In a constantly changing world, animals, including humans, need to quickly adapt to their environment and make decisions that lead to the best outcomes. This learning usually occurs through direct experience or through knowledge-based inference from similar past situations. The process of decision-making involves a balance between experience-based and knowledge-based behavioral strategies. Primates, with more developed brains, are capable of inferring the outcome of a decision based on knowledge of past situations, even if they have not directly experienced those specific options before.
The orbitofrontal cortex (OFC) region of the brain in primates plays a crucial role in decision-making and helps update internal values used to assess the goodness of an option. The OFC is necessary for correctly evaluating options that individuals have no direct experience with. However, the specific roles of the OFC in decision-making and whether distinct roles rely on separate neuronal pathways have been unclear and difficult to study. A research team from Japan recently shed light on this issue by selectively turning on and off different neuronal pathways originating from the OFC in monkeys during behavioral tasks, revealing their independent functions.
The behavioral tasks involved macaque monkeys choosing between images that were associated with receiving a predetermined amount of juice as a reward. The researchers would periodically change the image sets and reverse the reward values to test the monkeys’ ability to learn through trial-and-error and knowledge-based inference. Using a chemogenetic receptor to manipulate neuronal pathways originating from the OFC, the team could determine the functions of these pathways by observing changes in the monkeys’ performance. It was found that the OFC pathway connecting to the caudate nucleus is essential for experience-based adaptation, while the pathway connecting to the mediodorsal thalamus is important for knowledge-based adaptation.
Since monkey brains share structural similarities with human brains, the findings have implications for understanding how individuals approach situations differently. Differences in thinking styles or thought patterns may be linked to how specific brain circuits are activated, which could help develop personalized strategies for improving decision-making and problem-solving skills. Additionally, understanding the roles of brain structures is important for investigating neuropathologies and psychiatric disorders. The findings could contribute to new treatments for disorders such as obsessive-compulsive disorder, where patients struggle to adapt to changing situations.
The research also has implications for artificial intelligence and robotics, where understanding brain circuits could inspire more adaptable systems that switch between different problem-solving methods depending on the situation. Studying the brain and its circuits is a crucial step towards unraveling the mysteries of how it works in both humans and other animals. By continuing to investigate brain function and decision-making processes, researchers can gain valuable insights that may lead to advancements in various fields, from psychology to neurology to artificial intelligence.