The Addicted Brain
UC Berkeley researchers recently released findings that could be critical to understanding the addicted brain. The team led by Jordan Wallis, an associate professor of psychology and neuroscience at UC Berkeley, examined how activity in two specific areas of the brain affects our ability to make decisions. Earlier research had demonstrated that individuals with damage to those parts of the frontal brain had impaired decision-making skills. While the subjects appeared normal, they continually made poor decisions that wreaked havoc on their lives. A similar phenomenon has been observed in those with chronic substance abuse issues. Dr. Wallis wanted to see if a malfunction in the brain’s circuitry caused these people to consistently make choices that fed their addiction in spite of the severe negative consequences.
They discovered that the orbitofrontal region cortex regulates neural activity depending on the significance of a decision. This enables us to easily switch between making critical decisions, such as accepting a job, and trivial ones, such as what to eat for dinner. The neural activity of addicts and those with brain damage to those areas, however, did not vary with the gravity of the decision. This could hinder someone’s ability to engage his or her brain in order to make a sound choice.
They also learned that when the anterior cingulate cortex functions properly we quickly learn whether our decisions match our expectations. For example, if we eat a food that makes us sick, we do not eat it again. If you have a malfunctioning anterior cingulate cortex, however, these signals are missing, and you do not learn from your mistakes. Basically, these two regions of our brain control how we assess the decisions we make. When those areas are compromised, we cannot properly evaluate the impact of our decisions, determine the level of risk, or retain whether it was a successful choice or not. Thus, a cycle of poor decision-making is born.
We have known for a long time that addiction actually alters the brain’s circuitry and affects the brain’s reward system. Drastically reduced dopamine levels and misfiring neurotransmitters are key components of addiction. We also knew that substance abuse compromised our ability to control our desires and emotions, and decision-making was an undefined part of that. Studies such as Dr. Wallis’s reinforce the idea that addiction is indeed a brain disease rooted as much in biology as in psychology. Understanding the addicted brain will hopefully lead to new ways of preventing and treating addiction.