Waking up from a nightmare, you suddenly realize that what seemed real was in fact a dream. You were inhabiting a world cooked up by the brain, not realizing you were lying in bed. You were comprehensively deluded about your situation.
In what are called lucid dreams, you become aware of the fact that you’re dreaming – you become undeluded. Knowing that you’re dreaming allows you to appreciate something quite remarkable while you are dreaming: that dream reality can be just as vivid and detailed as waking experience. Having had a few lucid dreams myself, I can testify, as have many others, that the dream world seems just as present, tangible and real as what we experience when awake.
Awareness of lucid dreaming is growing, for instance see a recent ABC Nightline report on the phenomenon featuring Stephen LaBerge, a psychologist who offers instruction on how to become lucid while dreaming. One of his clients, Chris Moss, recounted the vividness, the experienced reality of the dream state:
I hope that the [Nightline] segment inspired some folks to give lucid dreaming a try. Even having just one can change your life (I think for much the better). Also, at the end where David Write says regarding my… dream, "a fantasy, not exactly made flesh"...that's the whole point: experientially, it IS made flesh! It's the same flesh here as it is there. It's just that in a normal dream you don't realize that, and in a lucid dream you do!
Should you ever have a lucid dream, you’ll discover what Moss says is true: the brain can construct a vivid virtual world in the absence of any perceptual input. It has the independent neural resources to build a complete, detailed phenomenological analog of reality, including ourselves as actors inside it. Ordinary dreams do this as well to some extent, it’s just that you’re not conscious of the fact. In lucid dreams, you are. Here’s another example, quoted in Metzinger & Windt (original source is Astral Projection by Oliver Fox, 1962):
I dreamed that I was standing on the pavement outside my home. … I was about to enter the house when, on glancing casually at [the pavement] stones, my attention became riveted by a passing strange phenomenon, so extraordinary that I could not believe my eyes—they had seemingly all changed their position in the night, and the long sides were parallel to the curb! Then the solution flashed upon me: though this glorious summer morning seemed as real as real could be, I was dreaming! With the realization of this fact, the quality of the dream changed in a manner very difficult to convey to one who has not had the experience. Instantly, the vividness of life increased a hundred-fold. Never had the sea and sky and trees shone with such glamorous beauty; even the commonplace houses seemed alive and mystically beautiful. Never had I felt so absolutely well, so clear-brained, so inexpressibly free! The sensation was exquisite beyond words; but it lasted only a few minutes and I awoke. (Fox, 1962, p. 32; quoted in LaBerge and Gackenbach 2000, p. 154)
As people learn about lucid dreaming, an interesting fact about the brain will become known: it is a virtual reality generator. But an even more remarkable fact is waiting in the wings: waking experience is virtual reality too.
This seems daft on the face of it. When we’re awake, the world is solid, out there, a 3-dimensional reality with us walking around in it, looking at it, manipulating it. There’s nothing virtual about it. It’s clear that this is real reality, right?
Well, it’s real as reality can get for a brain. As Thomas Metzinger, Antti Revonsuo, Rudolfo Llinas, V.S. Ramachandran and other neuroscientists and philosophers now surmise, consciousness is more or less the same thing when we’re awake as when dreaming. That is, the brain constructs a conscious phenomenal world, with ourselves as part of that world; this is what we experience, or rather is our experience. The difference between waking and dreaming experience is that the former is responsive to perceptual input coming in via the eyes, ears, and other sensory faculties while the latter is not. Both are virtual realities, but one has the crucial property of being constrained, in real time, by the real world outside the head.
Dreams are often crazy and mixed up because they aren’t constrained in this way; they are what the brain does when left to its own devices, the body temporarily paralyzed in bed, all sensory systems shut down. In lucid dreams, because we know we are dreaming, we can choose to fly or walk through walls; we can do just about anything that isn’t logically impossible. But waking experience has to conform, boringly enough, to the requirements of negotiating our external physical and social environment, so our choices are considerably more limited. Hence the attractions of lucid dreaming.
But still, despite what neurophilosophers tell us, it’s likely we will persist in supposing that when we’re awake the world is immediately given to us, that our experience is a direct window on the world, not a world unto itself. That’s how it feels after all, and it isn’t as if we ever wake up from our “dream” of waking experience. So it’s hard to really accept or believe the fact that we as experiencing subjects always inhabit – are actually an element of – a phenomenal world that the brain constructs. But having a lucid dream helps, because you see on a moment-to-moment basis that experience can be, and therefore might always be, a very convincing virtual reality.
The difficulty in realizing the truth of our situation, of becoming undeluded about consciousness, is exactly what we should expect, suggests Thomas Metzinger in his book Being No One (a précis of the book is here, and he discusses dreaming here). He theorizes that consciousness centrally involves the fact that as cognitive systems we can’t directly grasp that the higher level, informationally integrated and behavior-controlling modeling of the world that the brain accomplishes is a model. Because we-the-system can’t see this, the model perforce becomes for us an untranscendable reality. The existence of the 3D world as we experience it from moment to moment in waking life is just that modeling of the world that we can’t directly recognize as a model. We therefore become, as he puts it, naïve realists; we feel we are in direct contact with reality.
