The thing with those tanks is that it’s effortless to do a sanity check and receive immediate input anytime you like. You can touch the tank, lift the lid, etc.

Your point still stands of course.

My naive guess is that, although very jarring at first, most people would actually get used to it in not too long of a time. Humans adapt easily. Also, if they can achieve that feat, they could probably also trick the brain into feeling like it has robotic or virtual body parts.

Maybe people with locked-in syndrome could provide some reports of what it's like. It's not the exact same, but it may be similar.

> most people would actually get used to it

All evidence we have regarding long stays in solitary confinement or sensory deprivation indicates everyone trends towards psychosis.

For sure. I was assuming a hypothetical ultra-futuristic scenario where the vat brains could communicate with each other via some mechanism, and could access the Internet and consume media and such. Basically you could be just as social as any homebody; just without the body. And maybe they could do some kind of VR body projection thing that mimics all the physical senses. Solitude is a separate matter.

Even in a float tank you still have some sensory input, especially when you drift over and collide with the tank walls.