (a mental health research association); a Stony Brook University/Brookhaven National Laboratory seed grant; the National Institute on Alcohol Abuse and Alcoholism; and by Stony Brook University's General Clinical Research Center.


Story Source:

The above story is based on materials provided by DOE/Brookhaven National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

DOE/Brookhaven National Laboratory. "Cocaine Abuse Blunts Sensitivity To Monetary Reward." ScienceDaily. ScienceDaily, 12 November 2007. <www.sciencedaily.com/releases/2007/11/071107160233.htm>.
DOE/Brookhaven National Laboratory. (2007, November 12). Cocaine Abuse Blunts Sensitivity To Monetary Reward. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2007/11/071107160233.htm
DOE/Brookhaven National Laboratory. "Cocaine Abuse Blunts Sensitivity To Monetary Reward." ScienceDaily. www.sciencedaily.com/releases/2007/11/071107160233.htm (accessed October 25, 2014).

Share This



More Mind & Brain News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Academic Scandal Shocks UNC

Academic Scandal Shocks UNC

AP (Oct. 23, 2014) A scandal involving bogus classes and inflated grades at the University of North Carolina was bigger than previously reported, a new investigation found. (Oct. 23) Video provided by AP
Powered by NewsLook.com
Working Mother Getaway: Beaches Turks & Caicos

Working Mother Getaway: Beaches Turks & Caicos

Working Mother (Oct. 22, 2014) Feast your eyes on this gorgeous family-friendly resort. Video provided by Working Mother
Powered by NewsLook.com
What Your Favorite Color Says About You

What Your Favorite Color Says About You

Buzz60 (Oct. 22, 2014) We all have one color we love to wear, and believe it or not, your color preference may reveal some of your character traits. In celebration of National Color Day, Krystin Goodwin (@kyrstingoodwin) highlights what your favorite colors may say about you. Video provided by Buzz60
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins