> You're right - I mixed up cerebellum/cerebrum/cortex terminology. My bad. The cases I'm referencing are hydrocephalus patients with severely compressed cerebral tissue who maintained normal cognitive function. The point about structural variation not precluding consciousness stands.

Hmm, I don't think it would be dogmatic to call hydrocephalus-induced changes 'structural variation.' Structural variation would be the thickness of subcortical bands or something like that - something where if you take 100 people, you'll see some sort of canonical distribution around a population mean.

Instead, you're describing a disease-induced change (structural yes, but not variation but instead pathology).

We're now in a different regime; we don't expect just any disease to reduce consciousness, so it stands to reason that hydrocephalus would not necessarily reduce consciousness.