Full Idea
The conscious 'dynamic core' of the brain can maintain its unity over time even if its composition may be constantly changing, which is the signature of a process as opposed to a thing.
Gist of Idea
Consciousness is a process, not a thing, as it maintains unity as its composition changes
Source
G Edelman / G Tononi (Consciousness: matter becomes imagination [2000], Ch.12)
Book Reference
Edelman,G/Tononi,G: 'Consciousness: how matter becomes imagination' [Penguin 2000], p.152
A Reaction
This is the functionalists' claim that the mind is 'multiply realisable', since different neurons can maintain the same process. 'Process' strikes me as a much better word than 'function'. These theories capture passive mental life better than active.