The core insight is that three large bodies of research have grown up largely in isolation. One line of work shows that people with chronic low back pain often perceive their back differently, reporting a diminished sense of connection to it or uncertainty about its size and position. A second documents changes in the motor cortex’s control of trunk muscles, including shifted and enlarged cortical maps of the deep abdominal muscle transversus abdominis in people with recurrent pain. A third reveals altered pain processing, from heightened sensitivity to pressure at sites far from the back to less efficient endogenous pain modulation. What has never been done, the author notes, is measuring all three domains concurrently in the same well-characterized cohort, leaving open whether they covary, which comes first, and whether any of them explains the others.

To organize these threads, the framework borrows from predictive coding, a computational theory of the brain formalized by Karl Friston. Under this view, the brain constantly predicts incoming sensory signals and updates its internal models when prediction errors accumulate. Movement, in the related active-inference account, is not commanded top-down but emerges as the body fulfills proprioceptive predictions. Applied to back pain, the hypothesis is that persistent nociceptive input or altered sensorimotor processing could disrupt the updating of predictions about trunk state, allowing mismatches between predicted and actual bodily signals to persist. That persistent mismatch could then couple distorted trunk-state estimation to changes in motor regulation, bodily perception, and pain processing in a mutually reinforcing loop.

The focal candidate mechanism is the body schema, the action-oriented, largely unconscious representation that supports movement planning and online control. Crucially, the author is careful about measurement. No existing instrument directly measures the body schema; researchers rely on proxies such as the left/right judgment task, which is interpreted as indexing implicit motor imagery; the lumbar two-point discrimination threshold, a behavioral index of tactile-spatial acuity; and the Fremantle Back Awareness Questionnaire, a self-report measure of conscious back-perception disturbance. Each captures a different phenomenon, and their reliability, measurement error, and construct structure in low back pain remain incompletely established.

The empirical evidence is suggestive but uneven. Studies have found higher lumbar two-point discrimination thresholds in people with chronic low back pain, sometimes linked to greater gray-matter volume in the back region of primary somatosensory cortex and altered S1-thalamic connectivity. Elevated thresholds appear most clearly in subgroups with predominant central-sensitization features, hinting that these disturbances may characterize only part of the population. Laterality-judgment findings are heterogeneous, with some studies showing slower or less accurate trunk judgments and others finding preserved performance with altered brain responses. Self-reported back-perception disturbance, meanwhile, is consistently higher in patients and correlates with pain, disability, catastrophizing, and psychological distress.

On the motor side, transcranial magnetic stimulation studies reveal a complex picture. Some abnormalities appear in remote muscles such as the hand, suggesting a generalized change in motor-system state rather than a trunk-specific one. Trunk-muscle mapping studies have shown shifted cortical representations of transversus abdominis associated with delayed anticipatory muscle activation, and reduced map volume with loss of spatial separation between deep back muscles. A recent systematic review and meta-analysis of thirty-three studies found low to moderate certainty evidence for lower paraspinal corticospinal excitability, but concluded that findings must be interpreted separately by target muscle and outcome rather than collapsed into a single corticomotor abnormality.

Pain processing forms the third domain, operationalized through pressure pain thresholds, temporal summation of pain, and conditioned pain modulation. Meta-analytic evidence indicates less efficient conditioned pain modulation in chronic low back pain, while facilitated temporal summation appears in both acute and chronic presentations. The framework insists these psychophysical measures be kept distinct from related but non-interchangeable concepts such as nociplastic pain criteria, central sensitization, and Central Sensitization Inventory symptom burden. Notably, a recent multivariate imaging study found preserved mechanoreceptive somatotopy in the somatosensory and motor cortices of patients despite their greater self-reported back-perception disturbance, arguing against simple cortical map degradation as a necessary explanation and sharpening the question of what, exactly, is altered.

Because the directional architecture remains untested, the framework lays out four competing models: a body-representation-led account in which miscalibrated trunk-state estimation organizes the other domains; a pain-processing-led account in which altered pain sensitivity drives perceptual and motor changes; a motor-system-led account in which altered movement changes the sensory evidence available for updating body models; and a shared-upstream account in which threat learning, attention, affective state, or systemic influences generate parallel variation without direct causation among the domains. Fear and avoidance could occupy different positions in each, acting as upstream drivers, mediators, or consequences. Once reciprocal feedback develops, different initiating architectures may produce increasingly similar cross-sectional patterns, which is why the author treats mutual reinforcement as a maintenance process rather than a fifth initiating model.

To make the framework falsifiable, the paper specifies a construct-validity prerequisite and four predictions. First, body-representation measures should add reproducible explanatory information about corticomotor and pain-processing outcomes beyond pain intensity, disability, psychological variables, and nociplastic features. Second, those cross-domain associations should be stronger when independently assessed nociplastic features converge. Third, interventions designed to recalibrate trunk-state estimation should produce change in a valid target indicator that then predicts or mediates change in motor regulation and pain processing, beyond expectancy and general treatment effects. Fourth, longitudinal cohorts should test whether early change in body-representation measures predicts later motor or pain outcomes, comparing all four architectures in formal model comparison.

The clinical stakes are considerable. If a valid indicator of trunk-state estimation could be selectively changed and that change shown to precede improvements in motor control and pain, it would offer a precisely specified sensorimotor entry point for rehabilitation, distinguishable from placebo, belief change, or task practice. Existing evidence offers only partial precedent: a mediation analysis of education and graded sensorimotor retraining found the largest indirect effects through back beliefs, catastrophizing, and self-efficacy, with a smaller effect through back self-perception and no support for tactile acuity as a mediator. The author is candid that the incremental value of the broader body-representation domain and the mechanistic independence of the narrower body-schema component remain open empirical questions. What the framework delivers is a rigorous roadmap, converting a diffuse family of observations into specific, disconfirmable predictions that could reshape how chronic back pain is understood and treated.

Subject of Research: Altered body representation, corticomotor function, and pain processing in chronic non-specific low back pain

Article Title: Altered body representation in chronic non-specific low back pain: a testable framework linking body-schema-related disturbance, corticomotor alterations, and altered pain processing

Article References: Xie, Z. (2026). Altered body representation in chronic non-specific low back pain: a testable framework linking body-schema-related disturbance, corticomotor alterations, and altered pain processing. Frontiers in Pain Research, 7, Article 1899538. https://doi.org/10.3389/fpain.2026.1899538

Image Credits: AI Generated

DOI: 10.3389/fpain.2026.1899538

Keywords: chronic low back pain, body schema, body representation, predictive coding, corticomotor control, pain processing, somatosensory cortex, nociplastic pain, central sensitization, transcranial magnetic stimulation, motor imagery, sensorimotor integration

The review begins with a deceptively simple question: how do signals generated by an infection or injury in the body gain access to the brain at all? The answer, the authors explain, involves two complementary routes. The first is neural. Sensory neurons — including spinal afferents with cell bodies in the dorsal root ganglia and cranial afferents housed in the nodose ganglia of the vagus nerve — detect immune molecules and pathogens directly. TRPV1-expressing nociceptors, best known for transmitting pain, can also sense bacterial components and toxins. These neurons relay what the authors call immune information to the brainstem through canonical spinothalamic pathways, providing a rapid, topographically organized mechanism for monitoring physiological threats.

