Abstract

The physical basis of conscious experience is revealed by direct observation and analysis of any conscious experience. Human conscious experience has an invariant structural mode of organization based on the three types of space-time intervals (light-like, time-like, space-like). Sensory input activates the autonomic nervous system, endocrine system, and ascending reticular activating system to produce the awake conscious state. The dorsal and ventral frontoparietal attention networks are activated. Dorsal and ventral cortical functional streams carry “what”, “where”, and “when” information to the medial temporal lobe for the encoding, storage, and recall of conscious experience (episodic memory). Hippocampal place cells and time cells encode events in space and time within spatiotemporal contexts conveyed by entorhinal cortex grid cells and ramping cells. Theta phase precession unifies the encoding of space and time in the hippocampus so that segments of space and time are encoded in the hippocampus. Theta travelling waves ensure that the instantaneous output of the hippocampus consists of topographically-organized segments of space and time, space-time intervals. By parsing spatiotemporal contexts into quantal units of where and when events occur (spacetime intervals), hippocampal neurons bridge, and thereby organize events, in a conceptual organization of events (conscious experience). Space-time intervals are extracted from the hippocampus by a prefrontal cortex-basal ganglia-thalamic-prefrontal cortex loop for the cognitive, affective, and motivational aspects of conscious experience.