Georgia State researcher receives $1.93 million NIH award to study visual processing

Jordan Hamm, an assistant professor of neuroscience at Georgia State University, has received a five-year, $1.93 million award from the National Eye Institute at the National Institutes of Health (NIH).

Hamm and his co-investigator, Darcy Peterka of Columbia University, will examine how the brain processes and responds to visual information. Their findings could provide insight into diagnosing and treating psychiatric disorders.

The project aims to better understand how the brain builds predictions about visual information it thinks it's going to see and, notably, how it detects when stimuli in the visual field deviate from its expectation."

Jordan Hamm, Assistant Professor of Neuroscience, Georgia State University

The brain's use of context and previous sensory experiences to predict future sensory input is known as predictive processing. Information the brain anticipates is processed quickly, allowing the brain to focus on more important material. Sometimes, however, the brain's experience is not as predicted.

"The things that deviate from our expectations, they're important for learning," Hamm said. "If we enter a room that we've been in a thousand times and suddenly there's a new chair in the corner, it will evoke a large response in the sensory processing parts of our brain. This enhanced response is what helps us update what we know about that room and how we behave."

When the brain recognizes that its prediction differs from reality, a process known as deviance detection, it uses the new information to adjust its previous understanding. Predictive processing helps the brain make sense of the world.

However, some neurological and psychiatric disorders are characterized by deficits in these functions. Failure to detect deviance results in a brain that forms beliefs about the world despite contradictory sensory experience, or a brain that creates its own sensory experience.

"The same altered brain systems that give rise to reduced predictive processing may also give rise to aberrant sensory experience," Hamm said.

Using mice as a model, Hamm and Peterka aim to identify the neurons within this brain system that generate deviance detection. They will show the mice a repeating sequence of visual stimuli and monitor the specific neurons that activate when a stimulus that deviates from the pattern is shown. In doing so, they will map the neuronal circuitry of deviance detection.

"If we can understand which neurons are critical for this function of the brain, we may come away with new angles to diagnose and treat psychiatric disorders," Hamm said.

This is Hamm's second NIH Research Project grant (R01), a highly competitive award that funds projects with strong preliminary data and potential to improve public health.