Summary: Researchers have discovered how sensory information is processed across the body’s intricate and versatile sites.
The idea of a plain, straight flow of visual input is challenged by one study, which found that visual signals are selectively targeted or loosely broadcast. A subsequent study demonstrated that the thalamus adjusts sensory processing to behavioural patterns, placing back-to-front motion as a priority during arousal.
Together, these findings reveal active mechanisms that influence understanding and provide ways to influence brain functionality for upcoming interventions.
Important Facts:
- Broadcast vs. Targeted Signals: Physical pathways either broadcast broad amounts of brain activity to integrate brain activity.
- Thalamus Modulation: Visual running in the brain changes with intimacy, prioritizing specific movements during heightened states.
- Dynamic Visual Network: The head adapts sensory processing based on cognitive environment, never through a fixed, step-by-step method.
Origin: VIB
Two new studies have been published by researchers at Neuro-Electronics Research Flanders ( NERF), under the direction of Prof. Vincent Bonin, that examine how visual information is processed and distributed in the brain.  ,
The studies show how complicated and flexible sensory information running in the mind is.
The visible cortex, a critical area for running and interpreting visual input, has a significant impact on shaping what we see. The neural circuits that process visual information are being studied by Vincent Bonin, a professor at KU Leuven and a team leader at NERF.
” We frequently think of visual processing in the brain as a simple, linear approach,” explains Prof. Bonin, but our research shows that it operates as a complex system with carefully tuned links between areas, supporting specialized visual functions across different mind areas.
Targeting over broadcasting
In a second research published in , Current Biology,  , postdoctoral scholar Xu Han , revealed how sensory information is transmitted across different connected areas in the mind.
Han and Bonin identified pathways that neither carefully channel visible signals to qualified areas or broadcast information loosely across several regions by using advanced imaging and circuit-tracing techniques in mice.  ,  ,
” For instance, neurons in the pulvinar and certain layers of the cortex are finely tuned to their targets, suggesting a role in constructing detailed visual representations”, explains Han.
” In contrast, deeper neurons seem to ignore target specificity, broadcasting similar visual information across areas—possibly for coordinating broader brain activity” . ,  ,
These findings challenge the long-held belief that visual information flows in a simple, step-by-step manner, instead revealing a highly dynamic and adaptable network.
Quiet vs aroused
In the second study, published in , Cell Reports, Bonin and Dr. Karolina Socha ( now at the University of California in LA ) explored how the brain’s thalamus—a key relay station for visual signals—adjusts information processing depending on behavioral states.  ,
The researchers found that during quiet wakefulness, neurons in the thalamus amplify signals for back-to-front motion, a transformation absent under anesthesia or heightened arousal.
They discovered that this modulation is related to changes in the pupil size, a sign of arousal, by studying the activity of neurons in awake mice.  ,
According to Bonin, “larger pupils coincided with stronger responses to back-to-front motion,” suggesting that the thalamus combines sensory inputs with behavioral context to prioritize particular visual stimuli.
” These findings demonstrate how the thalamus integrates behavioral context to dynamically shape visual representations, altering how motion is processed and prioritized” . ,
Predict and manipulate perception
Together, both studies represent a major step toward creating a detailed “functional-anatomical map” of the brain’s visual system.
Understanding these mechanisms and pathways makes it possible to control how perception operates, says Bonin.
These findings advance neuroscience research and offer the potential for the creation of targeted brain function-modulation interventions.
Funding
The research (team ) was supported by VIB, KU Leuven, imec, the Research Foundation Flanders ( FWO ), and KU Leuven Research Council.
About this news from a study on visual neuroscience
Author: India Jane Wise
Source: VIB
Contact: India Jane Wise – VIB
Image: The image is credited to Neuroscience News
Original Research: Open access.
Vincent Bonin and colleagues ‘” In the mouse cortex, higher-order cortical and thalamic pathways modulate visual processing pathways..” Current Biology
Open access.
Vincent Bonin and colleagues ‘ study,” Neuronal visual tuning in the mouse thalamocortical pathway can be altered by behavioral modulations..” Cell Reports
Abstract
In the mouse cortex, higher-order cortical and thalamic pathways modulate visual processing pathways.
Mammalian visual processing relies on distributed processing across interconnected cortical and subcortical regions.
Visual features are processed in higher-order visual areas ( HVAs ) using specialized streams that incorporate feedforward and higher-order inputs from intracortical and thalamocortical pathways.
The precise circuit organization tasked with HVA specialization is still a mystery.
We investigated the cellular architecture of primary visual cortex ( V1 ) and higher-order visual pathways in the mouse, focusing on their roles in shaping visual representations.
Using , in , vivo , functional imaging and neural circuit tracing, we found that HVAs preferentially receive inputs from both V1 and higher-order pathways tuned to similar spatiotemporal properties, with the strongest selectivity seen in layer 2/3 neurons.
These neurons exhibit target-specific tuning and sublaminar specificity in their projections, reflecting cell-type-specific visual information flow.
In contrast, HVA layer 5 pathways non-specifically transmit visual signals across cortical regions, suggesting a role in the distribution of HVA outputs.
Additionally, thalamocortical pathways from the lateral posterior thalamic nucleus ( LP ) provide highly specific, nearly non-overlapping visual inputs to HVAs, complementing intracortical inputs and contributing to input functional diversity.
Our findings indicate that the functional specialization and diversity of HVAs is influenced by the convergence of laminar and cell-type-specific pathways V1 and higher-order intracortical and thalamocortical pathways.
Abstract
Neuronal visual tuning in the mouse thalamocortical pathway can be altered by behavioral modulations.
Although their precise effects on visual tuning are undetermined, behavioral influences shape processing in the dorsal lateral geniculate nucleus and the dorsal lateral geniculate nucleus (dLGN ) are.
Using 2-photon functional Ca2+ , imaging, we characterize the dynamics of dLGN axon activity in the primary visual cortex of awake behaving mice, examining the effects of visual stimulation, pupil size, stillness, locomotion, and anesthesia.
In awake recordings, nasal visual motion triggers pupil dilation and, occasionally, locomotion, increasing responsiveness and leading to an overrepresentation of boutons tuned to nasal motion.
These effects are pronounced during quiet wakefulness, weaker during locomotion, and absent under anesthesia.
Tuning biases are reduced by taking into account dynamic changes in responsiveness, which reveals that retinal representations of visual motion in the visual thalamocortical pathway are still maintained overall.
Thus, early visual neurons may be affected by stimulus-driven behavioral modulations, which highlights the importance of taking into account such influences in sensory processing experiments.
