Can there be a synergistic core emerging in the brain hierarchy to control neural activity by downward causation?

Abstract

The mind-brain relation underlies causal analysis in neuroscience, linked to physical reductionism, information theory, and network science. While the mystery of consciousness is still unresolved, the neurophysiological processes responsible of its emergence from brain dynamics are intensively discussed in contemporary neuroscience. Causation is involved dually there. The first issue is about how neural activity in the brain causally generates conscious experience. The second issue speculates about how consciousness itself could have causal power (free will) to control the brain. Given the emergent and informational nature of consciousness, mental causation could be admissible on the two conditions: downward causation is possible, and information has causal power beyond that provided by matter. Recently, the theory of causal emergence, based on coarse-graining and partial information decomposition, suggested that synergistic information might satisfy the above conditions, thereby reviving the old idea of homunculus capable of controlling the brain. Based on the Causal Equivalence Principle and the definition of multiscale hierarchy, this review shows that assuming these conditions leads inevitably to the double causation fallacy and Cartesian dualism.