In a lucid dream, we recognize that the experience we are having is a construction, a virtual world. As much as we are having all sorts of fantastic experiences, we know in the back of our minds (and sometimes the front) that we are lying in bed. The truth about consciousness, perhaps, is that waking experience too is a construction, not a direct grasping of the world outside the head. Yes, we are actually walking around in the world, but our experience is generated by the brain just as it generates experience in a dream, but with constraints provided by sensory perception. Feedback from the world forces the brain to adopt a conscious reality-model, as Metzinger calls it, that works sufficiently well to guide behavior; this is what it means to consciously perceive the world. The reason it seems real – is real (as things can get for brains) – is that you don’t experience it as a model, the way you do in a lucid dream. We might (if we agree with Metzinger’s analysis) conceptually grasp waking experience as being a virtual reality, but we can’t experience it as such, that is, adopt a conscious perspective which directly sees waking experience for the construction that it is.
This is why, for instance, severe pain is so excruciatingly real: you cannot for the life of you step outside what is ultimately a critical life-preserving representation provided by the pain system, one that is informing the larger system that it’s at imminent risk of damage or destruction. If you could experientially step outside it, take it as merely a representation, you might put your life at risk. Survival requires us to take some modelings of the world as untranscendably, dead-seriously real, such that we have no choice about it controlling our behavior. Even in a lucid dream, the conscious self that realizes this experience is just a dream and therefore a model, doesn’t experience itself as a self-model, and so takes itself seriously – that is, as real.
Having read this, you won’t find that your conscious experience of things being real, including your self, is in the least attenuated. Your subjective reality isn’t shaken because when we're awake the brain can’t achieve (at least not easily, see below) a perspective that directly discloses consciousness to be a virtual reality. We might attain a cognitive perspective on experience, a conceptual theory about it being a model, but that won’t uproot the subjective seriousness of phenomenology, and the theory neatly explains why.
But it also might help explain why, in rare cases, individuals are able to act against what would seem to be the most forceful promptings of experience. Buddhist monks burned themselves to death in protest of the Vietnam war, sitting still in the midst of self-destruction. Possibly their monastic training had permitted them to attain the direct realization that waking experience, in particular the experience of self, is indeed a construction, such that they were no longer controlled by pain or the thought of death. Perhaps they had awoken, at least to some degree, from the “dream” of the waking virtual world. According to Metzinger, such an awakening would undermine the felt reality of experience (if indeed anything like experience was still happening), so there was no longer a real self to worry about, no pain that couldn’t be ignored. The monks might have been cognitive systems operating without much of an untranscendable reality-model, and for that reason were able to transcend the ordinary constraints of self-preservation.
This gets at an important aspect of Metzinger’s theory, that consciousness is not an all or nothing affair but varies along several dimensions, one of which is the experienced presence of a world. In moments of extreme stress such as a car accident, the world can seem unreal or dreamlike, which is to say that consciousness is not fully activated on the dimension of presence. Similarly, ordinary, non-lucid dreams are less conscious than waking experience in several respects; for instance, the capacity for self-reflection is usually weak or absent, and of course the narrative coherence of the dream world is often severely compromised. In lucid dreams, oppositely, we become super-conscious along a dimension of experiential metarepresentation: we directly apprehend the fact that our current experience (except for the experience of self, as noted above) is a model.
Lucid dreams help us to see that in being conscious we construct a simulated world, we do not directly grasp reality. This realization should keep us humble in our knowledge claims, especially those based primarily on uncorroborated personal experience. Our conscious subjective realities are very selective takes on what exists outside the head, versions of reality that have been shaped by evolution. We get closer to the way the world really is by engaging in the scientific project, which does its best to transcend the distorting effects of subjective realities, which are often colored by motivational biases and perceptual limitations. Science models the world not via a selective phenomenology, but via testable hypotheses that end up amalgamated into our best theories. From a scientific perspective, conscious experience is epistemically adequate for personal and social purposes, but not a particularly perspicacious rendering of reality. Both science and consciousness, however, are essentially representational projects, one collective, the other personal.
Since the waking world isn’t always to our liking, it’s good to know that we can access alternative realities in lucid dreams, not to mention all manner of prosthetic worlds now made available by digital technology. However, although these are palpably virtual realities, which is to say we experience them as models in comparison to the serious business of waking life, our behavior with respect to virtual people can influence how we treat real people. How we conduct ourselves in these worlds and in our dreams reflects on our character, and can even help shape it, so we should act accordingly. Eventually we all get reality tested, acting in a world from which we cannot awake.
TWC, February 2008
 As he puts it, the model is “phenomenally transparent” to us, that is, we look through and therefore don’t see the modeling process itself. This means that only the representational contents of the model (that which is modeled, and not the fact that it is being modeled) are available to us in experience.
 Metzinger and Windt say “At least in standard cases of waking consciousness, lucid insight into the simulational character of conscious experience, which would allow us to detach from our current reality-model and experience it as unreal, can actually be considered as maladaptive.” (Metzinger & Windt, p. 32)