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	<title>systems neuroscience &#8211; Science</title>
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	<title>systems neuroscience &#8211; Science</title>
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		<title>How the Brain&#8217;s Cortex Reaches Agreement: Reciprocal Circuits Build Consensus Across Areas</title>
		<link>https://scienmag.com/how-the-brains-cortex-reaches-agreement-reciprocal-circuits-build-consensus-across-areas/</link>
		
		<dc:creator><![CDATA[Cassandra Pierce]]></dc:creator>
		<pubDate>Tue, 22 Sep 2026 18:01:58 +0000</pubDate>
				<category><![CDATA[Medicine]]></category>
		<category><![CDATA[connections]]></category>
		<category><![CDATA[consensus building in the brain]]></category>
		<category><![CDATA[consensus dynamics]]></category>
		<category><![CDATA[consensus formation in neuroscience]]></category>
		<category><![CDATA[cortical area communication]]></category>
		<category><![CDATA[cortical area integration]]></category>
		<category><![CDATA[cortical connectivity and function]]></category>
		<category><![CDATA[cortical hierarchy]]></category>
		<category><![CDATA[distributed neural processing]]></category>
		<category><![CDATA[dynamic neural exchange]]></category>
		<category><![CDATA[feedforward and feedback]]></category>
		<category><![CDATA[functional connectivity]]></category>
		<category><![CDATA[hierarchical versus reciprocal cortical models]]></category>
		<category><![CDATA[multi-area neural coordination]]></category>
		<category><![CDATA[Nature Neuroscience]]></category>
		<category><![CDATA[neocortex]]></category>
		<category><![CDATA[Neocortical reciprocal circuits]]></category>
		<category><![CDATA[neural circuits]]></category>
		<category><![CDATA[neural feedback and feedforward pathways]]></category>
		<category><![CDATA[neuroscience of perception and decision-making]]></category>
		<category><![CDATA[perceptual decision-making]]></category>
		<category><![CDATA[Reciprocal]]></category>
		<category><![CDATA[reciprocal connections]]></category>
		<category><![CDATA[systems neuroscience]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=207455</guid>

					<description><![CDATA[New research in Nature Neuroscience shows that reciprocal connections between neocortical areas dynamically reweight their communication to build consensus across the cortex, shaping perception and decision-making.]]></description>
										<content:encoded><![CDATA[<p>Every time you recognize a face, reach for a coffee cup, or decide that the shape in your peripheral vision is a friend rather than a shadow, dozens of specialized regions across your neocortex must agree on what is happening. Each cortical area contributes a different slice of the picture — one extracts edges and motion, another links that motion to memory, a third converts the whole into an action plan. How these areas, each with its own timing, cellular composition and processing logic, settle on a single coherent interpretation has long been one of neuroscience&#8217;s central puzzles. A new study published in Nature Neuroscience offers a striking answer: cortical areas do not simply pass messages down a one-way hierarchy. Instead, they are bound together by reciprocal connections whose ongoing, dynamic exchange allows distributed populations of neurons to negotiate and converge on shared conclusions, effectively building consensus across the cortical sheet.</p>
<p>The research team set out to test whether the dense web of feedforward and feedback projections linking neocortical areas functions as more than a pipeline for transmitting already-computed results. Prior work had established the anatomical scaffolding — every pair of connected cortical areas exchanges projections in both directions, and feedback fibers often numerically dominate their feedforward counterparts. But functional studies frequently treated these reciprocal loops as static wiring diagrams, as if the connections were fixed channels whose influence never changed. The new experiments challenged that assumption directly, asking whether the strength and direction of communication between areas shifts on fast timescales depending on what the network is doing and what the animal is perceiving.</p>
<p>To address the question, the researchers combined high-density electrophysiology with targeted circuit manipulations in animal models, recording simultaneously from multiple neocortical areas while subjects performed perceptual tasks. Rather than analyzing activity in each area in isolation, the team focused on the interaction terms — the moment-by-moment statistical relationships between spiking patterns in different regions. These relationships revealed a constantly reconfiguring dialogue. During the earliest phase of stimulus processing, feedforward signals dominated, consistent with the classical view of information flowing up a sensory hierarchy. But within hundreds of milliseconds, as the network settled on an interpretation, feedback and lateral influences grew dramatically, and activity across areas began to align toward a shared pattern — the neural signature of consensus formation.</p>
