[KingMob]

Former consciousness neuroscientist here. There's some great explanatory abilities about IIT and Tononi's phi measure, but it's not clear it's sufficient.

On the upside, it explains why the cerebellum, despite comprising half the neurons of the brain, has virtually no impact on awareness when removed (like for tumors or epilepsy). The IIT answer is that the cerebellum is highly regular, like a GPU having many units, but all doing the same thing. In this sense, it has lower phi than the cerebrum, which is way more heterogeneously organized. This might also explain why awareness is lost in deep sleep or epileptic seizures; the theory is that the electrical pattern becomes much simpler, and lower phi.

The downside is that it's not clear where the dividing line between conscious/unconscious should be. A planarian only has ~8k neurons; is its phi sufficient for consciousness, or is it a biological robot? Or put it the other way: the phi of things like the internet or a biosphere could be quite high, but are they conscious?

As my advisor liked to joke, "What's the phi of the population of China?"

[visarga]

> "What's the phi of the population of China?"

Small, because if you cut it in 100, you still get 100 functioning parts. Can't cut the brain in 100 and still get functioning mini-brains.

[KingMob]

Ah, but phi measures integration levels, not independent survivability. The cause-effect structures are reduced by 99% in your scenario. The joke (and implied criticism) is that society itself (not the individual members) might have a high enough phi to pass some "consciousness threshold", and if we think that's absurd, it should cause us to question IIT.

Don't get me wrong, IIT is one of the best mathematical models of consciousness out there, but I don't think it's the final word in the matter.

[21]

> The IIT answer is that the cerebellum is highly regular, like a GPU having many units, but all doing the same thing.

Isn't the cortex also the same unit (the cortical column) repeated over and over again?

[KingMob]

Not at all. I wouldn't even argue that the cortical column is the main organizational unit.