Brain Regions Linked to Paranoia Revealed

Yale scientists have uncovered how a specific brain region might provoke feelings of paranoia, using a novel cross-species research approach. The study analyzed data from both monkeys and humans performing a task that measured their perception of environmental volatility and adaptability.

Participants in the studies had to choose between three options on a screen, each associated with different probabilities of receiving a reward. They had to identify the best option through trial and error, and adapt when the reward probabilities changed unexpectedly. The participants’ behaviors before and after these changes revealed their perceptions of environmental stability and their adaptive capabilities.

The researchers applied the same computational analysis to both datasets, using a model to explain behavior and compare results between species. This approach helped them identify how the brain regions of interest—the orbitofrontal cortex (OFC) and the mediodorsal thalamus (MDT)—affected behavior.

Monkeys with lesions in the OFC tended to stick with the same options even when not rewarded, while those with lesions in the MDT displayed erratic switching behavior, similar to humans with high paranoia. This suggested that the MDT plays a significant role in how people perceive environmental volatility and experience paranoia.

The findings provide insight into the neural underpinnings of paranoia and offer a pathway for studying complex human behaviors in simpler animals. This research could also help assess how pharmaceutical treatments for paranoia affect the brain and potentially lead to new treatments for reducing paranoia in humans. The study was led by co-first authors Praveen Suthaharan, a graduate student in Corlett’s lab, and Summer Thompson, an associate research scientist in Yale’s Department of Psychiatry, in collaboration with Jane Taylor, the Charles B.G. Murphy Professor of Psychiatry at Yale School of Medicine. The work was published in the journal Cell Reports on June 13.

Story Source: Yale University [Link]. Originally written by Mallory Locklear. Edited for style and length.