A modified concept of self-consciousness is presented that merges essential features from two contrasting theories. The model proposes that self-consciousness emerges from the brain's comparative representation of sensations originating in the subject's own body versus those from the environment. This comparison is argued to be both essential and sufficient for self-consciousness, unlike alternative proposals. The model also describes a gradual, overlapping progression of sensory and cognitive abilities across evolution and development, rather than distinct, discrete stages of consciousness.
Self-consciousness in biological organisms depends on an individual's ability to distinguish sensory input from its environment from input arising from its own body, a process grounded in embodiment. Artificial systems, by contrast, lack this embodied distinction because software processes input but does not substitute for a body. To replicate biological self-consciousness, an artificial system would need hardware with a comprehensive sensorium integrated throughout its material, software that can separate bodily from environmental signals, bidirectional communication between hardware and software, and the capacity to integrate bodily signals into a unified sense of self. Meeting these requirements in non-living material is considered unlikely.