Aging and invariability
Of course one should not forget how stable we ourselves feel, also we grow older over years and still think we remain the same person throughout these years, so the brain does not seem to change that much.
Anesthesia and consciousness
General anesthesia itself is also an interesting state, as it defines what consciousness is not. We know that in this state there is no consciousness, however the brain still works, and especially sensory 'processing' still takes place, it just is not conscious or can exert any effect on behavior, because there is no behavior druing general anesthesia.
What is cross modal-plasticity? Is it possible?