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.

Emergence and Causality in Complex Systems: A Survey of Causal Emergence and Related Quantitative Studies

“…In Figure 2, the black solid lines represent causation without controversy. However, according to a recent paper by Yurchenko [68], the causation represented by the dashed and dotted lines (except the intra-level ones in the meso-level) may not actually be causality but rather reasons or explanations. Yurchenko introduced the term "reason" to distinguish it from the conventional understanding of causality, as cross-level causal effects may not possess causal powers.…”

“…Otherwise, a double causation [67] fallacy may appear. This consistency between causality at different scales is called the causal equivalence principle in Yurchenko's latest article [68].…”

“…Consequently, although the strong emergent properties or processes at the meso-level are supervenient to micro-level properties and interactions, their causes derive from the macro-level and, therefore, second-order patterns or processes. However, there are many debates on the notion of downward causation itself, e.g., [64,68].…”

“…There has been a longstanding debate regarding the ontological and epistemological aspects of causality and emergence throughout history [17,22,68,76]. The authors of [68] highlighted that the concept of "causation" in the literature is often vague and should be differentiated into "cause" and "reason", aligning with ontological and epistemological causality.…”

“…There has been a longstanding debate regarding the ontological and epistemological aspects of causality and emergence throughout history [17,22,68,76]. The authors of [68] highlighted that the concept of "causation" in the literature is often vague and should be differentiated into "cause" and "reason", aligning with ontological and epistemological causality. "Cause" means genuine cause that sufficiently causes the effects (causal closure principle [141] and exclusion principle [142]), whereas "reason" serves as a mere explanation for individuals to comprehend the effects.…”