The Physical Boundary of Conscious and Unconscious Processing: A Circuit-Derivation of the Conditioned Reflex

This paper proceeds from the classical experimental facts discovered by Pavlov in 1904 to independently derive the physical mechanism of the conditioned reflex, and further points out that this mechanism provides a unified theoretical framework for understanding the physical boundary between conscious processing and unconscious automaticity. The sound of the bell enters the dog's ear and is converted into a current that surges along the auditory pathway into a dense node of the brain; the food enters the dog's mouth and is converted into a current that surges along the gustatory pathway into the same dense node. The two currents pour in closely adjacent in time; the behavior of the dielectric at the intersection is equivalent to being broken down, and the two originally independent low-resistance pathways are welded, at the functional-topological level, into a single short circuit. Thereafter, with the injection of the bell alone, charge is compulsorily directed along the short-circuit pathway to the salivation branch. This short-circuit formation is the physical image of the transition from conscious pairing to unconscious automation. Extinction, at the functional-topological level, manifests as the gradual pruning of the short-circuit pathway within the maintenance window, a process that requires conscious processing of the mismatch to generate the error current that marks the pathway for pruning. The entire derivation relies on no external theoretical framework; it is independently completed solely from the physical principle that current selects the path of least impedance and the nine core experimental facts rigorously verified by Pavlov and Skinner a century ago. This paper further demonstrates that the short-circuit mechanism possesses precise, independently verified biological correspondences in the nervous system. The framework suggests a physical definition: conscious processing corresponds to error-driven current correction on high-resistance pathways, while unconscious automaticity corresponds to the effortless conduction of current along welded low-resistance short circuits. The short-circuit mechanism independently derived in this paper is fully consistent with the same physical process rigorously demonstrated within a larger framework by Yu (2026b).