The vagus nerve has emerged as a particularly sophisticated sensory conduit for immune information. Early electrophysiological recordings and c-Fos staining showed that vagal neurons respond to interleukin-1β, but more recent work has revealed a remarkable degree of specificity. Tumor necrosis factor and IL-1β evoke distinct afferent neurograms, and in vivo calcium imaging has shown that pro- and anti-inflammatory cytokines activate two discrete, non-overlapping populations of nodose neurons — one expressing CALCA and the other TRPA1. Individual neurons produce stereotyped, concentration-dependent responses that are cytokine-specific in amplitude and kinetics, with some tuned to a single cytokine and others encoding several through distinct activity patterns. How the vagus achieves this specificity remains unresolved: cultured nodose neurons show surface expression of TNF and IL-1β receptors, yet IL-1 receptor binding sites have also been localized to glomus cells of vagal paraganglia, leaving open whether the neurons themselves or neighboring stromal cells do the sensing.

Vagal afferents project primarily to the nucleus of the solitary tract, the first central site where organ-specific immune signals converge. TRPA1-positive and CALCA-positive afferents synapse monosynaptically onto dopamine β-hydroxylase-expressing neurons in the caudal NTS, which bidirectionally regulate peripheral immune responses and function as a central rheostat balancing pro- and anti-inflammatory reflexes. Repeated allergen exposure activates these same neurons in a vagus-dependent manner, and they relay signals through the nucleus ambiguus to drive airway hyperreactivity. Through projections to the hypothalamus, the NTS also transforms immune signals into sickness behavior: lipopolysaccharide, a bacterial mimic, activates ADCYAP1-positive neurons that are both necessary and sufficient for LPS-induced anorexia, adipsia, and lethargy.

The second route is humoral. Soluble circulating mediators can reach the brain through circumventricular organs, specialized regions that lack a complete blood-brain barrier and are permeable to inflammatory mediators even under homeostatic conditions. Their fenestrated vasculature and efferent projections make them well suited to transduce systemic immune signals into neural activity. Work by Osterhout and colleagues showed that two hallmarks of sickness behavior — fever and appetite suppression — are driven by neurons in the ventral medial preoptic area of the hypothalamus, engaged by a local paracrine mechanism in which non-neuronal cells at the adjacent organum vasculosum of the lamina terminalis detect circulating immune signals and activate nearby VMPO neurons. Beyond this local action, CVOs project directly to regions involved in affective regulation, including the cortex, forming a key anatomical link between circulating cytokines and behaviors associated with affective dysregulation.

Even the intact blood-brain barrier actively participates in this signaling. Endothelial cells and pericytes respond to circulating cytokines by producing secondary messengers such as prostaglandins, which diffuse into the parenchyma and propagate the inflammatory signal into neural tissue. Under strong or prolonged inflammation, the balance shifts from signal transduction toward structural compromise: pro-inflammatory cytokines including TNF and IL-17 induce matrix metalloproteinase activity, driving tight junction remodeling, increased permeability, and ultimately leukocyte infiltration into the brain. These effects are amplified through sphingosine-1-phosphate receptor signaling and chemokine-MMP interactions. Inflammatory states such as sepsis are consistently associated with increased BBB permeability and elevated central cytokine levels, and under chronic stress, MMP8 — a myeloid-derived proteinase elevated in major depressive disorder — can enter the nucleus accumbens, remodel the extracellular space, and alter behavior.

With the delivery routes established, the review turns to the cortical regions that transform these signals into altered behavior. The prefrontal cortex, which supports executive control and behavioral flexibility, is well positioned to receive immune signals: its prelimbic and infralimbic subregions lie close to the immunologically rich meninges and receive projections from circumventricular organs. Allgire and colleagues showed that severe airway inflammation disrupts fear extinction — the suppression of learned fear in the absence of threat, whose failure defines anxiety and trauma-related disorders — through IL-17A signaling in the subfornical organ, a CVO that projects to the infralimbic cortex. Blocking IL-17A or silencing SFO-to-ILA projections restored normal extinction, confirming this circuit as a conduit between peripheral immunity and prefrontal function. PFC neurons also respond directly to cytokines: at homeostasis, meningeal γδ T cell-derived IL-17A engages IL-17Ra on PFC glutamatergic neurons, and neuronal deletion of the receptor reduces anxiety-like behavior, while interferon gamma increases inhibitory input onto pyramidal cells to set baseline anxiety levels. Under challenge, IL-6 alters the intrinsic excitability of PFC neurons and reduces inhibitory input onto pyramidal cells, promoting disinhibition and a social defeat phenotype. Consistent with these rodent findings, postmortem tissue from suicide victims shows elevated proinflammatory cytokine and chemokine expression in the PFC.

The insular cortex, the primary cortical hub for interoceptive processing, offers a complementary mechanism. Immune information likely reaches the IC through the neural pathway relayed via the NTS, parabrachial nucleus, and thalamus, and intestinal infection with Campylobacter jejuni induces c-Fos expression throughout the interoceptive network, including the vagal ganglia, NTS, and IC. Human imaging shows increased activity and microstructural changes in the IC following experimental immune activation, and notably, TNF-α neutralization therapy in patients with arthritis affects IC activity before it achieves anti-inflammatory effects in the joints — suggesting the IC may be among the earliest cortical regions to sense a change in immune state. The IC is especially suited to link inflammation with affective dysregulation because interoceptive signals are actively incorporated into its evaluation of threat: during fear conditioning, cardiac feedback shapes IC activity to balance fear expression and extinction, and artificially imposed tachycardia activates the IC and heightens anxiety, an effect abolished by IC inhibition. The IC therefore treats bodily state as information about external threat, and raising heart rate alone is enough to shift that evaluation. If inflammation is sustained, the same mechanism would report a threat that no longer exists and become maladaptive.

The primary somatosensory cortex adds a third cortical node to the model. Through its connections with the insular cortex and amygdala, S1 integrates sensory information with affective and interoceptive signals, assigning emotional salience to stimuli — particularly pain. The clearest mechanistic example comes from maternal immune activation, in which prenatal immune challenge elevates multiple pro-inflammatory cytokines including IL-17A, IL-6, and interferons, yielding offspring with increased anxiety-related behavior linked to hyperexcitability in the dysgranular zone of S1. Activating excitatory pyramidal neurons in S1DZ is sufficient to reproduce the behavioral phenotype, whereas suppressing them rescues it. Beyond the MIA model, deleting IL-17RA in S1DZ also reduces anxiety, causally linking cytokine signaling in S1 to affective behavior. The same pathway acts adaptively and maladaptively depending on when it is engaged — IL-17RA signaling sets anxiety levels at homeostasis, while developmental IL-17A exposure produces a lasting phenotype.

