They are mostly talking about the cortex, the outer wrinkled layer. Functionally, however, the cortex is completely useless without a whole suite of subcortical structures and actually only has something like 20% of your neurons. Its a part of the whole functional network, not the whole thing, though in mammals it expanded quite a bit and took on a lot of specialization. I dont know if theres such a thing as a 'generic' thalamus network vs 'your' thalamus network, sounds like a question for the connectomics researchers to get on.

A lot of these things A - lie near or on the midline and have much less lateralization and more crosstalk, B - are absolutely vital if you say dont want parkinsonism or to fall into permanent slow wave sleep. Hemispherectomies generally go after the cortex and white matter sometimes taking some of the superficial subcortical stuff, in chunks. The results of such things are usually much more positive in young people of course.

However, since you dont lose autobiographical memories from careful excision of brain parts it does indeed suggest that they're present and distributed throughout...