Many people have experienced a feeling of “zoning out” on long car drives, where they seem to drive for some time without realizing that they are driving. In some ways it feels as though the time in which you were driving while “zoned out” simply didn’t happen, as if you were unconscious.
There are three proposals as to what might be happening during these episodes: that the driving is being done by the unconscious mind, that you are conscious during this time but simply not forming memories, and that higher introspective consciousness is absent while perceptual consciousness is still present. The only one of these possibilities that I find implausible is that perceptual consciousness remains while introspective consciousness is absent (unless we construe it as simply another way of saying that memories aren’t being formed). It would seem that if we accept this suggestion, which is supported by arguments to the effect that we couldn’t drive without some consciousness of the road, it would seem necessary to grant perceptual consciousness to robot cars as well (cars that can drive themselves). Clearly robot cars aren’t conscious, and so if they can drive without consciousness so can we, in principle. Of course we could argue that the notion of consciousness that my judgments concerning robot cars rests on is that of introspective consciousness. This may be so, but to extend perceptual consciousness to simple automations is at best to misuse the word consciousness, and would make our understanding of introspective consciousness suspect as well.
As for the other two possibilities, that we drive unconsciously, or that we aren’t forming memories during that time, what is interesting about them is that we have no way of subjectively determining which is which. But consciousness is a subjective notion (by which I mean that the best judge of whether some is conscious is the person themselves), and so I would argue that these possibilities are essentially the same, that a period in which memories aren’t forming is simply a way of being unconscious. This plays into my theory, proposed previously, that a moment is conscious not only because of properties present at that moment but also because of how it is part of a temporally extended conscious system. Moments in which memories aren’t forming then can’t be considered conscious because they aren’t properly integrated into subsequent mental states.
Of course this raises the tricky question of how to think about times that we used to remember but simply have forgotten about. Our initial response might be to argue that somehow even those forgotten memories are integrated with us, but a much better solution is to abandon our naïve intuition to take a person’s entire life as a single conscious system. If we instead consider smaller increments, such as periods of continual consciousness, the problem disappears. It is true that you might forget the events of the morning (although most people can recall them in most situations), but even so they still have a distinctive causal effect on your mental states for the remainder of the day. We can’t make that argument for memories forgotten over the course of a lifetime, however, because the causal effects of a specific forgotten mental state have probably been overshadowed by the effects of the many many other mental states the system has been in, and thus it is hard to say how they could be considered to have a causal connection to the mind many years later. In fact we might even want to consider breaking up the day into multiple overlapping conscious systems, but that suggestion is getting far ahead of ourselves, so just consider it idle speculation for the moment.
Another possible problem is as follows: instead of “zoning out” as described here the person on the road continues to be conscious as normal, but when they snap back to reality all the memories of that time are lost (it has no causal effect upon them). This isn’t an actual possibility for what happens when people zone out on the road, but it is still something that we should consider. What should we say about this case? From the viewpoint of the person after “snapping back” those experiences aren’t conscious, since they aren’t part of their conscious system, but they are part of a different conscious system, so in that sense they are conscious, just conscious to a view point which the person after the fact has no knowledge of. The question this raises then is what right do we have to say that our supposedly “unconscious” mental activities are not part of some different conscious system? Surely this sounds strange, but what reason do we have for rejecting it? The answer leans on the fact that while our brains are complex they are not infinitely so. The way in which states are connected to each other over time allows some behaviors, such as language and reasoned deliberation, to arise. However, when people are unconscious they fail to display these complex behaviors (not even behaviors complex as those displayed by simple animals, such as solving puzzles). In some cases, for example in akinetic mutism, where patients are by all standards awake, but at the same time lacking consciousness. Now it is true that such behaviors could be displayed by unconscious systems (which is why the Turing test doesn’t infallibly detect consciousness), but such unconscious systems must be vastly more complex to act just like a conscious system without being conscious, more complex than our actual brains are. And so since we don’t display the abilities that our consciousness allows us to have during episodes of supposed unconsciousness we can safely say that they aren’t parts of some other conscious system.