Evolving sentience (based on a lecture at the Animal Consciousness Conference, Dharamshala, India, May 2023)

The lecturer puts forward a thesis according to which an evolutionist approach to consciousness can solve its “hard problem” with radical implications for understanding of animal sentience. Taking off from his discovery of blindsight – insentient vision – after removal of the visual cortex in a monkey, named Helen, Humphrey argues that “phenomenal consciousness” is a relatively late evolutionary innovation, that may be restricted to mammals and birds;and that another form of consciousness, “cognitive consciousness”, evolved much earlier and is much more widespread in the animal kingdom. In this lecture, Humphrey for the first time introduces his division of all animals into three classes: 1) “unconscious”, for example, worms, jellyfish; 2) “cognitively conscious, but not sentient”, for example, bees, octopuses; 3) “cognitively conscious and sentient”, for example, parrots, dogs and people. Humphrey suggests that many non-sentient animals may have consciousness in a robotic, zombie-like form: it regulates the work of the brain, resolves possible conflicts, and gives coherence and direction to thoughts and actions. Returning to films made fifty years ago of Helen’s visually-guided behaviour, Humphrey recently observed what he now believes was indeed zombie-like conscious awareness: although Helen had blindsight, she hesitated before deciding on the basis of vision which path to follow, as if consciously “considering the options”.