The behavioral consequences of these cortical changes depend on how the regions communicate with one another and with downstream targets. Both the PFC and IC are reciprocally connected with the amygdala, and dysfunction of these circuits is observed across anxiety disorders, PTSD, and specific phobia. The prelimbic cortex facilitates fear expression, whereas the infralimbic cortex suppresses fear and supports extinction. Optogenetic manipulation of a posterior IC-to-central amygdala pathway bidirectionally alters anxiety-like behavior, while anterior IC-to-BLA projections are activated during exploration of anxiogenic environments and are themselves anxiogenic. In the complete Freund’s adjuvant inflammatory pain model, IC-BLA connectivity is reportedly enhanced, and S1 projections to the caudal dorsolateral striatum drive comorbid anxiety in that same model, while S1 projections to the parafascicular thalamus contribute to anxiety-like behavior after formalin-induced acute inflammatory pain. However, the authors emphasize that causality for the PFC-amygdala and IC-BLA pathways under peripheral inflammation has not yet been established — these are established routes by which cortical changes are translated into altered affective states, but mostly inferred conduits for inflammation.

The review’s synthesis carries a striking evolutionary logic: the immune and emotional systems are tightly coupled survival mechanisms, with emotion assigning salience to threats and coordinating the physiological and behavioral responses required for effective immune defense. Acutely, the processes described are adaptive — hypervigilance and avoidance limit further exposure and prioritize recovery. When dysregulated, as in chronic or recurrent inflammation, the same signaling turns maladaptive, and anxiety emerges from altered representations of internal physiological state. The traffic is not one-way: reactivating insular cortex ensembles tagged during zymosan-induced peritonitis and dextran sulfate sodium-induced colitis is sufficient to reinstate inflammation in the same peripheral tissues originally affected, meaning the IC both monitors peripheral immune state and contributes to its anticipatory regulation. Whether the circuits that bias affect toward threat overlap with those that regulate immunity remains unresolved. The authors identify as a central open question which inflammatory conditions engage which circuits, and whether distinct immune challenges converge on shared substrates or recruit dedicated ones. Resolving this specificity, they argue, is essential to explain why inflammation produces heterogeneous psychiatric presentations — and if discrete circuits mediate the affective consequences of inflammation, they offer promising targets for interrupting the path from immune activation to maladaptive affective dysregulation.

Subject of Research: How peripheral inflammatory signals reach and alter cortical circuits governing anxiety and depression

Article Title: Cortical circuits linking peripheral inflammation to affective states

Article References: Jun, D. J., Tang, S., & Favuzzi, E. (2026). Cortical circuits linking peripheral inflammation to affective states. Frontiers in Cellular Neuroscience, 20, Article 1951226. https://doi.org/10.3389/fncel.2026.1951226

Image Credits: AI Generated

DOI: 10.3389/fncel.2026.1951226

Keywords: inflammation, cortex, anxiety, depression, vagus nerve, cytokines, prefrontal cortex, insular cortex, somatosensory cortex, blood-brain barrier, interoception, neuroimmune

The cortical territory devoted to each finger is tiny, occupying millimetre-scale patches along a folded strip of tissue called the primary somatosensory cortex, tucked into the postcentral gyrus. Resolving individual finger representations demands both exceptional spatial resolution and clever experimental design. Earlier studies, many conducted at 3 Tesla or below, reported that dystonia patients had blurred, overlapping finger maps, with reduced distances between neighbouring digit representations. Those findings have been increasingly questioned, because coarse resolution and volumetric analyses can distort measurements across the brain’s folds. The Nottingham group therefore turned to 7T fMRI, whose stronger magnetic field yields greater blood-oxygenation-level-dependent contrast and finer spatial detail, and analysed the data on the cortical surface rather than in three-dimensional volume space.

The experimental centerpiece was a travelling-wave paradigm. Piezoelectric stimulators attached to the fingertips vibrated each digit in turn at 30 hertz in a smoothly cycling sequence, so that the phase of the fMRI signal in each cortical vertex encoded which finger it represented. Fourier analysis of the resulting time series produced coherence and phase maps tracing the orderly progression from thumb to little finger. The researchers also ran a motor travelling-wave task on the dominant hand, compared every participant’s maps against a probabilistic digit atlas built from healthy volunteers, and fitted a one-dimensional Gaussian population receptive field model to estimate how broadly each cortical location responded to touch.

Four patients with focal hand dystonia, all with writer’s cramp affecting their dominant hand, completed the full protocol twice: once roughly thirty days after a botulinum toxin injection, at peak drug efficacy, and again roughly one hundred days after treatment, just before their next injection when the therapeutic effect had waned. Age- and sex-matched healthy controls were scanned once. Alongside imaging, participants completed behavioural tests of temporal discrimination, vibrotactile amplitude detection, and spatial acuity using a grating orientation task, in which participants judge the orientation of ridged domes pressed against a fingertip. Ten additional volunteers repeated the behavioural battery two weeks apart so that the team could verify each measure’s repeatability.

On the behavioural side, one result stood out clearly. Spatial acuity, measured by the grating orientation task, was significantly worse in the dystonic, dominant hand than in controls, at both post-treatment and pre-treatment visits. Temporal discrimination and amplitude detection, by contrast, showed no significant differences between groups, likely reflecting the greater variability of those measures and the small sample. The repeatability checks confirmed that the grating task was by far the most stable behavioural metric, with a within-participant coefficient of variation of just over six percent, making it a reliable probe of the sensory deficits that many researchers now consider central to dystonia’s pathophysiology.

Inside the scanner, the headline finding was nuanced. Contrary to the earliest reports of widespread map collapse, the digit maps of dystonia patients retained their classic thumb-to-little-finger ordering in both somatosensory and motor cortex, and looked qualitatively similar to those of healthy volunteers. But quantitative comparisons told a subtler story. Dice coefficients, which quantify the spatial overlap between each participant’s digit regions of interest and a reference, were significantly lower for the affected dominant hand than for the non-dominant hand, in both the somatosensory and motor tasks, when patients were compared with controls. A figure-of-merit summary that penalises degenerate, overlapping representations confirmed the pattern. The cortex had not scrambled its hand, but the affected hand’s representation was measurably more disordered or variable.

The population receptive field analysis delivered the study’s most striking treatment-related result. In the period just before the next injection, when botulinum toxin’s effects had declined, patients’ pRF sizes in the dominant hand were significantly larger than in controls and than in the same patients at peak treatment. Larger pRFs mean that each cortical patch pools touch information from a wider swath of the fingertip, a blurrier, less finely tuned representation. After treatment, pRF sizes shrank back to values comparable with healthy controls. Notably, the large-scale digit ordering captured by Dice coefficients and central-tendency metrics did not change between visits, suggesting the toxin modulates fine-grained spatial tuning rather than reorganising the map wholesale.

Resting-state fMRI added a network-level perspective. With seeds placed in the postcentral gyrus, the team found reduced functional connectivity between the hemisphere contralateral to the dominant hand and the opposite postcentral gyrus in patients, consistent with prior reports of weakened sensorimotor connectivity in writer’s cramp and other dystonias. No connectivity differences emerged between the two treatment time points, which the authors attribute to the limited statistical power of a four-patient imaging cohort rather than a genuine absence of effect. The findings echo a broader shift in dystonia research away from viewing the disorder as a basal ganglia problem alone and toward understanding it as a disorder of distributed sensorimotor networks.