<p>The technical heart of the study lies in how the authors quantified this alignment. Using multielectrode arrays positioned across connected cortical fields, they tracked dimensionality-reduced activity trajectories in each area and measured how those trajectories converged or diverged over time. Their analyses showed that consensus was not achieved by one area imposing its answer on another. Instead, the reciprocal projections acted like a bidirectional negotiation channel: each area&#8217;s output pushed its partners toward its own state, while simultaneously being pulled toward the states of those partners. When the team modeled this interaction mathematically, the dynamics resembled consensus algorithms used in distributed computing and swarm robotics, in which individual agents repeatedly exchange estimates and update their own state as a weighted average of their neighbors&#8217; — a process that provably converges on collective agreement.</p>
<p>What makes the biological version remarkable is that the weights of that averaging are not fixed. Perturbation experiments demonstrated that the influence one area exerts on another depends on the internal state of both regions at the moment of communication. When a downstream area was highly engaged — for example, during periods of heightened attention or just before a behavioral choice — its feedback projections reshaped upstream activity far more powerfully than during passive viewing. Conversely, when the researchers transiently silenced one node of the reciprocal loop, the consensus process did not collapse; the remaining areas re-balanced their exchanges, partially compensating for the lost input. This redundancy reveals a network that is robust by design, with agreement emerging from the architecture of mutual influence rather than from any single commanding region.</p>
<p>The findings carry major implications for how neuroscientists understand cortical hierarchy. For decades, the dominant framework organized neocortical areas into a ladder: primary sensory cortex at the bottom, association cortex in the middle, and prefrontal regions issuing commands at the top. The new evidence suggests that hierarchy is only half the story. Even areas separated by many synaptic steps behave less like superiors and subordinates and more like participants in an ongoing committee meeting, each contributing evidence and revising its own verdict in light of what its partners report. Consensus, on this view, is not decreed at the top of the hierarchy — it is computed continuously across the entire network, and behavior reflects the outcome of that distributed vote.</p>
<p>The timing of the consensus process also aligns closely with behavior. The researchers found that the moment when activity across cortical areas converged onto a shared trajectory predicted, on a trial-by-trial basis, the moment the animal committed to a perceptual decision. Trials in which the reciprocal dialogue resolved quickly produced fast, confident choices; trials marked by prolonged disagreement — visible as sustained divergence between regional activity patterns — produced slower responses and greater variability. This tight coupling between inter-areal negotiation and decision time suggests that the subjective experience of certainty may correspond, at the circuit level, to the successful resolution of the cortical consensus process itself.</p>
<p>Beyond perception, the work offers a fresh lens on disorders in which cortical communication is thought to go awry. Conditions such as schizophrenia and autism have long been associated with altered functional connectivity between brain regions, and theories of psychosis propose that perception breaks down when distant cortical areas stop agreeing on a shared model of reality. The new framework makes such ideas concrete: if consensus is an active, dynamically weighted computation carried out by reciprocal projections, then genetic or developmental disruptions that alter those projections could shift how easily cortical networks converge, producing both the sensory anomalies and the decision-making irregularities observed clinically. Similarly, age-related declines in white matter integrity could degrade the bandwidth of the negotiation channel, explaining why perceptual decisions become slower and more variable with advancing age.</p>
<p>The study also points toward new therapeutic and technological directions. Brain–computer interfaces, which decode intentions from cortical activity, currently rely heavily on signals from small numbers of areas; a consensus-based framework suggests that reading out the converged state of a reciprocal network, rather than any single region&#8217;s output, could yield more stable and accurate decoders. On the basic science side, the results generate testable predictions about the synaptic and neuromodulatory mechanisms that control the dynamic weights of inter-areal communication — questions the authors and their colleagues are already pursuing. In the meantime, the study reframes a familiar picture of the brain. The neocortex, with its patchwork of specialized areas, now appears less like an assembly line and more like a parliament: a legislature of parallel experts whose reciprocal connections, updated moment by moment, allow the mind to speak with one voice.</p>
