Scientists have developed a new model for understanding how different parts of the brain cooperate when visual information is ambiguous or conflicting. The findings suggest that neighboring regions of the visual cortex may continuously interact to settle on a consistent interpretation of what we see.
In a study published in Nature Neuroscience, researchers from Cold Spring Harbor Laboratory, the University of Cambridge and University College London examined two interconnected areas of the neocortex: the primary visual cortex (V1) and the lateromedial visual area (LM).
The team found that when activity in the two regions represented compatible information, the shared neural pattern persisted for longer. When the regions produced conflicting activity patterns, however, the mismatch disappeared within a fraction of a second. According to the researchers, this dynamic may represent a mechanism through which the brain builds a consensus before reaching a perceptual conclusion.
“Our goal is to understand how highly specialized brain regions can work together while still producing a consistent, unified experience,” said Mitra Javadzadeh, a Cynthia R. Stebbins Fellow at Cold Spring Harbor Laboratory.
Although different parts of the brain receive and process distinct streams of sensory information, they do not operate independently. The V1 and LM regions, for example, maintain continuous two-way communication, allowing information to flow between them.
Testing the visual circuitTo investigate how this interaction works, Javadzadeh and her colleagues trained mice to distinguish between two visual patterns tilted at different angles. The animals received a reward when they selected the correct orientation.
During the task, the researchers temporarily silenced either V1 or LM and recorded what happened to activity in the other region. They combined recordings from 194 V1 neurons and 228 LM neurons across seven mice to construct circuit models of the two brain areas.
The researchers then used an artificial neural network to model the V1-LM circuit and simulate how it responded when individual neurons were manipulated.
The simulations revealed a clear difference between conflicting and matching signals. Neural activity that represented disagreement between V1 and LM rapidly faded, while activity patterns shared by both regions persisted.
The researchers describe this process as “consensus building” — a mechanism in which interactions between brain regions progressively favor mutually consistent patterns of activity.
Could the same mechanism operate across the brain?The study focused on visual processing, but the researchers are now investigating whether a similar process occurs elsewhere in the neocortex.
One possibility is that the brain uses comparable mechanisms when information arriving through different senses does not match. For example, researchers want to determine whether similar interactions help the brain reconcile what a person sees with what they hear.
If the mechanism proves to be widespread, it could provide new insights into how the brain integrates information across specialized regions and what happens when those regions fail to arrive at a consistent interpretation.
The findings may also offer ideas for artificial intelligence, where systems must often combine information that is incomplete or contradictory.
“While we understand individual building blocks of the brain, what is the glue that puts them together?” Javadzadeh said. “Knowing that can finally help us understand how the brain works as a whole.”
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