The implications of the pRF result are provocative. Botulinum toxin acts peripherally, blocking acetylcholine release at the neuromuscular junction and quieting overactive muscles. Yet the cortical tuning it coincided with suggests a central echo of a peripheral intervention: as abnormal muscle activity and afferent feedback subside, the somatosensory cortex may sharpen its receptive fields. This fits accumulating evidence that focal hand dystonia is fundamentally a disorder of abnormal sensorimotor integration, in which distorted sensory input and maladaptive plasticity reinforce each other. If pRF size proves to be a sensitive, treatment-responsive biomarker, it could eventually help clinicians and researchers measure how therapies act on the brain, not just on the muscle.

The authors are candid about the study’s limits. Four patients made it through the strict imaging quality controls, small numbers that constrain statistical power and raise the risk of false positives despite Bonferroni correction, and patient heterogeneity in symptom duration and severity complicates group comparisons. The grating task was administered only to the affected hand, and the motor mapping only to the dominant hand, limiting within-participant comparisons. Larger cohorts, both-hand motor mapping, and correlation of pRF measures with individual symptoms are the obvious next steps. Even so, the study makes a compelling case that 7T fMRI, surface-based analysis, and computational modelling can detect subtle, treatment-linked changes in the brain’s hand map that older techniques missed, and that a drug best known for freezing muscles may quietly retune the cortex that feels them.

Subject of Research: Cortical digit map organisation and botulinum toxin effects in focal hand dystonia measured with 7T functional MRI

Article Title: Assessing the digit organisation of focal hand dystonia using 7T functional MRI

Article References: Asghar, M., Sanchez-Panchuelo, R., Glover, P., Pakenham, D., O’Neill, G. C., Schluppeck, D., Humberstone, M., & Francis, S. (2026). Assessing the digit organisation of focal hand dystonia using 7T functional MRI. Dystonia, 5, Article 15574. https://doi.org/10.3389/dyst.2026.15574

Image Credits: AI Generated

DOI: 10.3389/dyst.2026.15574

Keywords: focal hand dystonia, botulinum toxin, 7T fMRI, somatosensory cortex, digit mapping, population receptive field, writer's cramp, functional connectivity, travelling wave fMRI, spatial acuity, neuroplasticity, Dystonia journal

The research team, led by Robin Kamrla and Konrad Schöniger of Martin Luther University Halle-Wittenberg, analyzed structural MRI scans and questionnaire data from 261 healthy adults aged 18 to 64. Participants completed the German version of the Freiburg Mindfulness Inventory, a 14-item questionnaire that yields separate scores for presence and acceptance, alongside clinical interviews and standardized measures of depression and anxiety. All participants were free of current psychiatric diagnoses and psychotropic medication, allowing the researchers to examine how everyday differences in trait mindfulness map onto brain structure in a non-clinical population.

What set this study apart was its analytical strategy. Rather than correlating each mindfulness subscale with brain structure separately — the approach taken by most previous work — the team built a single multiple regression model that included both subscales simultaneously and then explicitly tested for regions where the two moved in opposite directions. This differential dissociation approach directly asks whether a brain region grows with one component while shrinking with the other, a pattern that would be invisible, or even misleadingly averaged away, in conventional univariate analyses. Grey matter volume was estimated with voxel-based morphometry using high-resolution T1-weighted images acquired on a 3 Tesla scanner, and results were corrected for multiple comparisons using non-parametric threshold-free cluster enhancement with 5,000 permutations.

The results revealed a striking split. Acceptance, measured by items such as being friendly to oneself when things go wrong, correlated positively with grey matter volume in the left rolandic operculum and the left postcentral gyrus — regions that make up the primary and secondary somatosensory cortex, the brain’s machinery for perceiving bodily and sensory signals. Presence, by contrast, was negatively associated with grey matter in those same cortical areas. In other words, the more a participant scored on acceptance relative to presence, the larger the volume of their somatosensory regions; the more they scored on presence relative to acceptance, the smaller those volumes appeared.

The second direction of dissociation produced an equally compelling finding, this time in the limbic system. Within a targeted region-of-interest analysis of the amygdala, the almond-shaped structure central to emotion perception and threat processing, grey matter volume in the right hemisphere was negatively correlated with acceptance and positively correlated with presence. Higher presence paired with lower acceptance was associated with a larger amygdala, while higher acceptance with lower presence accompanied a smaller one. This pattern echoes the Monitor and Acceptance Theory of mindfulness proposed by Lindsay and Creswell in 2017, which holds that monitoring — the presence-like component — can intensify all experiences, negative, positive, and neutral alike, whereas acceptance dampens affective reactivity and counterbalances that amplification.

The psychometric data reinforced the neural story. Acceptance scores correlated strongly and negatively with both depression and anxiety symptoms, and these relationships held even after statistically controlling for presence. Presence, meanwhile, showed correlations with depression and anxiety that vanished entirely once acceptance was taken into account. This mirrors the earlier work of Kohls and colleagues, who found that only acceptance, not presence, was linked to reduced anxiety and depression — the very conditions for which mindfulness-based interventions appear most effective. The new study extends that dissociation from questionnaires to brain anatomy, suggesting that the clinical benefits of mindfulness may flow primarily through acceptance-related neural circuits.

Post-hoc analyses sharpened the picture further. When each subscale was examined separately while controlling for the other, acceptance was associated with grey matter in the bilateral rolandic operculum, bilateral postcentral gyrus, supplementary motor area, cingulate cortex, and precuneus, as well as limbic structures including the right amygdala, parahippocampal gyrus, and superior temporal pole. Presence, in its unique variance, was linked to negative associations in somatosensory and auditory regions such as Heschl’s gyrus. The researchers interpret this as evidence that acceptance is tied to the deep, non-judgmental processing of bodily sensations and emotions, whereas presence reflects the capacity for intentional shifts of attention — a refocusing skill that, on its own, does not engage the emotion-integration circuitry.

The authors are careful about what these structural correlations can and cannot mean. Grey matter volume is an indirect marker, mediated by factors such as neural efficiency and plasticity, and the study’s cross-sectional design cannot determine whether brain shape shapes mindfulness or mindfulness practice reshapes the brain. The sample was also predominantly young and healthy, limiting generalizability to clinical populations, and individual meditation experience was not assessed. The researchers themselves note that the study was not preregistered and that their post-hoc analyses captured only the variance unique to each subscale, not the substantial portion the two share — the subscales correlated at r = 0.56 in this sample.

Even with those caveats, the implications are considerable. If mindfulness is treated as a single unified construct, interventions may inadvertently train the wrong component for the wrong goal. Someone high in presence but low in acceptance might, according to the Monitor and Acceptance Theory, experience heightened affective reactivity — attending intensely to everything without the emotional integration that acceptance provides. The new neurostructural findings give that theoretical framework an anatomical footing: presence was associated only with neocortical regions, while acceptance reached into the limbic system in the opposite polarity. The two subdomains, the authors argue, may function as complementary and partially compensatory mechanisms within the broader mindfulness construct.

