Archive for August, 2008

Consciousness, qualia, and a creature with an exploding brain

Thursday, August 14th, 2008

I don’t understand all this mystery talk surrounding consciousness and qualia (which appears to go on forever in certain artificial intelligence circles). I think that there are very satisfactory technical definitions for both of them.

Consciousness: the instantaneous state of the mind, including qualia (internal and external perceptions), and reflections. We assume that these are encoded in neural firing patterns, but we shouldn’t forget about the nerve input from various body parts and sensors, as well as the brain configuration and neurotransmitter levels which make a certain firing pattern possible.

Qualia: the part of the conscious state dealing with an external perception. I assume that qualia has fuzzy borders, and the remainder of the conscious state can be, to some level part of it.

Reflections: any part of the consciousness which does not deal with direct perception. It can deal with: past qualia, past reflections, future plans, it can try to envision qualia or perceptions which it had not encountered yet etc.

Why does qualia appear mysterious: because we are not able to reproduce it completely. A reflection about a past qualia can not bring the complete qualia in mind (for obvious reasons). Examples of obvious reasons: we would need to reproduce the external sensory inputs, the neurotransmitter levels, etc.

Why does consciousness appear mysterious: because we are not able to reproduce it completely.

Another issue her is that when we say that we want to “understand” qualia / consciousness, we do not really mean that we want to reproduce a past qualia / conscious state. In fact, reproduction, with some level of approximation, is possible. Eg. I can experience the qualia of eating an apple when hungry. It is harder to reproduce the experience of seeing the Grand Canyon might be difficult to reproduce the second time, as the reflections about past visits will be part of the conscious state.

So the statement that qualia and consciousness are mysterious are simply the (correct) fact that reflections about a qualia are not the brain state as the original qualia. There is the practical obstacle of the fixed wiring of the human brain: for instance, neural patterns in the first level of sensory data processing levels (eg primary visual cortex) are part of the visual qualia, and probably cannot be “borrowed” for a reflection.

I think that the only kind of being who can successfully reflect on its own consciousness is one which (a) has a dynamically reconfigurable brain and (b) has an exponentially expanding brain which at any given moment of time contains its complete previous conscious state as a reflection in the new conscious state.

Now, we can try to visualize for ourselves this creature with the exploding brain, and decide whether we want to be like him/her.

What is it like to be a bat (or Britney Spears, or me, yesterday)?

Sunday, August 10th, 2008

I was re-reading the classic Thomas Nagel paper “What is it like to be a bat?”. First, of course, one need to accept the premise that there is something like “subjective consciousness”. But, let us take this premise and run with it.

What Nagel is arguing is that there is no way for me, a human, to know what is it like to be a bat, because we cannot recreate the experiences of a bat. We have a different brain and body structure, we do not have a wing, we do not have a sonar, and so on.

I think that he is right, but he is missing the real gap.

What about trying to understand what is it like to be Britney Spears? I don’t have her gender, age, experiences. One might claim that structurally I am closer to Britney than to a bat, so maybe my understanding of how it is to be her might be “closer” (provided I can create a distance measure on such a thing).

But now an easy one (for me). What was it like to be me, this morning? The facts are there: the sun was shining, and I was having a headache. My perceptions of the external world and the internal world created something which Nagel would call “experience”. Right now, the headache is gone and it is nighttime. I can describe my feelings this morning, verbally, but I can not trick my mind to feel a headache or my eyes to see sunlight.

I do not know how it was to be me this morning. The gap between the actual moment of experience, and the attempt to reproduce it later is much larger, than the gap between my experiences, Britney’s experiences, or the bat’s.

PS: Of course, I know what it is for me to finish writing this blog entry. But wait… it is gone.