The study enhances scientists' understanding of how the brain works in healthy and unhealthy individuals, according to the researchers.
"This discovery has general implications in understanding how the brain processes information to help us make good decisions and to learn from our mistakes," says senior author Geoffrey Schoenbaum, M.D., Ph.D., adjunct professor at the University of Maryland School of Medicine and senior investigator and chief of the Cellular Neurobiology Research Branch at NIDA. "Understanding more about the orbitofrontal cortex also is important for understanding disorders such as addiction that seem to involve maladaptive decision-making and learning. Cocaine in particular seems to have long-lasting effects on the orbitofrontal cortex. One aspect of this work, which we are pursuing, is that perhaps some of the problems that characterize addiction are the result of drug-induced changes in this area of the brain."
The scientists are continuing their research, examining the specific coding of the neurons in the orbitofrontal cortex during this process, as well as the effects that drugs of abuse have upon this area of the brain.
"Drug addiction is marked by severe deficits in judgment and bad decision-making on the part of the addict," says Dr. Jones. "We believe that drugs, particularly cocaine, affect the orbitofrontal cortex. They coerce the system and hijack decision-making."
The researchers examined the orbitofrontal cortex's role in value-guided behavior. The brain assigns two different types of values to behaviors and choices. Cached value is a value that is learned during prior experience. Inferred value happens on the spur of the moment, considering the entire model of rewards and consequences.
"Cached value is stored during prior experience, says Dr. Jones. "For example, you learn your route home on your commute through experience the habit of how you get home. You tur
|Contact: Karen Robinson|
University of Maryland Medical Center