Future work, the team suggests, should test whether the same dissociation appears in functional MRI responses to emotional stimuli, and whether longitudinal or intervention-based designs can establish causal relationships between meditation practice, acceptance, and limbic structure. The differential analysis framework itself may prove portable, offering a template for teasing apart compensatory mechanisms in other psychological constructs that have been lumped together under single labels. For now, the message for both scientists and practitioners is clear: the mindful brain is not one thing. Being fully present and being fully accepting recruit different, and in places opposing, neural signatures — and understanding that duality may be the key to explaining why mindfulness helps some minds and, occasionally, intensifies the experience of others.

Subject of Research: Neurostructural correlates of the presence and acceptance subdomains of trait mindfulness in healthy adults

Article Title: Neural Correlates of Dissociating Mindfulness Subdomains: A Differential Analysis Approach

Article References: Kamrla, R., Schöniger, K., König, P., Zwiky, E., Küttner, A., Scheiwe, G. S., Andreev, J., Fleischer, L., Uhlig, M., Ptasczynski, L. E., Spitzer, M., Deistung, A., Wohlgemuth, W. A., Selle, J., & Redlich, R. (2026). Neural Correlates of Dissociating Mindfulness Subdomains: A Differential Analysis Approach. Mindfulness. https://doi.org/10.1007/s12671-026-02993-6

Image Credits: AI Generated

DOI: 10.1007/s12671-026-02993-6

Keywords: mindfulness, presence, acceptance, grey matter volume, amygdala, voxel-based morphometry, Freiburg Mindfulness Inventory, Monitor and Acceptance Theory, somatosensory cortex, emotion regulation, structural MRI, trait mindfulness

Bulimia nervosa is a serious psychiatric condition characterized by recurrent episodes of binge eating followed by compensatory behaviors such as purging, along with intense preoccupation with body shape and weight. The disorder carries substantial medical and psychological burden, and while enhanced cognitive behavioral therapy, known as CBT-E, remains the first-line intervention, remission rates remain stubbornly modest. This treatment gap has driven researchers to ask a fundamental question: what changes in the brain when therapy succeeds, and can those changes, or the brain’s starting configuration, tell us who is likely to respond?

To investigate, researchers affiliated with the Eating Disorder Neuroimaging Initiative recruited thirty Japanese women with bulimia nervosa, with an average age of 33.6 years. The participants received one of three CBT-based treatments delivered across multiple sites: twenty-four received enhanced CBT in person, four received CBT via videoconference, and two completed guided internet-based CBT. Each woman underwent resting-state functional magnetic resonance imaging and completed symptom assessments, including the Eating Disorder Examination Questionnaire, both before and after treatment, with an average interval of 5.6 months between scans.

Resting-state functional connectivity, the technique at the heart of the study, measures how spontaneously synchronized activity is between brain regions when a person is simply lying still in the scanner. Rather than probing task-driven brain responses, it captures the intrinsic wiring diagram of the brain, offering a window into the circuit organization that persists across mental states. The researchers computed connectivity between pairs of predefined regions of interest across the whole brain and used statistical harmonization procedures to remove site-specific differences introduced by the multi-center design, a critical step for ensuring that scanner effects did not masquerade as clinical findings.

The analysis then asked two complementary questions. First, did changes in connectivity between the pre- and post-treatment scans track the degree of symptom improvement measured by the questionnaire? Second, did the strength of specific connections before treatment predict how much a patient would improve? The team used multiple regression models that adjusted for age and pretreatment psychotropic medication, and they applied false discovery rate correction at two levels: a seed-level correction across all connections emanating from each region, and a stricter analysis-level correction across every tested connection in the study.

Under the most conservative statistical threshold, no individual connection survived correction, a sobering but honest result that the authors emphasize throughout. However, at the exploratory seed level, a coherent pattern emerged. Greater improvement in eating disorder symptoms was associated with decreased connectivity between the right orbitofrontal cortex, a region central to reward valuation and decision-making, and the right posterior supramarginal gyrus, which participates in integrating sensory and bodily information. Improvement was also linked to increased connectivity between the right anterior temporal fusiform cortex and cerebellar regions, and between the right caudate nucleus, a key node of the basal ganglia reward system, and the right cerebellar hemisphere IX.

These circuits are not random. The orbitofrontal cortex and caudate nucleus have long been implicated in the aberrant reward processing thought to drive binge eating and purging, while the cerebellum is increasingly recognized as far more than a motor structure, contributing to cognitive and affective regulation. The finding that symptom improvement accompanied a loosening of orbitofrontal connections and a strengthening of striatal-cerebellar coupling suggests that successful therapy may reorganize how reward signals are computed and propagated through the brain, potentially dampening the pathological valuation of food and body shape that sustains the disorder.

Equally intriguing were the pretreatment predictors. Women who improved more showed stronger baseline connectivity between the right superior parietal lobule and inferior frontal and temporo-occipital regions, as well as between the left postcentral gyrus and bilateral inferior temporal gyri. The postcentral gyrus houses the primary somatosensory cortex, which represents the body’s physical form, while the superior parietal lobule supports spatial attention and cognitive control. Stronger connectivity in these networks before therapy may reflect a neural readiness, a capacity for body-awareness integration and self-regulation that allows patients to engage more fully with the cognitive restructuring work that CBT demands.

The researchers are careful to frame these results as preliminary. The sample of thirty participants is small, there was no healthy control group, and the findings did not survive the strictest multiple-comparison correction. Resting-state connectivity measures are also sensitive to head motion and physiological noise, and the mixed treatment modalities, while all CBT-based, introduce heterogeneity. Replication in larger, controlled cohorts is essential before these connectivity signatures could inform clinical practice. Still, the study’s multi-site harmonized design and longitudinal structure represent methodological advances over the cross-sectional snapshots that have dominated the field.

The broader significance lies in what this line of research could eventually deliver: biomarkers that identify patients at risk of treatment failure before therapy begins, and mechanistic targets for interventions that directly modulate the circuits involved. Brain stimulation techniques, neurofeedback, and digitally delivered therapies could all be refined by a clearer map of the neural substrate of recovery. For now, the study offers a cautious but compelling glimpse of the brain rewiring itself as patients heal, suggesting that the path out of bulimia nervosa may be written, in part, in the changing conversation between the reward system, the body’s sensory maps, and the mind’s capacity for control.