<p><strong>Subject of Research:</strong> Dynamic reciprocal connectivity and consensus formation between neocortical areas during perception and decision-making</p>
<p><strong>Article Title:</strong> Reciprocal connections dynamically build consensus between neocortical areas</p>
<p><strong>Article References:</strong> Javadzadeh, M., Schimel, M., Hofer, S. B., Ahmadian, Y., &amp; Hennequin, G. (2026). Reciprocal connections dynamically build consensus between neocortical areas. <em>Nature Neuroscience</em>. <a href="https://doi.org/10.1038/s41593-026-02437-3" rel="noopener noreferrer">https://doi.org/10.1038/s41593-026-02437-3</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1038/s41593-026-02437-3" rel="noopener noreferrer">10.1038/s41593-026-02437-3</a></p>
<p><strong>Keywords:</strong> neocortex, reciprocal connections, cortical hierarchy, consensus dynamics, feedforward and feedback, perceptual decision-making, neural circuits, functional connectivity, Nature Neuroscience, systems neuroscience, Reciprocal, connections</p>
]]></content:encoded>
					
		
		
		<post-id xmlns="com-wordpress:feed-additions:1">207455</post-id>	</item>
		<item>
		<title>Silent fMRI Framework Captures Brain-Wide Networks in Behaving Mice</title>
		<link>https://scienmag.com/silent-fmri-framework-captures-brain-wide-networks-in-behaving-mice/</link>
		
		<dc:creator><![CDATA[Colin Clarke]]></dc:creator>
		<pubDate>Fri, 11 Sep 2026 23:50:47 +0000</pubDate>
				<category><![CDATA[Medicine]]></category>
		<category><![CDATA[awake behaving mice]]></category>
		<category><![CDATA[brain network mapping in small animals]]></category>
		<category><![CDATA[brain networks]]></category>
		<category><![CDATA[brain-wide networks in behaving mice]]></category>
		<category><![CDATA[compatibility with cellular and chemical validation]]></category>
		<category><![CDATA[complex behavior brain dynamics]]></category>
		<category><![CDATA[functional magnetic resonance imaging in rodents]]></category>
		<category><![CDATA[functional MRI]]></category>
		<category><![CDATA[MacKinnon]]></category>
		<category><![CDATA[motion-resistant fMRI techniques]]></category>
		<category><![CDATA[Nature Neuroscience]]></category>
		<category><![CDATA[neuroimaging]]></category>
		<category><![CDATA[neuroimaging during active behaviors]]></category>
		<category><![CDATA[neuroimaging in laboratory mammals]]></category>
		<category><![CDATA[Noam Shemesh]]></category>
		<category><![CDATA[overcoming MRI noise challenges in mice]]></category>
		<category><![CDATA[preclinical imaging]]></category>
		<category><![CDATA[rodent brain imaging]]></category>
		<category><![CDATA[silent fMRI]]></category>
		<category><![CDATA[silent neuroimaging technology]]></category>
		<category><![CDATA[SORDINO-fMRI]]></category>
		<category><![CDATA[systems neuroscience]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=193150</guid>

					<description><![CDATA[A new silent, motion-resistant fMRI framework called SORDINO enables artifact-free, brain-wide imaging of awake, behaving mice while supporting simultaneous cellular and chemical validation.]]></description>
										<content:encoded><![CDATA[<p>For decades, functional magnetic resonance imaging has offered scientists an unmatched window into the human brain, revealing whole-brain networks at work without a single incision. Yet when researchers attempt to bring that same power to bear on the smallest and most behaviorally sophisticated laboratory mammals, they run into a wall of physics and physiology. A new framework described by MacKinnon and colleagues, and highlighted in a News &amp; Views piece by Noam Shemesh in Nature Neuroscience, promises to tear down that wall. Called SORDINO-fMRI, the approach captures global brain dynamics in mice during complex behaviors while remaining silent, motion-resistant, and compatible with simultaneous cellular or chemical validation techniques. It is, as the commentary&#8217;s title suggests, a silent leap in neuroimaging.</p>
<p>To appreciate why this matters, one must first understand the stubborn technical difficulties that have long constrained rodent fMRI. Mapping brain-wide networks in behaving animals remains a formidable challenge for reasons rooted in the basic mechanics of magnetic resonance. Conventional fMRI relies on echo-planar imaging sequences that generate loud acoustic noise, often exceeding one hundred decibels inside the scanner bore. For a human volunteer lying still with ear protection, that noise is an annoyance. For a mouse, an animal whose hearing is far more sensitive and whose experimental value depends on natural behavior, the acoustic barrage is a confound of the first order. It activates auditory circuits, triggers stress responses, alters arousal, and contaminates precisely those network signals researchers hope to measure.</p>
