Why not proceed by process of deduction? We probably don't need the medulla oblongata. The cerebellum might be unnecessary. Huge swaths of the cerebral cortex may be unnecessary. See if sentience remains.

Sounds cruel, of course. Selective amputations have been done on non-human animals, and they tell us a lot.

it seems we do need the medulla. If you take that out, the person will be in a coma. The problem with your suggestion is that many brainstem regions, such as the medulla, are interpreted as activating cortex and thalamus in a way that cannot be replicated through other means. So the question of what precisely is required for consciousness is complicated by the fact that we do not know at what point in the causal chain or process that consciousness is associated with or produced.

What about certain basal ganglia? Don't those get nuked in parkinson's people? They are still sentient. Any neuro guys here?

there are at least a couple

even Parkinson's patients in advanced stages present with cognitive disturbances so you can't rule out a basal ganglia contribution to consciousness.

I think as long a cybert is removing body parts he should find the same doctor who clipped his nuts to remove the brain parts he is suggesting have no value, and then return to speak of what is necessary and not.

Having a hard time believing his story in the first place it would at least be entertaining to have him speak of having parts of his brain removed along with his reproductive organs.
I think having his reproductive organs removed is an indication that parts of his brain aren't necessarily functioning to their full capacity anyway which by some strange standard may lead to the idea of removing what isn't necessary..???

I am quite sentient still.

It's all subject to relativity dontcha think?

Many thanks to whoever deleted my post!!