Monitor on Psychology - October 2011 - (Page 59)

Photos.com similar to the Wisconsin Card Sort Test, the researchers presented monkeys with two icons on a computer screen each showing a line and a shape, and the monkey had to touch one of the icons and avoid touching the other one. However, the “rule” was then changed so that the icon that was previously wrong became correct and vice versa. Following small lesions in the orbitofrontal cortex, the monkeys did not adapt to the new rule, and persisted in choosing the formerly rewarded icon, the researchers found. This tendency struck Robbins and his colleagues as similar to that of people with obsessive-compulsive disorder. So, in a study in press in Neuroimage, they compared the richness of the orbitofrontal cortex connections in the brains of people with OCD and those with a history of stimulant use, and found that both groups had reduced connectivity in the ventromedial and superior areas of the orbitofrontal cortex. “In both cases, this reduction in connectivity was negatively correlated with compulsive behavior,” said Robbins. “The more compulsive they were, the less connectivity they had.” In another study, in press in Biological Psychiatry, Robbins and his colleagues showed that activity in the striatum, a brain region connected to the orbitofrontal cortex, was reduced during “reversal learning” in stimulant-dependent individuals and was also related to their cognitive inflexibility. Researchers ameliorated this loss of activity and cognitive inflexibility by giving stimulant-dependent participants pramipexole, which acts like dopamine in the brain and is often used to control the symptoms of Parkinson’s disease. Impulsivity People who are more impulsive to begin with are probably more likely to try drugs, said Robbins. Stimulants, however, seem to amplify that trait, according to a study he conducted with colleagues published in Biological Psychiatry (Vol. 68, No. 8). They found that non-drug abusing siblings of cocaine addicts tended to score higher than average on the Barratt Impulsiveness Scale, agreeing with statements such as “I do things without thinking” and “I change jobs often.” The cocaine-addicted study participants scored even higher. Robbins and his colleagues further tested chronic stimulant users’ and their siblings’ impulsive tendencies by giving them the stop signal reaction time test — a game where a computer prompts you to press a particular key, but as soon as you get into the rhythm of pressing it, a beep sounds, telling you to cancel your response. Both stimulant drug users and their siblings were much slower to respond to the beep than the control group. “Their siblings clearly have some sort of predisposition to impulsivity parallel to their drug-taking siblings, which means that the impulsivity can’t simply be a result of drug abuse and is a personality trait which may you vulnerable to stimulant abuse. Of course, abusing the drug probably makes things worse, possibly through toxic effects in the prefrontal cortex circuits that mediate self-control,” Robbins said. Taken together, the findings suggest that stimulant drugs may produce changes in people’s prefrontal cortices that make them more likely to continue using drugs, said Robbins. However, new medications may help people at the early stages of addiction regain control of their lives. n 59 OCTOBER 2011 • MONITOR ON PSYCHOLOGY http://photos.com

Table of Contents for the Digital Edition of Monitor on Psychology - October 2011

Monitor on Psychology - October 2011
President’s Column
Subtle and stunning slights
Contents
From the CEO
Live science on the showroom floor
Zimbardo re-examines his landmark study
Ready, set, mentor
Attention students and ECPs: Self-care is an ‘ethical imperative’
Suicide risk is high among war veterans in college, study finds
Psychotherapy is effective and here’s why
From toilet to tap: getting people to drink recycled water
What’s ahead for psychology practice?
A push for more accountability is changing the accreditation process
Peer, parental support prove key to fighting childhood obesity
Popular media’s message to girls
Bullying may contribute to lower test scores
A consequence of cuckoldry: More (and better) sex?
Manatees’ exquisite sense of touch may lead them into dangerous waters
Building a better tomato
How will China’s only children care for their aging parents?
‘Spice’ and ‘K2’: New drugs of abuse now on the market
Many suspects don’t understand their right to remain silent
In Brief
Boosting minority achievement
Where’s the progress?
And social justice for all
Helping new Americans find their way
Segregation’s ongoing legacy
A new way to combat prejudice
Retraining the biased brain
Suppressing the ‘white bears’
How to eat better — mindlessly
Protect your aging brain
Must babies always breed marital discontent?
Outing addiction
Flourish 2051
The danger of stimulants
Keys to making integrated care work
Is technology ruining our kids?
Facebook: Friend or foe?
The promise of Web 3.0
NIMH invests in IT enhanced interventions
Science Directions
Science Directions
PsycAdvocates work to safeguard key programs
The psychology of spending cuts
APA’s strategic plan goes live
Visionary leaders
Bravo!
Vote on bylaws amendments

Monitor on Psychology - October 2011