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bioRxiv · 10.1101/2024.04.12.589163

From micro to macro units: a mathematical framework for identifying the causal grain of a system from its intrinsic perspective

Marshall, W.·Findlay, G.·Albantakis, L.·Tononi, G.
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Abstract

Integrated information theory (IIT) aims to account for the quality and quantity of consciousness in physical terms. According to IIT, a substrate of consciousness must be a system of units that is a maximum of intrinsic, irreducible cause-effect power, quantified by integrated information ({varphi}s). Moreover, the grain of each unit must be the one-- from micro (finer) to macro (coarser)--that maximizes the systems intrinsic irreducibility (i.e., maximizes{varphi} s). The units that maximize{varphi} s are called the intrinsic units of the system. This work extends the mathematical framework of IIT 4.0 to assess cause-effect power at different grains and thereby determine a systems intrinsic units. Using simple, simulated systems, we show that the cause-effect power of a system of macro units can be higher than the cause-effect power of the corresponding micro units. Two examples highlight specific kinds of macro units, and how each kind can increase cause-effect power. The implications of the framework are discussed in the broader context of IIT, including how it provides a foundation for tests and inferences about consciousness.

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Marshall, W., Findlay, G., Albantakis, L., Tononi, G.. 2024-04-15. From micro to macro units: a mathematical framework for identifying the causal grain of a system from its intrinsic perspective. https://doi.org/10.1101/2024.04.12.589163

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