- People with anxiety have a stronger than normal desire to avoid negative consequences, and people with depression have a lower desire to approach the reward in the first place.
- Several parts of the brain are involved in this process: the anterior cingulate cortex, the prefrontal cortex, the striosomes or the orbifrontal cortex.
People with anxiety tend to adopt a more negative posture than others. The cognitive process involved remains unclear. A new research, published on June 30 in the journal Frontiers in Neuroscience, sheds light on what goes on in the brains of people with anxiety when they make a decision.
A new epidemic of anxiety
In previous research, negative mental states have been shown to upset the balance between the desire for a reward and the difficulties faced in getting there. This leads to more pessimistic decision making and avoidance. For example, scientists have found that people with anxiety have a stronger than normal desire to avoid negative consequences, and people with depression have a lower desire to approach the reward in the first place.
To understand how the brain integrates anxious feelings into decision-making, Japanese neuroscientists at Kyoto University synthesized studies conducted in recent years measuring the brains of rats and primates and linked these findings to the brain. human. “We are facing a new epidemic of anxiety, and it is important that we understand how our anxiety influences our decision making., says Ken-ichi Amemori, lead author of the study. There is a real need to better understand what is going on in the brain.
The anterior cingulate cortex in the center of the play
Previous studies have highlighted the role of neurons in the anterior cingulate cortex (ACC) as playing an important role in the decision-making process. CCA is also connected with other parts of the brain that play a role in integrating feelings into rational thought.
Through a study on monkeys, researchers identified groups of neurons that turned on or off depending on the size of the reward or punishment offered. Neurons associated with avoidance and pessimistic decision-making were particularly concentrated in pregenial CCA, a region linked to major depressive disorder and anxiety. Microstimulation of this area with a low-level electrical pulse, simulating the effects of anxiety, caused the monkeys to avoid the reward.
The striosomes have an unknown but important role
The scientists then looked for the connections of the pregenial CCA with other parts of the brain. They discovered interconnections with many parts of the prefrontal cortex at the front of the human brain, particularly associated with reasoning skills.
They also noted a strong connection with labyrinth-like structures known as striosomes. “The function of striosome structure has long been a mystery, but our experiences indicate that it is an important node connecting pessimistic decision-making with the brain’s reward system and dopamine regulation.”, Says Ken-ichi Amemori.
Orbitofrontal cortex also involved
Looking even closer, the team identified a connection between the striosomes and another more distant region: the orbitofrontal cortex, located at the front of the brain. This part is also known to be involved in cognition and decision making. In his experiments with primates, the researchers found a very similar influence of this region on the ape’s tendency to make pessimistic decisions. Oddly enough, the orbitofrontal cortex and the pregenial CCA also share many of the same connections with other parts of the brain.