SST lateral inhibition controls the slope of psychometric contrast sensitivity. Credit: Nature Neuroscience (2025). DOI: 10.1038/s41593-025-01888-4
A multidisciplinary team of researchers at Georgia Tech has discovered how lateral inhibition helps our brains process visual information, and it could expand our knowledge of sensory perception, leading to applications in neuro-medicine and artificial intelligence.
Lateral inhibition is when certain neurons suppress the activity of their neighboring neurons. Imagine an artist drawing, darkening the lines around the contours, highlighting the boundaries between objects and space, or objects and other objects. Comparably, in the visual system, lateral inhibition sharpens the contrast between different visual stimuli.
“This research is really getting at how our visual system not only highlights important things, but also actively suppresses irrelevant information in the background,” said lead researcher Bilal Haider, associate professor in the Wallace H. Coulter Department of Biomedical Engineering. “That ability to filter out distractions is crucial.”
Understanding how these inhibitory mechanisms work could provide insights into why people have trouble filtering out distractions or focusing on what’s important in conditions like autism or ADHD.
“Our findings may also influence how we design artificial intelligence and neural networks,” said Haider, whose team published its work this month in Nature Neuroscience. “Current AI systems treat all the computing units the same, but the brain has figured out how to assign specialized computing roles.”
Joseph Del Rosario, a former graduate student in the Haider lab, was the lead author. Another key contributor was Hannah Choi, assistant professor in the School of Mathematics, and her Research Group in Mathematical Neuroscience. Their team built computational models to test the biological findings.
“Collaborating with mathematicians to really understand the computational principles underlying these inhibitory processes is a great example of how neuroscience can inform fields like AI,” Haider said.
Fine-tuning perception
The study focused on two types of inhibitory neurons in the visual cortex: parvalbumin (PV) neurons and somatostatin (SST) neurons. The researchers used optogenetics—a technique that uses light to control cell activity—to activate PV and SST neurons in the visual cortex of mice. What they observed was striking.
“What’s fascinating is that different types of inhibitory neurons seem to be doing distinct mathematical computations to achieve this suppression of the visual field,” Haider said. “It’s not a one-size-fits-all process.”
When the team activated PV neurons, visual contrast sensitivity was evenly reduced, like lowering the brightness on a computer monitor. Activation of SST neurons resulted in a more nuanced change, altering the slope of the contrast sensitivity curve, which is a graph showing how well your visual system can detect contrast.
“Basically, SST neurons fine-tune our perception of contrast more strongly by reducing extra, unnecessary signals,” Haider said. “That’s lateral inhibition at work. These inhibitory neurons play a major role in our perception. The brain has evolved this precise wiring and division of labor among different neuron types to act as the brakes in the visual system, just as important as the accelerator.”
The impact of lateral inhibition goes beyond the visual system. Similar processes may also be at work in other senses, like hearing and touch. As scientists develop a better understanding of how the brain filters sensory information, they may discover new ways to enhance or restore our overall sensory experience.
Haider first conceived the idea for this work 10 years ago when he was a postdoc. He believes the research could possibly result in new treatments for visual disorders, and lead to more flexible AI.
More information:
Joseph Del Rosario et al, Lateral inhibition in V1 controls neural and perceptual contrast sensitivity, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-01888-4
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