There are many different theories of consciousness and I have discussed these before in connection with Asa H and AI in general. I still believe that there is something to a number of these different theories. I just want to add an additional observation from my work with Asa H.
As Asa receives a stream of input it may identify one or more cases (categories or patterns or sequences) in its case memories that closely match this stream (so far at least). Any actions that will be triggered are predictions taken from these remembered cases. In order to reduce search (when one is considering a large, complex case base memory) I sometimes stick with the same active case(s) so long as the degree of match with new input does not degrade too much. (i.e., I don't do a search through all of the case memory every time a small new amount of input appears.) The cases which are present in the memory but which are not active and not being searched through at that moment might be considered to be in Asa's "unconscious." The case(s) that are active, that Asa is following at this moment, might be considered to be what Asa is "conscious" of. Typically the amount of memory that Asa is conscious of is much smaller than what Asa is unconscious of. Consciousness here results from the need to reduce search/computational complexity. Any actions that are triggered come from the conscious case(s).
We might choose to keep a maximum of 7-9 cases active. (But at how many levels in the hierarchy?) The unconscious cases are in a long term memory. The conscious cases are held active short term. Substantial thought (the Asa extrapolation routine for example) is running subconsciously (and is creative).