To buy or not to buy…shoppers base their decision on immediate pleasure—and pain
If you’re starting 2007 with a financial hangover—a large credit card bill from all your holiday shopping—then next year, you might want to consider paying with cash to reign in your spending. That’s one conclusion from a study on the neuroeconomics of shopping by MIT researcher Drazen Prelec and collaborators at Stanford and Carnegie Mellon University, published yesterday in Neuron.
The researchers used functional magnetic resonance imaging to map the brain activity of 26 male and female subjects as they shopped, with real cash, via a computer for small items like DVDs, games, and books. The results challenge the accepted economic model of decision-making.
The researchers found that as the subjects were deciding whether to buy or not, they displayed changes in brain activity in two opposing neural centers: one that anticipates the pleasure of buying a desired object, and another that registers the immediate pain of parting with cash. Neural circuits involved in assessing the long-term impacts of the decision weren’t active. Based on these changes, the researchers could accurately predict whether a subject would subsequently buy the item or not.
Current economic thinking is that consumers weigh the instant rewards of acquisition against the possibility of future gratification that comes with holding onto their money.
Instead, consumers’ buying decisions are influenced by more immediate effects—such as the loss of cash—rather than by long-term impacts, the researchers say.
This internal struggle may explain why people tend to overspend on credit cards. Putting it on plastic provides the rush of buying while deferring the discomfort of paying—at least for a month, that is. Pat McCaffrey
Dark matter could be even darker
Dark matter, the mysterious glue thought to hold galaxies together, may be even harder to spot than previously thought, a new study suggests.
The matter we see in the universe doesn’t supply enough gravitational pull to hold spinning galaxies together. So physicists have hypothesized for decades that unseen matter is keeping the universe together. They estimate that there’s five times as much dark matter in the universe as normal matter.
But dark matter is hard to detect since it doesn’t give off or reflect light. No one has spotted any dark matter particles yet, but physicists are intent on finding them. They have one class of particles in their scopes: WIMPs or weakly interacting massive particles.
Now physicists Daniel Feldman and Pran Nath at Northeastern University think there could be a new, unsuspected form of dark matter: extremely weakly interacting particles, or XWIMPs. In a paper with Boris Kors of CERN in Geneva, Switzerland, they show that these particles could interact with normal matter even more weakly than previously thought—at least 10 times less.
If dark matter is made of XWIMPS, then attempts now underway to directly detect dark matter particles could face an even bigger challenge than expected, the study says. Mason Inman
The heartbreak of posttraumatic stress
Veterans with symptoms of posttraumatic stress disorder (PTSD) are at a higher risk of heart disease as they age, according to a study from researchers at the Harvard School of Public Health and Boston University.
The researchers write that their study is the first to find a link between PTSD and cardiovascular disease, adding heart disease to the list of physical and psychiatric afflictions that can plague soldiers long after their military service ends.
Laura Kubzansky and colleagues examined the health records of nearly 2,000 veterans from the greater Boston area who were assessed in 1986 or 1990 for symptoms of PTSD. They identified 255 who experienced fatal or nonfatal heart attacks or chest pain in the following 10 to 15 years.
They found that for each PTSD symptom a subject had, his chances of heart disease increased by 20 percent, even after controlling for other possible risk factors like smoking, drinking, and depression.
The paper appears in the January issue of the Archives of General Psychiatry. Pat McCaffrey
