Bob - This week for the Naked Scientists, we're bringing you stories from the annual meeting of our organisation, the American Association for the Advancement of Science, going on right now in San Francisco, California. I'm going to tell you why smart kids choke on mathematics exams, but first, Chelsea has this story about how drugs work in your brain.
Chelsea - If you want to know what it's like to be addicted to cocaine, you might imagine being really, really hungry. That's according to Friday's presentation by neuroscientist Nora Volkow, director of the National Institute on Drug Abuse. She found that the brains of cocaine addicts release the pleasure chemical dopamine when exposed to drug cues, like images of people using drugs or drug paraphernalia. She says that's the same thing that happens in the brains of food-deprived people exposed to food cues, but to a lesser degree.
Nora - What drugs are doing is taking advantage of circuits that are there for a very specific purpose. The circuits that are tapped by drugs are those that will ensure that we will do behaviours that are indispensable such as eating.
Chelsea - And she says that's why addicts can't resist the urge to get high any more than a starving person could resist the urge to eat.
Bob - Thanks, Chelsea. The best mathematics students are also the most susceptible to choking under pressure. This according to the work of University of Chicago psychologist Sian Beilock, who spoke here yesterday. Her team found that top students rely on their superior working memory to solve complex problems. But average students often fall back on less accurate shortcuts, like estimation.
Sian - Under pressure, however, our higher working memory individuals didn't continue with the complex algorithm. They actually switched to the shortcut. So their performance looked like the lower working memory individuals' under pressure, and now we have some idea why this is the case.
Bob - She said that because pressure appears to sabotage working memory, high-stakes exams may not accurately identify the best and the brightest.
Chelsea - Thanks, Bob. Next time we'll be back in Washington, DC, bringing you stories from our side of the Atlantic. Until then, I'm Chelsea Wald.
Bob - And I'm Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists.