Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2020 Oct;24(10):789-801.
doi: 10.1016/j.tics.2020.07.007. Epub 2020 Aug 20.

Dimensions of Animal Consciousness

Jonathan Birch  1 , Alexandra K Schnell  2 , Nicola S Clayton  2
Affiliations
Review

Dimensions of Animal Consciousness

Jonathan Birch et al. Trends Cogn Sci. 2020 Oct.

Abstract

How does consciousness vary across the animal kingdom? Are some animals 'more conscious' than others? This article presents a multidimensional framework for understanding interspecies variation in states of consciousness. The framework distinguishes five key dimensions of variation: perceptual richness, evaluative richness, integration at a time, integration across time, and self-consciousness. For each dimension, existing experiments that bear on it are reviewed and future experiments are suggested. By assessing a given species against each dimension, we can construct a consciousness profile for that species. On this framework, there is no single scale along which species can be ranked as more or less conscious. Rather, each species has its own distinctive consciousness profile.

Keywords: animal consciousness; animal sentience; cephalopods; corvids; dimensions of consciousness; levels of consciousness.

PubMed Disclaimer

Figures

Figure I
Figure I. Two Corvid Species Commonly Used in Comparative Cognition Research.
(A) Ravens © User: Colin/ Wikimedia Commons/CC BY-SA 4.0; (B) Eurasian jay © Mrs Airwolfhound/Flickr/CC BY-ND 2.0.
Figure I
Figure I. Two Cephalopod Groups That Are Suitable Candidates for Investigating Consciousness.
(A) Octopus © dynamofoto, used under license; (B) cuttlefish © Alexandra Schnell.
Figure 1
Figure 1
Key Figure Hypothetical Consciousness Profiles for Elephants, Corvids, and Cephalopods These hypothetical profiles highlight six important dimensions of variation, with p-richness represented separately forvision and touch. These are not finished, evidence-based profiles: they are conjectures based on current evidence. A key goal for animal consciousness research should be to produce a much richer evidence base for the construction of consciousness profiles and more precise ways of measuring the dimensions. Abbreviations: p-richness, perceptual richness; e-richness, evaluative richness.
See this image and copyright information in PMC

References

    1. Hamad S. Animal sentience: the other minds problem. Anim Sent. 2016;2016:1.
    1. Boly M, et al. Consciousness in humans and non human animals: recent advances and future directions. Front Psychol. 2013;4:625. - PMC - PubMed
    1. Key B. Why fish do not feel pain. Anim Sent. 2016;3:1.
    1. Woodruff ML. Consciousness in teleosts: there is something it feels like to be a fish. Anim Sent. 2017;13:1.
    1. Barron AB, Klein C. What insects can tell us about the origins of consciousness. Proc Natl Acad Sci U S A. 2016;113:4900–4908. - PMC - PubMed

Publication types