The ability to adapt one's beliefs about actions and their consequences in a constantly changing environment is a hallmark of advanced cognition. Disruptions to this ability can negatively impact cognition and behavior, potentially leading to states of mind such as paranoia, where there is a belief that others intend to cause harm.
In a groundbreaking study, Yale scientists have identified a specific brain region that might causally provoke feelings of paranoia. This study, published in the journal Cell Reports, presents a novel cross-species framework that aligns data collected from monkeys with human data, providing new insights into human cognition through the study of other species.
Previous research has implicated certain brain regions in paranoia, but understanding of its neural underpinnings has remained limited. The Yale researchers analyzed existing data from multiple previous studies involving both humans and monkeys. In these studies, participants performed a task designed to measure how volatile they perceived their environment to be. The task involved selecting one of three options on a screen, each associated with different probabilities of receiving a reward.
Participants had to discover the best option by trial and error, with the reward probabilities periodically switching without warning. This setup required participants to adapt their behavior based on their perceived environmental changes. The researchers used this task to gather data on how adaptive behavior is and how volatile participants view their environment.
Steve Chang, associate professor of psychology and neuroscience at Yale, explains, “Participants have to figure out the best target, and when there's a perceived change in the environment, they must identify the new best target.” This process involves analyzing clicking behavior before and after the probability switch to infer environmental volatility perceptions and adaptability.
Philip Corlett, associate professor of psychiatry at Yale, adds, “We used the same computational analysis on both human and monkey data. The computational model, a series of equations explaining behavior, serves as a common language between the two datasets, allowing for direct comparison.”
In previous studies, some monkeys had specific lesions in either the orbitofrontal cortex, associated with reward-related decision-making, or the mediodorsal thalamus, which sends environmental information to decision-making centers in the brain. Among human participants, some reported high levels of paranoia while others did not.
This study's innovative approach offers a promising method for understanding the neural basis of paranoia and other cognitive states by leveraging comparative data from both humans and animals. The findings could pave the way for future research into the neural mechanisms underlying adaptive behavior and mental health conditions.
Source: Yale University