The electrofluidic brain as a basement layer for neural computation

This article reappraises brain function by reconsidering the role of cerebral fluid dynamics in cognition. Tracing a lineage from early modern thinkers like Descartes-who invoked hydraulic metaphors and 'animal spirits'-to J.C. Bose's pioneering studies on electro-mechanical plant physiology, and culminating in contemporary findings on cerebrospinal fluid (CSF), extracellular space (ECS), and neurovascular coupling, we reveal a forgotten yet vital computational substrate. We argue that alongside the well-studied digital operations of neural circuits exists a slower, analog, evolutionarily older layer of electrofluidic computation. This system-comprised of ionic diffusion, convective CSF flow, and vascular modulation-not only supports but dynamically shapes neural activity. The brain emerges as an electromechanical ecology of electric pulses and fluid flows, where the mind is both a pattern of neural activity and a choreography of fluid flows.