The search for invertebrate consciousness.

The debate over whether invertebrates are conscious lacks both agreement and a clear methodology. Three approaches exist: theory-heavy, theory-neutral, and theory-light. Theory-heavy and theory-neutral approaches have serious problems, so the author advocates a middle path: the theory-light approach. This approach relies on a minimal hypothesis: that conscious perception of a stimulus facilitates, relative to unconscious perception, a cluster of cognitive abilities related to that stimulus. This 'facilitation hypothesis' can guide research into invertebrate consciousness. The author argues that what is needed now is not more theory or undirected data gathering, but a systematic search for consciousness-linked cognitive abilities, their relationships, and their sensitivity to masking.

Study at a glance

Abstract

There is no agreement on whether any invertebrates are conscious and no agreement on a methodology that could settle the issue. How can the debate move forward? I distinguish three broad types of approach: theory-heavy, theory-neutral and theory-light. Theory-heavy and theory-neutral approaches face serious problems, motivating a middle path: the theory-light approach. At the core of the theory-light approach is a minimal commitment about the relation between phenomenal consciousness and cognition that is compatible with many specific theories of consciousness: the hypothesis that phenomenally conscious perception of a stimulus facilitates, relative to unconscious perception, a cluster of cognitive abilities in relation to that stimulus. This "facilitation hypothesis" can productively guide inquiry into invertebrate consciousness. What is needed? At this stage, not more theory, and not more undirected data gathering. What is needed is a systematic search for consciousness-linked cognitive abilities, their relationships to each other, and their sensitivity to masking.