<p>The problem compounds when the goal is to image animals that are awake and moving. Standard echo-planar sequences are exquisitely sensitive to motion, and even the small head movements of a behaving mouse produce artifacts that can dwarf the subtle blood-oxygenation-level-dependent signals of interest. Traditional workarounds, such as anesthetizing animals or restraining their heads while training them to tolerate the scanner, solve one problem by creating another. Anesthesia suppresses consciousness and reorganizes neural dynamics, so the networks measured under it are not the networks of a behaving animal. Head fixation permits imaging during limited tasks but rules out the rich, ethologically meaningful behaviors, navigation, social interaction, foraging, that make rodents so valuable as models in the first place.</p>
<p>SORDINO-fMRI addresses both obstacles at once. The framework is silent, eliminating the acoustic confound that plagues conventional sequences, and it is motion-resistant by design, so that the global dynamics of freely orchestrating animals can be captured without the ghosting, blurring, and signal dropout that normally accompany movement in the magnet. According to the News &amp; Views summary, the method captures global dynamics during complex behaviors in mice while enabling artifact-free simultaneous network-level recordings with cellular or chemical validation. That last clause deserves emphasis: SORDINO-fMRI does not operate in isolation but can be paired, in the same scanning session, with techniques that read out neural activity or neurochemistry at the cellular scale. This creates a rare multimodal platform in which whole-brain network dynamics and mechanistic ground truth can be acquired in parallel.</p>
<p>The significance of this convergence becomes clear when one considers how neuroscience has been pulled in two directions by its tools. On one side, techniques such as widefield calcium imaging, two-photon microscopy, and high-density electrophysiology offer cellular or near-cellular resolution, but each covers only a limited field of view. Landmark large-scale efforts, including work from the International Brain Laboratory and the population recordings of Stringer and colleagues as well as Steinmetz, Zatka-Haas, Carandini, and Harris, have shown how much can be learned from recording many neurons or many brain regions simultaneously. Yet even hundreds of targeted probes cannot deliver a truly brain-wide picture in a small rodent brain without gaps. On the other side, fMRI delivers that brain-wide coverage but has historically lacked cellular specificity and, in rodents, behavioral realism. SORDINO-fMRI aims to close this gap, bringing whole-brain functional imaging into the awake, behaving regime where modern systems neuroscience now lives.</p>
<p>The timing of this advance is not accidental. The past several years have seen an intensifying effort to legitimize and improve rodent fMRI as a translational bridge between human imaging and circuit neuroscience. Reviews and methodological papers by Gao and colleagues, by Mandino, Vujic, Grandjean, and Lake, and by Daley, Pan, Kaundinya, and Keilholz have catalogued both the promise and the pitfalls of preclinical fMRI, from anesthesia confounds to the challenge of interpreting blood-oxygenation signals in a brain the size of a hazelnut. Studies by Yu and colleagues, and by Bolt and colleagues, have pushed toward whole-brain imaging of neural dynamics, while Rauscher and colleagues and Pagani and colleagues have recently expanded the frontier of what functional imaging in rodents can reveal. Lake and colleagues established foundations for imaging neural activity in awake animals that have informed the field&#8217;s trajectory. Shemesh&#8217;s commentary situates SORDINO-fMRI squarely within this arc, arguing that it opens new opportunities in preclinical imaging and systems neuroscience.</p>
<p>What might those opportunities look like in practice? Consider a mouse navigating a virtual or physical maze while its brain is imaged silently. Because the animal is awake and behaving, the researchers can ask how distributed networks, hippocampal, cortical, subcortical, coordinate in real time as the animal makes decisions, encodes space, or responds to rewards. Because the readout is artifact-free, fluctuations in the blood-oxygenation signal can be attributed to neural dynamics rather than to head motion or acoustic startle. And because simultaneous cellular or chemical validation is possible, the researchers can anchor the macroscopic network measurements to known quantities: the firing of specific neuronal populations, or the release of specific neuromodulators. This triangulation across scales is precisely what the field has needed to translate insights about circuit mechanisms into models that can be tested against human brain imaging, and vice versa.</p>
