Consciousness and integrated energy differences in the brain

Abstract

To understand consciousness within the framework of natural science we must acknowledge the role of energy in the brain. Many contemporary neuroscientists regard the brain as an information processor. However, evidence from brain imaging experiments demonstrates that the brain is actually a voracious consumer of energy, and that functionality is intimately tied to metabolism. Maintaining a critical level of energy in the brain is required to sustain consciousness, and the organisation of this energy distinguishes conscious from unconscious states. Meanwhile, contemporary physicists often regard energy as an abstract mathematical property. But this view neglects energy's causal efficacy and actuality, as identified by Aristotle and later appreciated by many important biologists, psychologists and physicists. By reconsidering the nature of energy and recasting its role in neural activity, we arrive at a theory of consciousness that is consistent with the laws of physics, chemistry and biology. The argument draws on the integrated information theory (IIT) developed by Tononi et al. but reinterprets their findings from the perspective of energy exchange. In IIT, the conscious state in a system, such as a brain, is defined by the quantity of integrated differences, or information, it contains. According to the approach outlined here, it is in the nature of energy to manifest differences of motion and tension. The level of complexity of the energy differences in a system determines its conscious state. Consciousness occurs because, in Nagel's terminology, there is 'something it is like' to be a sufficiently complex state of energy differences.