System, subsystem, hive: boundary problems in computational theories of consciousness

A computational measure of consciousness (MoC) must be graded, applicable across systems and times, but faces a boundary problem: any MoC that labels a system conscious will also label many of its subsystems, irrelevant extensions, and aggregates of conscious individuals as conscious, implying either that the measured properties are epiphenomenal or that minds proliferate bizarrely. The authors propose solving this by requiring MoCs to measure intrinsic or systemic properties—those that distinguish systems whose existence is a matter of fact from those existing only by interpretation. They argue that a systemic MoC resolves boundary issues and analyze Integrated Information Theory and Geometric Theory of consciousness as test cases.

Study at a glance

Abstract

A computational theory of consciousness should include a quantitative measure of consciousness, or MoC, that (i) would reveal to what extent a given system is conscious, (ii) would make it possible to compare not only different systems, but also the same system at different times, and (iii) would be graded, because so is consciousness. However, unless its design is properly constrained, such an MoC gives rise to what we call the boundary problem: an MoC that labels a system as conscious will do so for some – perhaps most – of its subsystems, as well as for irrelevantly extended systems (e.g., the original system augmented with physical appendages that contribute nothing to the properties supposedly supporting consciousness), and for aggregates of individually conscious systems (e.g., groups of people). This problem suggests that the properties that are being measured are epiphenomenal to consciousness, or else it implies a bizarre proliferation of minds. We propose that a solution to the boundary problem can be found by identifying properties that are intrinsic or systemic: properties that clearly differentiate between systems whose existence is a matter of fact, as opposed to those whose existence is a matter of interpretation (in the eye of the beholder). We argue that if a putative MoC can be shown to be systemic, this ipso facto resolves any associated boundary issues. As test cases, we analyze two recent theories of consciousness in light of our definitions: the Integrated Information Theory and the Geometric Theory of consciousness.