A new hypothesis and theory article published in Frontiers in Integrative Neuroscience by Boris Živný of the NeuroCentrum Clinic and SPP Institute in Jesenice, Czechia, proposes a contemporary answer. The paper introduces Persistent Afferent Bias, or PAB, a state-dependent alteration in sensory weighting through which somatic disruption is proposed to influence autonomic regulation. Rather than treating facilitation as a property of a single hyperexcitable segment, Živný reframes it as a network-level phenomenon: neurons remain structurally and functionally intact, but particular afferent streams exert a disproportionate influence on system behavior, altering neural gain, reflex responsiveness, and autonomic output. The construct is positioned as the previously unarticulated neurophysiological mechanism linking altered somatic input to changes in regulatory state within the author’s broader Somato-Psychic Pathway model.

The theoretical foundation rests on a growing recognition in contemporary neuroscience that bias is not merely a byproduct of imperfect processing but a fundamental property of neural systems. Recent evidence indicates that such biases are associated with identifiable neural signatures and organized patterns of processing rather than random distortions, while attentional bias itself appears dynamically regulated and context-dependent. Within this framework, alterations in sensorimotor processing are conceptualized as state-dependent changes in the relative weighting of afferent input within distributed neural networks. Persistent Afferent Bias may arise from multiple sources, including nociceptive input, muscle spindle activity, fascial mechanoreceptor signaling, and viscerosomatic convergence, none of which require localized structural pathology.

Central to the argument is the principle of state-dependent neural regulation. Neuronal responsiveness is shaped not only by structural connectivity but by the system’s current physiological state, reflecting a dynamic integration of autonomic tone, neuromodulatory activity, metabolic and inflammatory signals, and descending regulatory influences. Contemporary predictive processing models, notably those developed by Karl Friston and by Lisa Feldman Barrett and W. Kyle Simmons, describe sensory processing as an actively regulated, predictive process in which the nervous system continuously integrates afferent input with prior expectations to optimize adaptive responses. As a consequence, identical sensory inputs may produce markedly different physiological and behavioral outputs depending on the system’s regulatory state, providing a mechanistic explanation for clinical observations such as variability in tenderness, context-dependent reflex responses, and the rapid reversibility of somatic findings.

Recent empirical work lends support to this broader principle. Studies published in 2025 and 2026 demonstrate that persistent nociceptive input can bias attentional and perceptual processing, leading to preferential weighting of pain-related information, and that attentional bias is dynamically regulated rather than passively distorted. Other findings suggest that perceptual and decision-related representations are continuously shaped by prior states, with past activity reactivated and interacting with ongoing processing in a temporally structured manner, while certain forms of bias may reflect more stable organizational tendencies, such as preferential allocation of processing resources toward self-relevant information. Taken together, these observations suggest that bias is neither a fixed defect nor a transient disturbance but an emergent property of neural systems that is both dynamically regulated and structurally constrained.

Živný organizes the model around a hierarchical regulatory cascade comprising three functionally distinct but related levels. Distorted Proprioceptive Information, or DPI, refers to an alteration in the quality of incoming sensory input, typically arising from disturbances within the somatic system, and represents only one of several potential contributors to Persistent Afferent Bias, alongside persistent nociceptive input, altered muscle spindle activity, visceral afferent signaling, and changes in interoceptive processing. PAB itself represents a state-dependent reorganization of sensory weighting within neural networks. Somato-Psychic Autonomic Dysregulation, or SPAD, reflects a more stable alteration in autonomic regulation that emerges when biased processing becomes functionally embedded within the organism’s regulatory state. Under sustained conditions, SPAD may subsequently give rise to broader functional manifestations, including Somato-Psychic Syndrome, or SPS, a clinical phenotype characterized by emotional, behavioral, cognitive, developmental, and regulatory features such as sleep dysregulation, emotional lability, anxiety features, and attentional instability.

The framework is explicitly positioned as complementary to, rather than competing with, several established bodies of theory. Models of sensorimotor integration and fusimotor control show that muscle spindle sensitivity is dynamically regulated through interactions between alpha and gamma motor systems, supporting the principle that afferent weighting is state-dependent, though these models focus on posture and movement rather than autonomic embedding. Classical somato-autonomic reflex physiology, documented experimentally since the work of Akio Sato and R. F. Schmidt in 1987, demonstrates that somatic stimulation can influence cardiovascular and gastrointestinal function through spinal, brainstem, and supraspinal pathways; PAB extends this perspective by proposing that repeated or sustained afferent influences become progressively incorporated into longer-term regulatory configurations rather than producing only transient responses.

