A new theory on consciousness is presented. According to our neuroscientific model, focal awareness is the result of neurophysiological patterns of voluntary or involuntary information, registration, storage and retrieval performed in accordance with organismic biphasal homeostatic rules and regulations that follow the demand-supply principle. The information-processing operation consists of three major elements: 1. Involuntary activated 'inherited schematic representation' (ISR) programs that monitor homeostatic negative feedback programs and remain inert during the storage period; 2. Voluntary activated 'acquired engram linkage' (AEL) programs that monitor the preferential self-efforts designed to maintain homeostasis and dynamic adaptational survival; this information remains fixed in the storage reservoir; and 3. Outer, nonselective sources of activation that derive from the assembly of the sensory information system. Consciousness is limited by the microneurostructural boundaries of 'conscious instrument panel' (CIP) needed to handle this unique biological experience. At any unit of time, the conscious subjectively identifies states of pleasure (first phase of homeostasis maintenance) or displeasure (second phase of homeostasis) which are associated with the alarm subsystem of the 'organismic defense system' (ODS). Thus, consciousness is a form of neurophysiological activity that excludes unconscious existence in order to monitor information. This model promotes our understanding of the biological essences of consciousness. (C) 2000 Harcourt Publishers Ltd.