While some scientists discount the existence of a sixth sense for danger, new research from Washington University in St. Louis has identified a brain region that clearly acts as an early warning system -- one that monitors environmental cues, weighs possible consequences and helps us adjust our behavior to avoid dangerous situations.

　　"Our brains are better at picking up subtle warning signs than we previously thought," said Joshua Brown, Ph.D., a research associate in psychology in Arts & Sciences and co-author of a study on these findings in the Feb. 18 issue of the journal Science.

　　The findings offer rigorous scientific evidence for a new way of conceptualizing the complex executive control processes taking place in and around the anterior cingulate cortex (ACC), a brain area located near the top of the frontal lobes and along the walls that divide the left and right hemispheres.

　　"In the past, we found activity in the ACC when people had to make a difficult decision among mutually exclusive options, or after they made a mistake," Brown said. "But now we find that this brain region can actually learn to recognize when you might make a mistake, even before a difficult decision has to be made. So the ACC appears to act as an early warning system -- it learns to warn us in advance when our behavior might lead to a negative outcome, so that we can be more careful and avoid making a mistake."

　　The ACC has been the focus of intensive scientific research in recent years because it plays a critical role in the brain's processing of especially complex and challenging cognitive tasks. Abnormalities in the region are closely associated with a host of serious mental problems, including schizophrenia and obsessive-compulsive disorder.

　　By providing a clearer picture of the cognitive mechanisms by which we self monitor and control our behavior, the study is an important step in efforts to develop more effective treatments for mental illness. It also provides a new way of understanding inappropriate behaviors that often accompany mental illnesses.

　　"Our results suggest how impairment of the ACC mechanisms in schizophrenia can lead to breakdowns in the early warning system, so that the brain fails to pre-empt or control inappropriate behavior," Brown said. "On the other hand, in individuals with obsessive-compulsive disorder, the ACC might warn of an impending problem even when no problem is imminent."

　　"Interestingly, we also found evidence that the same neurotransmitter involved in drug addiction and Parkinson's disease, namely dopamine, seems to play a key role in training the ACC to recognize when to send the early warning signal," he added.

　　Known to be an important component of the brain's executive control system, the ACC is believed to help mediate between cold, hard, fact-based reasoning and emotional responses, such as love, fear or anticipation.