Subject of Research: Resting-state functional connectivity changes and pretreatment predictors of cognitive behavioral therapy response in bulimia nervosa

Article Title: Resting-state functional connectivity changes and pretreatment features associated with symptom improvement after cognitive behavioral therapy for bulimia nervosa

Article References: Sudo, Y., Chhatkuli, R. B., Takamura, T., Kamashita, R., Matsumoto, K., Numata, N., Hamatani, S., Moriguchi, Y., Ino, K., Ando, T., Ohara, C., Funaba, M., Isobe, M., Noda, T., Tose, K., Murai, T., Sunada, M., Morimoto, K., Taniguchi, M., … Futatsuya, K. (2026). Resting-state functional connectivity changes and pretreatment features associated with symptom improvement after cognitive behavioral therapy for bulimia nervosa. Journal of Eating Disorders. https://doi.org/10.1186/s40337-026-01754-z

Image Credits: AI Generated

DOI: 10.1186/s40337-026-01754-z

Keywords: bulimia nervosa, cognitive behavioral therapy, resting-state functional connectivity, fMRI, reward processing, somatosensory cortex, orbitofrontal cortex, cerebellum, treatment response, eating disorders, neuroimaging, predictive biomarkers

Sensory gating is one of the nervous system’s most economical tricks. When two identical stimuli arrive in quick succession, the brain’s response to the second is normally dampened relative to the first, a phenomenon measured by the ratio of the second response to the first. This suppression is not fixed; it depends heavily on the interstimulus interval, the gap between the two pulses. At very short intervals the cortical circuitry is still recovering and the second response is strongly attenuated, while at longer intervals the response gradually rebounds. The pattern reflects the recovery dynamics of thalamocortical synapses and local inhibitory circuits, and it allows the cortex to emphasize novel input while suppressing redundant input. In clinical settings, disturbances of sensory gating have been linked to a range of conditions, from migraine to schizophrenia, making the mechanism a sensitive readout of brain health.

To test how sustained pain reshapes this system, the team applied paired-pulse electrical stimulation to the median nerve of anesthetized rats, delivering two pulses separated by interstimulus intervals of 35, 50, 80, 140, and 500 milliseconds. Evoked potentials were recorded directly from the primary somatosensory cortex, the cortical region that receives and processes touch and proprioceptive information from the body. The researchers then injected capsaicin, the pungent compound in chili peppers that activates TRPV1 receptors on nociceptive C-fibers, into the territory served by the nerve. Capsaicin produces a well-characterized model of sustained peripheral nociceptive input: it does not destroy the nerve, but it drives a prolonged barrage of pain-related signals from the periphery into the central nervous system. Recordings were repeated at 60 and 120 minutes after the injection, allowing the team to track how the cortical response evolved as the pain signal persisted.

The results were striking in their asymmetry. Compared with vehicle-treated controls, capsaicin significantly increased the amplitude and the area under the curve of the first response, S1, while simultaneously decreasing the S2/S1 amplitude ratio across the entire two-hour recording window. In other words, the cortex responded more vigorously to the initial stimulus, but the relative suppression of the second stimulus deepened. At first glance that combination may seem paradoxical, but the authors interpret it as a change in response gain: the whole input-output function of the cortical circuit was scaled up, so the first response grew while the recovery-dependent second response failed to keep pace. Crucially, this effect appeared to be independent of the interstimulus interval. In the normal brain, the degree of gating varies systematically with the gap between pulses; after capsaicin, that orderly interval-dependent structure was largely lost, replaced by a flattened, interval-insensitive profile.

The study went beyond conventional evoked potentials by examining high-frequency oscillations, or HFOs, the fast rhythmic components superimposed on somatosensory evoked responses. These oscillations are thought to arise from distinct neuronal generators, with early components reflecting activity in inhibitory interneuron networks and later components tied to thalamocortical relay activity. When the researchers decomposed the evoked responses into frequency bands, they found that both the early and late components of the S1 response were significantly increased in the 50 to 150 Hz domain after capsaicin. Even more notably, the early component of the area under the S1 response increased prominently in the 400 to 800 Hz band, an extremely fast range that is rarely accessible in routine human recordings but can be resolved with direct cortical electrodes in animal models.

These frequency-specific changes carry physiological weight. The 50 to 150 Hz range overlaps with gamma-band activity, which is associated with local cortical processing and has been implicated in pain-related cortical dynamics in both animal and human studies. The 400 to 800 Hz bursts, sometimes called very high-frequency oscillations, are believed to index the firing of populations of inhibitory interneurons in the superficial layers of the cortex. A disproportionate amplification of the early, very high-frequency component of S1 suggests that sustained nociceptive input acts at the earliest stages of cortical sensory processing, altering the excitability of the local inhibitory network before the signal is even relayed through the canonical cortical columns. The authors propose that capsaicin-induced nociceptive drive modified the response gain of the cortex while simultaneously abolishing the normal interval-dependent recovery function, a dual insult that degrades the brain’s ability to temporally parse incoming sensory information.

Why does this matter for understanding chronic pain? Temporal discrimination, the ability to distinguish two stimuli that arrive close together in time, depends on precisely the gating mechanism the study measured. Patients with neuropathic pain and other chronic pain conditions frequently report allodynia, hyperalgesia, and difficulty separating simultaneous sensations, symptoms that could plausibly arise from a cortex whose gain has been turned up and whose interval-dependent filter has been disabled. The current findings provide an electrophysiological substrate for those clinical observations: sustained peripheral nociceptive input does not merely add a painful signal on top of normal processing, it reorganizes the processing itself. The disproportionate effect on S1, the initial cortical response, points to early sensory processing as a key site of pain-related plasticity, rather than the higher-order associative regions that have traditionally attracted most attention.

The methodology deserves attention as well. By sampling five interstimulus intervals spanning more than a fourteenfold range, from 35 to 500 milliseconds, and by recording at two time points after the nociceptive challenge, the experiment captured both the temporal structure and the time course of the gating disruption. The finding that capsaicin’s effects did not vary meaningfully with interval values was itself an important negative result: the authors state that they could not clearly detect a significant contribution of ISI values to capsaicin’s effects on sensory processing regulation. That absence of interval dependence is precisely what one would expect if sustained nociceptive input had overwritten the recovery dynamics of the thalamocortical circuit, replacing a tuned filter with a uniformly amplified, uniformly suppressed regime.

There are, of course, limits to what an anesthetized rat model can tell us about human pain perception. Capsaicin injection is an acute model of sustained nociception rather than a true chronic pain state, and cortical responses recorded under anesthesia may differ in important ways from those in a behaving, conscious animal. The authors also note that the study was conducted without external funding, and the work was approved by the Gazi University Local Ethics Committee for Animal Experiments. Nevertheless, the model has strong translational precedent, and the electrophysiological markers identified here, particularly the S2/S1 ratio and the high-frequency oscillation profile, have direct analogues in human somatosensory evoked potential recordings, raising the possibility of biomarkers for pain-related cortical dysfunction.

The broader lesson is that pain is not just a sensation; it is a modulator of sensation. By driving a sustained stream of nociceptive traffic into the thalamocortical system, a persistent pain source appears to hijack the gain control and temporal filtering that the cortex relies on to organize all incoming sensory information. If confirmed in further studies, this mechanism could help explain the sensory chaos that many chronic pain patients describe, and it suggests that therapies aimed at restoring normal cortical gating, rather than simply blocking pain signals at their source, might offer a route to relieving the full burden of the condition. For now, the rat cortex has delivered a clear message: when pain will not stop talking, the brain stops listening properly to everything else.

