The Complexity Trap

It’s hard to prove that the conscious mind is located in the brain. One problem is that both mind and brain are incredibly complicated, and it’s hard to map one sort of complexity onto the other. Popular media sometimes imply that science has accomplished this feat, but this isn’t so.

Suppose we ask subjects to visualize a square, then a circle, then a square again, while their brains are scanned for signs of neural activity. And suppose this experiment enables us to print out colorful pictures showing that brain regions 1-2-3 are especially active while subjects visualize squares, and regions 4-5-6 are especially active while they’re imagining circles. Does this show that the experience of fantasizing squareness is located in 1-2-3 and fantasizing circularity is located in 4-5-6?

Not at all. It’s a start, but barely that, and I’ll just mention two of the many difficulties.

1. How much of a lit-up region is the experience of the item, and how much of it is a motley assortment of non-experiential accompaniments? Visualizing a square may call up all sorts of associations with square items and with the word “square” – square meal, square deal, square mile, and “you’re so square.” Perhaps activity in linguistic regions involves verbal associations only, and is never part of the mental image itself. Perhaps. But we don’t know for sure.

2. It’s also hard to know which aspects of a brain’s activity are conscious processes and which are the unconscious accompaniments. A great deal of the brain’s visual processing, for example, never reaches the level of awareness.

Someday we may be able to detect precisely which neural activities constitute, say, a visual experience of seeing a single cherry blossom, but this will certainly not be easy. Compare the task of identifying precisely which electromagnetic waves in the signal from a TV satellite constitute an image of the seams of a football being passed during the last five seconds of the 2015 Superbowl. We assume that this part of the video signal is a physical event, and our inability to precisely specify it does not make us philosophically puzzled. But the difficulty of knowing just which brain activities constitute a particular experience may make us wonder whether this experience could be in the brain. Complexity confuses us, so beware of the complexity trap.

I recall a lecture in which the speaker announced that he was going to display his model of the neural correlates of consciousness, or NCC. The NCC is whatever cluster of neural activities correlates with conscious experiences, and finding such a correlation would be a big step toward showing that experiences are constituted by neural processes. He then showed us a diagram with about 50 arrows going in all sorts of directions.

He was joking, of course, because we have no idea how to sketch the NCC. We need to remind ourselves that the brain is much more complex than we can comprehend, and that we are in this convoluted mish-mash.

Roger Christan Schriner

Advertisements

Conscious vs. Unconscious

I’ll now resume blogging about consciousness, and in general I hope to post an entry at least every two weeks. Today I want to contrast conscious and unconscious states of mind, things that we do and do not experience. Right now, for example, notice the sensations in your legs. You probably weren’t aware of them a moment ago, unless they were uncomfortable. And yet your brain was continually receiving neural signals from those lower limbs. If a rattlesnake had started slithering up your ankle, you would hopefully have noticed a change in those sensations. (Did you feel a creepy little tingle in your calves, just reading that last sentence?) Complex sensory information is constantly flowing into your brain, but the brain has cerebral sentries posted, tasked with letting some things “into” consciousness and keeping others out. These gate-keeping mechanisms recruit a small fraction of your current perceptual inputs into sensory awareness.

The difference between consciously “present” and non-conscious mental events is partly a difference in the way we know things. If I’m paying attention to my legs I know they exist because I can feel them. But suppose someone gives me a drug that prevents me from feeling my legs for the next hour, and blindfolds me as well. Although I would still know my legs exist, “knowing my legs are there” without being conscious of them is different from knowing my legs through feeling them and seeing them.

Is everything in your mind either conscious or unconscious? Some say yes and some say no. I suspect that in borderline cases there is no fact of the matter about whether a mental event is conscious. For example, I was once watching a TV show about hippopotamuses. My mind began to wander and suddenly I realized that the TV had been showing zebras instead of hippos for a minute or two. It seems likely that in some sense I did experience the shift from one animal to another. I was looking right at the screen, and the shapes I was gazing at were a lot different when the striped beasties went away and the much portlier hippos began cavorting. But at first I was not fully aware of this change. So there may be a gray area of semi-awareness. Even so, most would agree that some mental events are clearly conscious and others are definitely unconscious.

In case you’d like to practice focusing on your own stream of consciousness, here is a way to do that.

Just notice. Sit or lie down in a quiet place, set a timer for perhaps 10 minutes, close your eyes, and notice the flow of your own awareness. Start with sound-experiences. Every time you hear something new, even if it’s very soft, just think sound. Then after a while, do the same thing with bodily sensations, thinking body in each case.

Eventually you can do this with everything that moves through your mind: smell, taste, thought, emotion, sight (noticing visual patterns with your eyes closed), and so on. Of course at times you will start pursuing thoughts about some topic and fall away from this exercise. Just say the word “thoughts,” silently, and return to your focus, until the timer rings. This standard meditation technique has numerous benefits in addition to acquainting us with our own mental processes. It will help you become more “conscious of consciousness,” more aware of your own inner life.

Roger Christan Schriner