Richard Avenarius’ Oscillations and the Neural Code: From Historical Insights to Future Neuroscience

Neural oscillations play a key role in modern neuroscience, linking perception and cognition through rhythmic coordination across distributed networks. Yet the conceptual roots of oscillatory theory trace back long ago. Between 1888 and 1890, Richard Avenarius depicted brain equilibrium as a rhythmic alternation between disturbance and restoration, anticipating the later discovery of EEG and several core concepts of modern neurodynamics. We reinterpret Avenarius’ concept of oscillatory equilibrium and his qualitative vocabulary through the framework of contemporary neural coding theories, encompassing rate, temporal, phase, population, predictive, correlation-based coding, etc. Avenarius’ cyclical sequences of excitation and compensation evoke the homeodynamic and error-corrective processes that govern energy minimization, while his account of oscillatory repetition, synchrony and contrast resonates with modern notions of synaptic adaptation, phase coherence, cross-frequency coupling, attentional modulation, predictive updating within hierarchical neural models. Avenarius’ framework provides also a basis for formulating testable hypotheses about yet unexplored principles of the neural code. From his conception of oscillatory equilibrium arise theoretical possibilities like metabolic–oscillatory coupling, where energy flux and neural rhythms jointly encode information; topological coding, where transient network geometries convey meaning; anti-phase coding, where contrast arises from oscillatory opposition; homeodynamic coding, where informational value lies in the trajectory toward equilibrium; habituation trajectory coding; affective coding; silent coding, etc. Unlike conventional historical analyses that regard philosophical physiology as outdated, we reinterpret it as a theoretical precursor to computational neuroscience, framing Avenarius’ model as a conceptual architecture that unites energy regulation, oscillatory synchronization and informational stability within a coherent dynamic framework.