Subject of Research: Effects of sustained peripheral nociceptive input on sensory gating in the rat primary somatosensory cortex

Article Title: Sustained peripheral nociceptive input disrupts interstimulus-interval-dependent sensory gating in the rat primary somatosensory cortex

Article References: Tepe, N., Boran, H. E., Geduk, S., Dileköz, E., Sara, Y., & Bolay, H. (2026). Sustained peripheral nociceptive input disrupts interstimulus-interval-dependent sensory gating in the rat primary somatosensory cortex. BMC Neuroscience. https://doi.org/10.1186/s12868-026-01053-y

Image Credits: AI Generated

DOI: 10.1186/s12868-026-01053-y

Keywords: sensory gating, chronic pain, capsaicin, somatosensory cortex, high-frequency oscillations, interstimulus interval, nociception, thalamocortical pathway, evoked potentials, neurophysiology, TRPV1, BMC Neuroscience

The technical premise of ICMS is deceptively simple. By passing carefully shaped pulses of electrical current through microelectrodes positioned in cortical tissue, researchers can evoke neural activity in targeted populations of neurons without requiring any natural sensory input. The timing, amplitude, frequency and spatial pattern of those pulses determine what the brain perceives. In a functioning brain-computer interface, this creates the possibility of a true two-way channel: the device decodes neural signals to infer intent, and it writes information back into the cortex through stimulation. The Tianjin University review, authored by Pengfei Hu, Chong Chen, Yunliang Zang, Xiaohong Li and Dong Ming, organizes the field around this delivery-and-parameter framework, tracing how pulse design and electrode placement jointly shape both perception and long-term circuit change.

The most direct and best-documented application is artificial touch. When electrodes stimulate the primary somatosensory cortex, human participants report localized sensations described as touch, pressure or tingling at specific points on the body, even though no peripheral nerve is involved. Early experiments established that individual electrodes reliably produce perceptible, place-specific sensations. More recent work has pushed further, using multiple electrodes and engineered spatiotemporal patterns to convey richer tactile information, including edges, curvature and even apparent motion across the skin. Human studies have shown that such patterned stimulation improves the controllability and internal structure of artificial touch, allowing users to discriminate features that single-pulse stimulation cannot convey. Yet the review is candid about the gap that remains: synthetic tactile signals still do not reproduce the complexity of natural touch, which combines thousands of mechanoreceptors firing with precisely coordinated timing.

Vision follows a parallel logic. Electrical stimulation of the primary visual cortex produces phosphenes, the perceived spots or lines of light that appear even in people who have been blind for years. Because phosphenes can be evoked across a grid of electrodes, coordinated stimulation of multiple sites can be composed into recognizable shapes and letters, much as individual pixels combine into an image. Experiments with blind participants have demonstrated simple two-dimensional visual patterns and basic object-localization tasks, offering proof of principle that cortical prostheses can deliver usable visual information. Still, the researchers note that current visual prosthesis studies remain confined to relatively simple shapes, letters and localization. Predicting how a given stimulation will be perceived, identifying which electrode combinations produce the most useful phosphenes, and maintaining stable stimulation over long implantation periods remain the field’s most stubborn engineering challenges.

One of the most consequential findings the review synthesizes is that the brain can learn. Animals trained with intracortical stimulation learn to interpret artificial patterns and use them to guide behavior, even when those patterns bear no direct resemblance to natural sensory codes. This observation suggests that the nervous system does not demand an exact mimicry of biology; it can assign meaning to an entirely synthetic neural signal through experience. The implications for future bidirectional brain-computer interfaces are substantial. Rather than painstakingly reverse-engineering natural sensory encoding, engineers may be able to design stimulation schemes that are simpler, more robust and more flexible, and trust cortical plasticity to do the interpretive work. The brain, in effect, becomes a co-designer of the interface.

The review then examines a more ambitious possibility: using ICMS not merely to create momentary sensations but to change how neural circuits function over longer periods. Repeated or precisely timed stimulation can induce plasticity-like changes in cortical networks, the same class of modifications through which the brain normally stores skills and recovers from injury. The authors discuss studies in which paired or activity-dependent stimulation altered functional connectivity between cortical regions. In one particularly striking closed-loop paradigm, spontaneous neural activity recorded from the motor cortex was used to trigger stimulation of the somatosensory cortex with a controlled delay. Because the stimulation arrived at a biologically meaningful time relative to the spontaneous activity, the temporally matched pairing strengthened intercortical coupling and was associated with improved motor recovery in a rat model of brain injury. The result points toward stimulation therapies that reshape circuits rather than simply activating them.

Despite these advances, the authors are explicit that such applications remain largely experimental. Reliable biomarkers that confirm a circuit has actually changed, reproducible stimulation parameters that work across individuals, implantation procedures that are safe over years, and therapeutic benefits that endure all require further validation before any clinical translation. The history of neuromodulation is littered with promising animal results that failed to survive the transition to human trials, and ICMS researchers are aware that plasticity induction, in particular, is exquisitely sensitive to timing, dosage and the state of the tissue being stimulated. What works in a healthy rat motor-sensory loop may behave very differently in an injured or aged human cortex.

A parallel challenge is the hardware itself. Conventional microwire and silicon electrodes are far stiffer than the soft, delicate tissue of the brain, and this mechanical mismatch has consequences. Micromotion between implant and tissue causes damage, inflammation and glial scar formation, which progressively isolate the electrode from the neurons it needs to reach and degrade signal quality over time. Flexible electrodes soften the mechanical mismatch, and the review describes the field’s migration from rigid probes toward flexible, biomimetic designs. But flexibility alone cannot eliminate the biological barrier between an artificial material and living neural tissue, which is why the researchers highlight a further step: biohybrid neural interfaces. These incorporate living biological components, including neural stem cells, neural progenitor cells and other neural cells, directly into the implanted device. The goal is twofold: improve integration with host tissue so the interface survives longer, and allow living tissue to participate in signal transmission itself. More advanced designs can even guide axon growth, creating new biological connections between neural tissue and the electronic device. In the most optimistic framing, biohybrid interfaces could extend beyond better electrodes to repairing damaged neural circuits, combining electronics, living cells and host tissue into a single functioning system.

None of this, the review stresses, makes ICMS a plug-and-play technology. Long-term performance depends on the stability of implanted electrodes, and stimulation effects vary between individuals and can drift over time within the same person. The authors therefore call for coordinated progress across electrode design, stimulation encoding, closed-loop calibration and safety evaluation, together with longer follow-up periods, cross-species validation, standardized safety assessments and reproducible behavioral and neural-network outcomes. Rather than replacing existing neuromodulation technologies, they argue, ICMS may ultimately serve as a complementary tool offering far finer control over local neural populations than surface stimulation or pharmacological approaches can achieve. Its long-term promise lies in combining several capabilities at once: delivering artificial sensory information, letting the brain learn entirely new information channels, reshaping dysfunctional circuits and integrating electronic devices more naturally with living neural tissue. As the review concludes, translating intracortical microstimulation from an experimental technique into durable brain-computer interface systems will require progress not in any single technology, but simultaneously across interface reliability, stimulation encoding, closed-loop control, safety and biohybrid integration. The work was supported by the National Key Research and Development Program of China, the Major Program of the National Natural Science Foundation of China and the National Natural Science Foundation of China.

