The search for invertebrate consciousness

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.

Automated summary

There is no consensus on the consciousness of invertebrates and the methodology to resolve this issue. Three broad approaches, theory-heavy, theory-neutral, and theory-light, are distinguished. The theory-heavy and theory-neutral approaches face problems, leading to the suggestion of a middle path, the theory-light approach. At the core of this approach is the hypothesis that consciously perceiving a stimulus enhances certain cognitive abilities compared to unconscious perception. This facilitation hypothesis can guide the study of invertebrate consciousness. A systematic search for consciousness-linked cognitive abilities, their interrelationships, and their sensitivity to masking is needed.