Sean Carroll on his podcast interviewed Lisa Aziz-Zadeh on embodied cognition:
Brains are important things; they’re where thinking happens. Or are they? The theory of “embodied cognition” posits that it’s better to think of thinking as something that takes place in the body as a whole, not just in the cells of the brain. In some sense this is trivially true; our brains interact with the rest of our bodies, taking in signals and giving back instructions. But it seems bold to situate important elements of cognition itself in the actual non-brain parts of the body. Lisa Aziz-Zadeh is a psychologist and neuroscientist who uses imaging technologies to study how different parts of the brain and body are involved in different cognitive tasks.
As Carroll notes in his description, the idea of embodied cognition could almost be considered trivially true. The body is the brain’s chief object of interest. It is hardwired to monitor and control it. Cognition in a brain is relentlessly oriented toward this relationship, to the extent that when we think about abstract things, we typically do so in metaphors using sensory or action experience, experiences of a primate body.
A recent study showed that our memories and imagination are actually mapped according to internal location maps primordially used for tracking physical locations. In light of the brain’s body focus and orientation, this makes complete sense. (I often think of the location of various web sites, including this one, as existing in an overall physical space, which completely fits with these findings.)
It’s fair to say that the body is what gives the information processing that happens in a brain its meaning. That said, I do think some of the embodied cognition advocates get a little carried away, asserting that thinking is impossible without a body.
It may be that a human consciousness can’t develop without a body. If we could somehow grow a human brain without a body, it’s hard to imagine what kind of consciousness might be able to form. It seems like it would be an utterly desolate one by our standards. But once it has developed with a body, I think we have plenty of evidence that the human mind is far more resilient than many people assume.
Patients with their spinal cord severed at the neck are cut off from most of their body. Without the interoceptive feedback, their emotions are reportedly less intense than healthy people’s, but they retain their mind and consciousness. Likewise, someone can be blind, deaf, lose their sense of smell, or apparently even have their vagus nerve cut, and still be conscious (albeit perhaps on life support).
It seems like the only essential component that must be present for a mind is a working brain, and not even the entire brain. Someone can have their cerebellum destroyed and remain mentally complete. (They’ll be clumsy, but their mind will be intact.) The necessary and sufficient components appear to be the brainstem and overall cerebrum. (We can lose small parts of the cortex and still retain most of our awareness, although each loss in these regions comes with a cost to our mental abilities.)
Embodied cognition is also sometimes invoked to make the case that mind uploading is impossible, even in principle. I think it does make the case that a copied human mind would need a body, even if a virtual one. And it definitely further illuminates just how difficult such an endeavor would be. But “impossible” is a very strong word, and I don’t think this line of reason really establishes it.
Unless of course I’m missing something?