Brain scans show we take risks because we can't stop ourselves

A new study correlating brain activity with how people make decisions suggests that when individuals engage in risky behavior, such as drunk driving or unsafe sex, it's probably not because their brains' desire systems are too active, but because their self-control systems are not active enough.

This might have implications for how health experts treat mental illness and addiction or how the legal system assesses a criminal's likelihood of committing another crime.

Researchers from The University of Texas at Austin, UCLA and elsewhere analyzed data from 108 subjects who sat in a magnetic resonance imaging (MRI) scanner—a machine that allows researchers to pinpoint brain activity in vivid, three-dimensional images—while playing a video game that simulates risk-taking.

The researchers used specialized software to look for patterns of activity across the whole brain that preceded a person's making a risky choice or a safe choice in one set of subjects. Then they asked the software to predict what other subjects would choose during the game based solely on their brain activity. The software accurately predicted people's choices 71 percent of the time.

"These patterns are reliable enough that not only can we predict what will happen in an additional test on the same person, but on people we haven't seen before," said Russ Poldrack, director of UT Austin's Imaging Research Center and professor of psychology and neuroscience.

http://medicalxpress.com/news/2014-02-brain-scans.html

Proceedings of the National Academy of Sciences: "Predicting risky choices from brain activity patterns"