Subject of Research: Intracortical microstimulation as a technique for evoking artificial perception and inducing plasticity in brain-computer interfaces

Article Title: Intracortical microstimulation in brain–computer interfaces: Evoking perception and plasticity

Article References: Intracortical microstimulation in brain–computer interfaces: Evoking perception and plasticity. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: intracortical microstimulation, brain-computer interfaces, sensory feedback, phosphenes, neuroplasticity, closed-loop neuromodulation, biohybrid neural interfaces, somatosensory cortex, visual prosthesis, neural electrodes, Intracortical, microstimulation

Balance is one of the most demanding tasks the aging brain performs. Every second of standing involves a continuous negotiation between sensory feedback from the feet, joints, and vestibular system and motor commands that make millimeter-scale corrections to keep the body’s center of mass over its base of support. As people age, this negotiation becomes less reliable, and falls become a leading cause of injury and loss of independence. Postural scientists often quantify stability by tracking the center of pressure, the point at which the ground reaction force passes under the feet. A wandering, jittery center of pressure trajectory signals effortful, corrective balance control, while a smooth trajectory reflects a system that anticipates and manages perturbations before they become threats.

To probe how Tai Chi might influence this system, the research team recruited thirty-six older adults with substantial Tai Chi experience and twenty-five age-matched healthy older adults with no Tai Chi background. Participants performed four standing tasks of increasing difficulty: a quiet stance with feet comfortably apart, a narrow stance with feet brought close together, and a tandem stance performed twice, once with the left leg forward and once with the right leg forward. Each configuration progressively shrinks the base of support and forces the postural control system to work harder, which allowed the researchers to observe how the brain and body respond as stability becomes more precarious.

The technological centerpiece of the study was functional near-infrared spectroscopy, a non-invasive optical technique that measures changes in oxygenated hemoglobin in the outer layers of the brain. Because neurons that are actively firing demand more oxygen, shifts in hemoglobin concentration serve as a proxy for cortical activation. Unlike functional MRI, fNIRS allows participants to stand, sway, and shift weight naturally, making it well suited to studying posture in real time. The researchers focused on a network of regions of interest critical to movement: the primary motor cortex, which issues motor commands; the primary somatosensory cortex, which integrates body-position feedback; the supplementary motor area, which plans and sequences movement; and the dorsolateral prefrontal cortex, which contributes attention and executive control to demanding tasks.

The results revealed a consistent pattern of cortical advantage among the Tai Chi practitioners. Compared with controls, they showed greater activation in the left primary somatosensory cortex during the tandem stance with the left leg forward, greater activation in the right dorsolateral prefrontal cortex during the narrow stance, and elevated activation in the right primary motor cortex during both the narrow stance and the tandem stance. These differences were statistically robust, with p-values ranging from 0.02 to below 0.01. Perhaps more striking, the practitioners displayed stronger functional connectivity, both within and between the primary motor cortex, the primary somatosensory cortex, and the supplementary motor area, with all comparisons reaching significance at p below 0.05. In practical terms, the brain regions responsible for sensing the body and commanding movement were talking to each other more coherently in the Tai Chi group.

The researchers interpret this enhanced coordination as cortical synchronization, a state in which sensorimotor regions operate as an integrated unit rather than as loosely coupled specialists. Such synchronization is thought to reflect neural efficiency: when communication between sensory and motor areas is strong, the brain can detect a loss of balance earlier and issue corrective commands with less delay and less compensatory recruitment of higher cognitive regions. The elevated prefrontal activation seen in practitioners during the narrow stance may indicate that experienced Tai Chi practitioners can flexibly bring attentional resources to bear precisely when a task becomes difficult, a capacity that often declines with age and is strongly linked to fall risk.

The behavioral side of the study told an equally compelling story. On the Berg Balance Scale, a widely used clinical measure of functional balance, the Tai Chi practitioners scored significantly higher than the non-practitioners, with p below 0.01. Analysis of center of pressure recordings added finer-grained detail. In the anterior-posterior direction, the practitioners showed lower sample entropy and lower mean power frequency, both indicating that their sway was smoother and less erratic. Sample entropy quantifies the unpredictability of a signal; a lower value means the trajectory is more regular and controlled. Mean power frequency reflects how fast the center of pressure oscillates, so a reduction suggests slower, more deliberate adjustments rather than rapid, reactive jerks.

Frequency-domain analysis sharpened this picture further. When postural demands increased, the Tai Chi group exhibited greater energy in low-frequency bands and reduced energy in mid-frequency bands compared with controls. In postural research, low-frequency sway is often associated with slow, strategic weight shifts driven by anticipatory control, while mid-frequency components are linked to faster corrective reflexes. The practitioners’ profile therefore points to a postural strategy that relies less on last-second rescue maneuvers and more on continuous, graceful regulation. As the authors conclude, long-term Tai Chi practitioners demonstrated greater cortical regulation in postural control, characterized by smoother and less abrupt postural adjustments and a reduced reliance on rapid corrective responses when stability was challenged.

Several caveats frame the significance of these findings. The study was cross-sectional, comparing existing practitioners with non-practitioners rather than randomly assigning novices to training, so it cannot fully rule out the possibility that people with naturally superior balance and brain organization are more drawn to Tai Chi in the first place. The sample sizes, while adequate for the mixed-model statistical analysis the researchers employed, were modest, and the participants were healthy older adults rather than frail individuals at high risk of falling. Longitudinal trials will be needed to confirm that Tai Chi training itself drives the cortical adaptations observed here. Nevertheless, the convergence of evidence, from clinical balance scores to hemodynamic brain imaging to the physics of sway, forms a coherent and biologically plausible account of how a centuries-old movement practice tunes the modern aging brain.

The implications reach well beyond martial arts studios. Falls among older adults impose enormous medical and personal costs worldwide, and interventions that are safe, low-impact, and engaging are urgently needed. If practicing Tai Chi strengthens the functional connectivity of the sensorimotor network and cultivates a calmer, more anticipatory postural style, it offers a rare combination of accessibility and mechanistic depth. The study also highlights the value of portable neuroimaging tools like fNIRS, which allow scientists to watch the brain work during real movement rather than inferring its behavior from static scans. For millions of older adults wondering whether slow, deliberate movement can genuinely change the body’s relationship with gravity, this research provides a measurable answer: in the brains and balance of long-term practitioners, the evidence is written in oxygen, connectivity, and the quiet steadiness of every step.

Subject of Research: Cortical adaptation and postural control in long-term Tai Chi practitioners among older adults

Article Title: Long‑term Tai Chi practice promotes cortical synchronization in postural control among older adults

Article References: Chen, X., Sun, J., Sun, T., Yang, X., Jiang, J., & Niu, W. (2026). Long‑term Tai Chi practice promotes cortical synchronization in postural control among older adults. BMC Complementary Medicine and Therapies. https://doi.org/10.1186/s12906-026-05600-2

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05600-2

Keywords: Tai Chi, postural control, older adults, functional near-infrared spectroscopy, cortical synchronization, functional connectivity, center of pressure, balance, primary motor cortex, somatosensory cortex, fall prevention, neurophysiology