you are right to think that consciousness requires a linking between one to another and if a third person is unreachable we define them as unconscious even if there consciousness is occupied with some doing or thought. and all of our consciousnesses fall apart and break down leaving our karma-inertia(doubly stated and bodged term here) to defend our"selfs", or rather what is left. and then we take on a liking to a path towards a birth(called 'becoming' often in Buddhist literature) and then become born into the faculties of that 'life'. e, and this whole process is like driving in a circle at a point. and a term "stream-entry" denotes a person who is on the right path to get out of the said circle.