Conventionally consciousness is explained as emerging from electrochemical computational activity of cells in complex neural networks. Prima facie, this is a logical theory as sensory inputs can be de-constructed into data / information—computations are what sorts and processes data—and thus the computational activity of the brain produces phenomenal experiences from sensory data. The only problem is that it is not at all clear how a series of computations can produce phenomenal experience, that aspect of consciousness that is the observer—the experiencer of sensations and mental qualia. Undoubtedly, neuromorphic computations can result in machine learning, and this is most likely an integral aspect of the process of synaptic remodeling (plasticity) that occurs in the brain as one learns.
However, the ability to process data input, execute a response, and optimize that response via some adaptive algorithm is not consciousness. Soft artificial intelligence (AI) can already perform these functions, even replicating the actions/responses of conscious agents, yet there is no reason to believe that the capability to mimic consciousness with adaptive learning implies the system is having an experience. Experience is only possible by an agent possessing consciousness.
The relationship of experience to the nature of information and “objective reality” raises another significant ontological question about whether there can even be existence without experience—without some fundamental phenomenal perception of what is and what is not. If this idea sounds outré, recall that the predominant theory of quantum mechanics, the Copenhagen Interpretation, possesses as one of its basic tenets that elementary particles of nature can only be said to have a definite existence when they are measured, ostensibly by a conscious agent.
This departure from our conventional “common sense” view of the world, as existing firmly and independently of ourselves, is called into question with modern quantum theories that abandons preconceptions of ‘realism’. Even further, unified theories that explain quantum gravity work via a planckian information substratum of spacetime itself, where matter and energy are emergent forms resulting from the expression of information processing occurring at every conceivable loci. What meaning does information have without a system that integrates and experiences it? Would not the entire system—in this case the universe—be the computational engine that produces meaningful data, requiring sentience to be an integral aspect of reality down to the most fundamental level.