We need to explain subjective experience, but its explanation may not be mechanistic

Integrated information theory (IIT) aims to explain consciousness by linking its subjective structure to physical systems without reducing it to neural activity alone. This article identifies ambiguities in IIT, particularly tensions between its claim that experience is ontologically and epistemologically primary and its goal of explaining consciousness in physical, operational terms. The authors propose ways to resolve these issues and suggest alternative explanatory approaches—mathematical, processual, and autonomy-based—that may better guide future models of consciousness. The goal is to clarify points of contention for both supporters and critics of IIT.

Study at a glance

Abstract

Models of consciousness need to explain both the objective correlates of conscious experience as well as its subjective structure. However, such an explanation would not need to entail a reduction exclusively in terms of physical or neural systems. A model that intends to avoid such reduction is integrated information theory (IIT). In this article, we discuss the explanatory rationale of IIT, its potential inconsistencies and its consequences for the neuroscience of consciousness more broadly. In particular, we identify ambiguities regarding the directionality of the explanation, i.e. important tensions between IIT's purported ontological and epistemological primacy of experience, and its explanatory aim of accounting for consciousness in physical, operational terms. Across the text, we propose several ways to avoid these issues and eventually complement, enhance or replace the model. The main goal is to motivate clarification among IIT-proponents and inform IIT-opponents on accurate points of contention, without thereby misrepresenting the model. In our final section, we introduce alternative explanatory paths: mathematical, processual, and autonomy-based types of explanations. These novel and sound explanatory strategies may better inspire the next generation of models of consciousness.