Lability as a Condition for the Urgency and Coordination of Nervous Acts (English Translation of the 1936 Classic)

In his seminal 1936 work, Academician Alexei A. Ukhtomsky provides a rigorous critique of the narrow localizationist views held by classical neurophysiology regarding the static structure of "nervous centers." Developing N. E. Wedensky's fundamental doctrine of physiological lability (the functional mobility of an excitable substrate), the author demonstrates that the central governing apparatus of any physiological function is not a rigid topographic locus, but a dynamic "working constellation" of anatomically dispersed centers united by temporal synchrony and congruent functional rates. Through an in-depth analysis of the speech function and the functional hierarchy of the central nervous system, Ukhtomsky demonstrates that the recruitment of neural ensembles into a unified functional system is governed by their capacity to shift their intrinsic lability and "assimilate rhythm" (attuning to a common operational tempo of impulsion). Ukhtomsky formulates the principle that the functional significance of a given neural center is a dependent variable governed by its current physiological state and the broader context of the prevailing dominant activity. The formation of a dominant (dominanta) is elucidated as a progressive attunement of operational rhythms across heterolabile components of the central nervous system, accompanied by conjugate inhibition of competing reflex arcs and the consolidation of a long-term summation focus (a "cortical scar") that organizes the organism's adaptive responses toward distal environmental demands. Key Experiment and Empirical Prototype: Analysis of the ontogeny and pathophysiology of the speech act (from Broca's motor center and Wernicke's sensory area to subcortical and brainstem mechanisms), complemented by Pflüger's classic "spinal choice" experiment interpreted via progressive shifts in reflex arc lability. Theoretical Model of Dynamic Constellation: Reconceptualization of the "nervous center" from a fixed morphological compartment into a spatio-temporal constellation of centers dynamically coordinated through operational rhythm transformation. Lability as a Dynamic Coordinate: Definition of physiological lability not as a fixed tissue constant, but as a mutable parameter capable of bidirectional shifts (elevation or depression) under the influence of working impulses and humoral factors. Mechanism of Resonance and Conjugate Inhibition: Resolution of temporal dissonance between rapid cortical planning (components of thought) and inert peripheral effectors (components of articulation) via the convergence on a shared "sympathetic rhythm," enforcing simultaneous inhibition of non-aligned neural pathways. Nature of Persistent Dominanta and the "Cortical Scar": Conceptualization of dominant innervation as a sustained intercentral circular process and summation set that preserves neural traces of unresolved problems, governing long-range anticipatory behavior against transient sensory perturbations. Integration with the Theory of the Buteyko Breathing Method (DVBM): Ukhtomsky's principles of lability, functional constellation, and rhythm assimilation provide the primary neurophysiological cornerstone for K. P. Buteyko's theory of the Deliberate Volitional Breathing Method (DVBM). Chronic hyperventilation represents an entrenched pathological cortical-subcortical dominanta characterized by distorted temporal intervals and hyperexcitability of the respiratory center, driving generalized smooth muscle spasm and systemic hypoxia via the Verigo-Bohr effect. The volitional reduction of breathing depth in the Buteyko method constitutes a direct restructuring of the operational lability of the respiratory center: conscious suppression of excessive afferent drives allows the neural substrate to "assimilate a renewed, physiologically balanced rhythm" and restore carbon dioxide homeostasis. In Ukhtomskian terms, breathing normalization shifts the respiratory apparatus into a state of optimal functional stability, rebalances autonomic equilibrium (Kérdö Vegetative Index) toward parasympathetic restoration, and dissolves the deep-seated "pathological scar" of alveolar hyperventilation by establishing a robust, energy-efficient functional constellation.