Pain science contributes the concepts of central sensitization and nociplastic pain, which describe increased responsiveness within central nociceptive pathways that can persist beyond immediate tissue injury. The PAB framework builds on these insights but broadens the scope considerably: whereas central sensitization primarily concerns nociceptive systems, Persistent Afferent Bias incorporates proprioceptive, interoceptive, and other afferent channels. Notably, the model emphasizes persistent low-grade and subthreshold nociceptive input that may never reach conscious awareness yet continues to influence autonomic regulation, neural gain, and state-dependent processing over extended periods, since the absence of pain does not imply the absence of ongoing nociceptive signaling. The Neurovisceral Integration model of Julian Thayer and colleagues, which links autonomic flexibility measured through heart rate variability to attention, emotion regulation, and executive function, is likewise treated as complementary, with PAB focusing on the afferent conditions that may give rise to altered autonomic states rather than on their downstream consequences.

Predictive processing and interoceptive inference models, including work by Anil Seth and Friston on active interoceptive inference, describe how neural systems generate and update representations of bodily and environmental states. PAB addresses an earlier stage of the same architecture, examining how sustained alterations in afferent input shape the informational landscape upon which predictive interpretations are constructed. Similarly, the concepts of allostasis and allostatic load, developed by Bruce McEwen and Peter Sterling, explain how organisms adapt to prolonged regulatory demands and how such adaptations can become maladaptive; PAB is proposed as one specific pathway contributing to the regulatory demands that allostatic mechanisms must manage, with persistence as its defining characteristic. The author suggests these adaptations are state-dependent and potentially reversible, persisting only as long as the primary source of afferent bias remains active.

The clinical implications are substantial and, the author argues, directly testable. The model predicts that targeted modification of somatic drivers should produce measurable changes in autonomic markers such as heart rate variability, pupillary dynamics, baroreflex sensitivity, and respiratory variability, even without direct central interventions. It further predicts a characteristic temporal sequence in which changes in autonomic regulation precede observable changes in emotional, behavioral, cognitive, or developmental domains, consistent with the principle of Directional Developmental Sequencing. The framework would be weakened if autonomic changes consistently failed to precede higher-order functional changes, or if modification of presumed somatic drivers showed no relationship to autonomic regulation. The concept emerged from clinical observations in pediatric and adolescent patients treated for Somato-Psychic Syndrome, in whom addressing clinically diagnosable axial somatic disruptions of the postural system was repeatedly followed by changes across higher regulatory domains within clinically relevant time frames. The author acknowledges significant limitations: the Somato-Psychic Pathway is a conceptual framework grounded in established neurophysiological principles rather than a definitive explanatory model, and the proposed relationships linking somatic disruption, PAB, SPAD, and SPS remain to be systematically investigated in longitudinal and experimental settings. The model is explicitly not intended to explain all forms of psychopathology, since genetic, neurodevelopmental, inflammatory, environmental, and psychosocial pathways remain fully compatible and independent. Future research, the paper concludes, will be necessary to determine the prevalence, boundary conditions, physiological signatures, and clinical relevance of Persistent Afferent Bias within broader models of autonomic regulation, neurodevelopment, and mental health.

Subject of Research: A theoretical neuroscience model linking persistent altered afferent input to autonomic dysregulation and higher-order functional manifestations

Article Title: Persistent Afferent Bias: a mechanistic link between somatic disruption and autonomic dysregulation

Article References: Živný, B. (2026). Persistent Afferent Bias: a mechanistic link between somatic disruption and autonomic dysregulation. Frontiers in Integrative Neuroscience, 20, Article 1848233. https://doi.org/10.3389/fnint.2026.1848233

Image Credits: AI Generated

DOI: 10.3389/fnint.2026.1848233

Keywords: Persistent Afferent Bias, autonomic dysregulation, somatic disruption, Somato-Psychic Pathway, central sensitization, predictive processing, allostatic load, proprioception, interoception, heart rate variability, neural gain, facilitated spinal segment