#206 – Anil Seth on the predictive brain and how to study consciousness

80,000 Hours Podcast

"In that famous example of the dress, half of the people in the world saw [blue and black], half saw [white and gold]. It turns out there’s individual differences in how brains take into account ambient light. Colour is one example where it’s pretty clear that what we experience is a kind of inference: it’s the brain’s best guess about what’s going on in some way out there in the world. And that’s the claim that I’ve taken on board as a general hypothesis for consciousness: that all our perceptual experiences are inferences about something we don’t and cannot have direct access to." —Anil Seth

In today’s episode, host Luisa Rodriguez speaks to Anil Seth — director of the Sussex Centre for Consciousness Science — about how much we can learn about consciousness by studying the brain.

Links to learn more, highlights, and full transcript.

They cover:

• What groundbreaking studies with split-brain patients and blindsight have already taught us about the nature of consciousness.
• Anil’s theory that our perception is a “controlled hallucination” generated by our predictive brains.
• Whether looking for the parts of the brain that correlate with consciousness is the right way to learn about what consciousness is.
• Whether our theories of human consciousness can be applied to nonhuman animals.
• Anil’s thoughts on whether machines could ever be conscious.
• Disagreements and open questions in the field of consciousness studies, and what areas Anil is most excited to explore next.
• And much more.

Chapters:

• Cold open (00:00:00)
• Luisa’s intro (00:01:02)
• The interview begins (00:02:42)
• How expectations and perception affect consciousness (00:03:05)
• How the brain makes sense of the body it’s within (00:21:33)
• Psychedelics and predictive processing (00:32:06)
• Blindsight and visual consciousness (00:36:45)
• Split-brain patients (00:54:56)
• Overflow experiments (01:05:28)
• How much can we learn about consciousness from empirical research? (01:14:23)
• Which parts of the brain are responsible for conscious experiences? (01:27:37)
• Current state and disagreements in the study of consciousness (01:38:36)
• Digital consciousness (01:55:55)
• Consciousness in nonhuman animals (02:18:11)
• What’s next for Anil (02:30:18)
• Luisa’s outro (02:32:46)

Producer: Keiran Harris
Audio engineering: Ben Cordell, Milo McGuire, Simon Monsour, and Dominic Armstrong
Content editing: Luisa Rodriguez, Katy Moore, and Keiran Harris
Transcriptions: Katy Moore