Editors: Spelling of Brion in the fourth paragraph is cq.
University of Colorado at Boulder researchers have identified neural signals in the brain that could lead to a better understanding of conditions like obsessive-compulsive disorder and Parkinson's disease.
The signals, pinpointed by the CU-Boulder team, predict whether people are biased to learn more from positive than negative outcomes of their decisions, according to Michael Frank, a research associate in the psychology department and lead author of the study.
"By showing that particular brain signals predict people's implicit tendencies to focus more on the positive than negative outcomes of their decisions, these findings also provide insight into the neural basis for optimism and pessimism," Frank said.
A paper on the subject by Frank, psychology Associate Professor Tim Curran and psychology research assistant Brion Woroch, all of CU-Boulder, appears in the Aug. 18 issue of the journal Neuron.
The findings were first predicted by a computer model developed by Frank that shows how different parts of the brain are engaged during reinforcement learning and decision making.
During the study, they attached electrodes to people's heads and recorded their brain signals while they performed tasks. They found that the tendency to pay more attention to mistakes was predicted by a signal coming from a section of the brain called the anterior cingulate cortex, according to Frank.
This signal known as the error-related negativity, or ERN, can be thought of as the neural equivalent of TV character Homer Simpson's 'Doh!', and was observed after people made mistakes in a computerized learning game, Frank said. But unlike Homer, people with large ERN signals actually learned more from their mistakes than those with small ERNs, who were better at learning from correct choices, he said.
The research also showed that when forced to make difficult decisions, such as those involving win-win or lose-lose situations, different brain signals were observed in the two types of learners.
People learning from positive decision outcomes had larger ERNs during win-win decisions, suggesting they had difficulty having to forgo one good choice for another. In contrast, those focused on their mistakes had larger ERNs during lose-lose decisions, when either choice was associated with negative outcomes, suggesting that they feel like everything they do is wrong, according to Frank.
Patients with obsessive-compulsive disorder are thought to have a dysfunctional error-monitoring system and hyperactive anterior cingulate, as if their brain is always telling them that they are making mistakes, so they repetitively perform corrective actions to try to reduce the error signals, he said.
"Using computer models together with neuroimaging can help us get a better understanding of how the healthy brain learns and acts, and of how this is altered in neurological conditions like obsessive-compulsive disorder," Frank said.
"The ultimate goal is to develop treatments that directly target the dysfunction without causing unwanted side effects," he said.