<p>The preclinical implications extend into translational medicine. Rodent models are indispensable for studying neurological and psychiatric disease, from Parkinson&#8217;s and epilepsy to depression and schizophrenia, but the field has long struggled with the failure of therapies that succeed in mice and fail in humans. A significant part of that failure is measurement: preclinical readouts often do not correspond to the outcome measures used in clinical trials. A method that can image brain-wide network function in behaving disease-model mice, with the same modality, fMRI, that is used in patients, offers a more direct translational axis. Network-level phenotypes measured with SORDINO-fMRI could, in principle, be compared quantitatively with resting-state and task-based networks in human patients, enabling a more rigorous back-and-forth between bench and bedside.</p>
<p>None of this diminishes the substantial work that remains. Interpreting fMRI signals in rodents requires careful attention to neurovascular coupling, which may differ across species, brain regions, and behavioral states. Combining fMRI with optogenetics, electrophysiology, or pharmacology in the same session demands exquisite engineering, from radiofrequency-compatible hardware to protocols that keep animals healthy and cooperative inside a magnet. Shemesh, who directs research at the Weizmann Institute of Science and the Champalimaud Foundation and who has long championed advanced diffusion and functional MRI methods, is well placed to evaluate these challenges, and his commentary treats SORDINO-fMRI as a genuine advance rather than a finished solution. He discloses service on the scientific advisory board of Bruker Biospin, a reminder that the industrial ecosystem around preclinical imaging is actively engaged with these developments.</p>
<p>Still, the phrase that will linger with readers is the one Shemesh chose for his title: a silent leap. The word silent is literal, a reference to the acoustically quiet acquisition that makes natural behavior possible inside the scanner. But it also captures the way this methodological shift arrives without fanfare amid the louder headlines of AI models and brain-computer interfaces, quietly removing constraints that have shaped decades of experimental design. If SORDINO-fMRI performs as described, the neuroscience community gains something it has never had before: a way to watch entire mammalian brains orchestrate real behavior, at network scale, validated at the cellular level, all in a single experiment. For preclinical imaging and systems neuroscience alike, that is not an incremental improvement. It is a change in what questions can be asked at all, and the answers to those questions may reshape how we understand the brain in motion, in health, and in disease.</p>
<p>One useful way to situate the advance is through the physics of the blood-oxygenation-level-dependent signal itself. Because the hemodynamic response that fMRI measures unfolds over roughly a second or more, it is inherently slower than the millisecond-timescale spiking that electrophysiology captures, and its amplitude depends on local neurovascular mechanisms rather than on neural activity alone. This is why pairing network-level imaging with cellular or chemical readouts in the same session is so valuable: it allows investigators to calibrate what the vascular signal actually reflects under a given behavioral state, rather than assuming that coupling parameters measured in anesthetized preparations carry over unchanged.</p>
<p>The multimodal design also speaks to a broader trend in systems neuroscience toward convergent evidence. When a macroscopic network fluctuation can be checked against, for example, the concurrent firing of a defined neuronal population or the release of a neuromodulator, interpretations move from plausible to testable. Such cross-scale validation has historically required separate experiments in separate animals, introducing variability that complicates comparison. Acquiring the modalities simultaneously in the same animal ties them together temporally, so that a transient change in global dynamics can be linked to its cellular substrate at the very moment it occurs. For preclinical studies of disease models, where network alterations may be subtle and state-dependent, that temporal alignment could prove as consequential as the silence and motion resistance themselves.</p>
<p><strong>Subject of Research:</strong> A silent, motion-resistant fMRI framework for brain-wide imaging of behaving mice</p>
<p><strong>Article Title:</strong> A silent leap in neuroimaging</p>
<p><strong>Article References:</strong> Shemesh, N. (2026). A silent leap in neuroimaging. <em>Nature Neuroscience</em>. <a href="https://doi.org/10.1038/s41593-026-02401-1" rel="noopener noreferrer">https://doi.org/10.1038/s41593-026-02401-1</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1038/s41593-026-02401-1" rel="noopener noreferrer">10.1038/s41593-026-02401-1</a></p>
<p><strong>Keywords:</strong> SORDINO-fMRI, functional MRI, neuroimaging, rodent brain imaging, awake behaving mice, brain networks, systems neuroscience, preclinical imaging, Nature Neuroscience, Noam Shemesh, MacKinnon, silent fMRI</p>
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