Measuring Neural Health: An Energetic Signature of the Living Brain

Quantifying neural health before irreversible decline occurs remains one of the central challenges in neuroscience and medicine. Across epilepsy, psychiatric illness, neurodevelopmental disorders, and neurodegeneration, we lack a unifying physiological standard that defines what a "healthy brain" truly is - and how it begins to fail. In this talk, I will introduce the Brain Entropy Index (BEI), a physics-grounded biomarker built on two organizing principles of living neural systems: entropy maximization in spatial energy distributions and tight homeostatic regulation of neural activity. In a healthy resting brain, energy is broadly and efficiently distributed across regions, reflecting high entropy, while remaining remarkably stable and tightly controlled. BEI operationalizes neural health through five measurable energetic properties: lognormal energy distributions, balanced regional allocation, statistical independence between regions, low variance, and temporal stability. I will present results from multimodal EEG, fMRI, and MEG datasets comprising over 525 participants across neurological, psychiatric, neurodevelopmental, and neurodegenerative conditions. BEI not only differentiates healthy and clinical populations, but scales with disease severity and generalizes across diagnostic categories and imaging modalities. These findings suggest the existence of a disease-agnostic, modality-invariant energetic signature of neural health. By reframing brain function through the lens of energetic organization, BEI provides a quantitative foundation for early detection, patient stratification, and real-time monitoring of therapeutic response.