Research Roundup

Marijuana users are bad card players

Habitual marijuana smokers may suffer from diminished decision-making abilities, suggests research by Wake Forest neuroscience student Michael Wesley.

With his adviser, Linda Porrino, PhD, Wesley observed 14 regular marijuana users and 11 controls using fMRI scans and the Iowa Gambling Task, a test that uses four decks of cards—two that yielded large monetary rewards and two with small monetary rewards—to gauge decision-making.

The chronic marijuana users, who smoked an average of twice a day for seven years, were slow to learn that the deck with the small gains tended to provide more money over the long haul. As they lost money, the smokers' brains also showed less activity in the area associated with decision-making than the brains of the nonsmokers.

Wesley believes that the reason chronic users failed to develop successful decision- making strategies is because they have a blunted response, behaviorally and functionally, to information about losses.

For his dissertation, Wesley will continue working with chronic marijuana users to understand if poor decision-making feeds a desire to return to the drug.


Behind the wheel, ADHD may be as dangerous as alcohol

Driving under the influence of alcohol is clearly dangerous, but new research by University of Kentucky doctoral candidate Jessica Weafer finds that attention-deficit hyperactivity disorder (ADHD) may be similarly perilous. And the combination of ADHD and alcohol use may be especially potent—and common.

"Alcohol abuse is so highly prevalent in adults and young adults with ADHD," says Weafer, and she believes that the increased risk for alcohol abuse in adults with ADHD may be because they react differently to the drug.

Weafer used a driving simulator to test the driving ability in adults with ADHD and a control group of people without ADHD. She found that adults with ADHD performed significantly worse than the controls at all levels of intoxication—from sober to blood alcohol concentrations of .08 percent. Weafer also asked the research participants about their perceived levels of intoxication and ability to drive. She found that despite performing significantly worse than controls, adults with ADHD felt they were less intoxicated and better able to drive.


Depressed people may not have an accurate outlook

Past research suggests that depressed people are more accurate in their predictions of the likelihood of future events, while non-depressed people tend to see the world in a sunny but inaccurate light. But a new study by Abby Adler, a doctoral psychology student at Ohio State University, found that depressed people tend to see the world in an equally inaccurate, pessimistic light.

Adler asked 87 undergraduate students whether positive and negative events—such as a party invitation or fight with a family member—were likely to occur. She also asked the students how a person close to them would rate their personality and how well they would score on an IQ test.

"Some people say that depression is associated with more accurate predictions, which isn't necessarily a bad thing," says Adler.

Adler found otherwise, when she compared participants' predicted and actual IQ scores, as well as when she compared a close friend or family member's assessment of participants' personalities with the test-subjects' own self-estimates. Overall, she found that highly depressed students underestimated their character and intelligence and expected bad things to happen, which generally did not come to pass.

For her dissertation, Adler will develop new ways to help people with depression combat their pessimism and rumination and perhaps give them a more positive—and more accurate—perspective on life.


Young immigrant students fall behind, but not for long

Kindergarten is a new and often intimidating experience for any child, but school can be even more daunting for children who do not speak the same language as their instructors. That's why George Mason University psychology student Jessica Johnson De Feyter is studying the social and cognitive abilities that help young children from low-income, immigrant families make the transition to a new school.

She's using data from 2,200 second-grade students assessed by the Miami School Readiness Project, a collaboration among Florida International University, the Early Learning Coalition of Miami-Dade and George Mason University, which gauges the school readiness of children from low-income families in Miami. De Feyter found that first- and second-generation immigrant children lag behind their peers in cognitive and language skills but test higher on socio-emotional skills, such as playing well with peers and respecting teachers. De Feyter believes they have better social skills because of the emphasis many immigrant parents place on initiative, respect for adults and peer relationships.

She suggests that socio-emotional skills help immigrant children catch up with their peers because positive interactions with teachers provide them with a wealth of learning opportunities. De Feyter's next step is to understand whether the socio-emotional factors that allow students to level the academic field are a result of parental emphasis on education or because students overcome language barriers.

By Jared C. Clark
gradPSYCH Staff