Hidden part of the brain controls how you prep for uncertainties

Researchers have uncovered a hidden area in the brain that controls how humans prepare for uncertainties. The claustrum, a thin sheet of neurons buried deep within the cerebral cortex, is so small and concealed that it was previously difficult for neuroscientists to investigate. In a study published in Nature Neuroscience, researchers found the first evidence of the claustrum's activity in seven patients undergoing epilepsy surgery.

The patients had electrodes implanted to identify the regions responsible for their seizures; these electrodes were equipped with 40-micrometer wires small enough to target individual neurons. Claustrum neurons wrap around the entire brain of a mouse, but human claustrum neurons are less understood. Eyiyemisi "Yemi" Damisah, the study's senior author and assistant professor of neurosurgery at Yale School of Medicine, first noticed the human claustrum while implanting an electrode on a patient's brain.

The study showed that the claustrum is the most connected region of the brain, yet it remains challenging to study. Previous animal studies, including those on reptiles, monkeys, and mice, have yielded conflicting results regarding the claustrum's role. Some studies suggest that it acts as a filter for sensory inputs, while others indicate that it regulates slow waves during sleep or influences behavioral choices.

To determine the claustrum's role in higher-order cognitive functions, Damisah's team used microwires to record the claustrum's activity during a computer game played by seven epilepsy patients. Each player controlled a spaceship, avoiding collisions with unpredictable approaching asteroids. The players learned safer paths to navigate the spaceship due to the asteroids' unpredictable movements, akin to learning how to avoid negative stimuli under uncertainty.

Damisah discovered that some claustrum neurons fired when the asteroids approached, indicating high uncertainty, while others fired when the players were unsure of their spaceship's placement, akin to high uncertainty. The claustrum's activity was more similar to the anterior cingulate cortex than the amygdala, which is involved in low-level cognitive tasks like processing emotions.

The findings suggest that the claustrum is more active during crashes than when avoidance is successful, indicating its role in tracking higher-order cognitive functions like uncertainty and prediction error. The research could lead to a better understanding of neuropsychiatric disorders related to arousal, attention, and conscious perception.