Not so mere matter

There are few things that evoke a more visceral reaction of disgust from theists as the notion that their conscious experiences are the result of "mere" matter. It is the ultimate allergic reaction, almost a mental auto-immune response in which the mind treats the body as a foreign entity. I commented on this phenomenon in the first installment of my essay "Ideas and Consequences", likening it to the reaction that a diner would have on learning that the delicious delicacy he is feasting on was made from elephant testicles. "Blech!" the theist blurts as he spits out the news that his seamless experience of consciousness is "merely" an emergent phenomenon of matter and energy. I vainly asked if instead of judging the phenomenon by its components, we should judge the components by the phenomenon. If life is wonderful, then so is the matter that gives life. Not mere matter, but wonderful matter.

For those believers unable to stomach my advice, I warn you that the following article by Steven Pinker, the Johnstone Professor of Psychology at Harvard University, may result in symptoms of mental queasiness and nausea:

THE BRAIN AS MACHINE

SCIENTISTS HAVE EXORCISED THE GHOST FROM THE MACHINE NOT because they are mechanistic killjoys but because they have amassed evidence that every aspect of consciousness can be tied to the brain. Using functional MRI, cognitive neuroscientists can almost read people's thoughts from the blood flow in their brains. They can tell, for instance, whether a person is thinking about a face or a place or whether a picture the person is looking at is of a bottle or a shoe.

And consciousness can be pushed around by physical manipulations. Electrical stimulation of the brain during surgery can cause a person to have hallucinations that are indistinguishable from reality, such as a song playing in the room or a childhood birthday party. Chemicals that affect the brain, from caffeine and alcohol to Prozac and LSD, can profoundly alter how people think, feel and see. Surgery that severs the corpus callosum, separating the two hemispheres (a treatment for epilepsy), spawns two consciousnesses within the same skull, as if the soul could be cleaved in two with a knife.

And when the physiological activity of the brain ceases, as far as anyone can tell the person's consciousness goes out of existence. Attempts to contact the souls of the dead (a pursuit of serious scientists a century ago) turned up only cheap magic tricks, and near death experiences are not the eyewitness reports of a soul parting company from the body but symptoms of oxygen starvation in the eyes and brain. In September, a team of Swiss neuroscientists reported that they could turn out-of-body experiences on and off by stimulating the part of the brain in which vision and bodily sensations converge.

THE ILLUSION OF CONTROL

ANOTHER STARTLING CONCLUSION FROM the science of consciousness is that the intuitive feeling we have that there's an executive "I" that sits in a control room of our brain, scanning the screens of the senses and pushing the buttons of the muscles, is an illusion. Consciousness turns out to consist of a maelstrom of events distributed across the brain. These events compete for attention, and as one process outshouts the others, the brain rationalizes the outcome after the fact and concocts the impression that a single self was in charge all along.

Take the famous cognitive-dissonance experiments. When an experimenter got people to endure electric shocks in a sham experiment on learning, those who were given a good rationale ("It will help scientists understand learning") rated the shocks as more painful than the ones given a feeble rationale ("We're curious.") Presumably, it's because the second group would have felt foolish to have suffered for no good reason. Yet when these people were asked why they agreed to be shocked, they offered bogus reasons of their own in all sincerity, like "I used to mess around with radios and got used to electric shocks."

It's not only decisions in sketchy circumstances that get rationalized but also the texture of our immediate experience. We all feel we are conscious of a rich and detailed world in front of our eyes. Yet outside the dead center of our gaze, vision is amazingly coarse. Just try holding your hand a few inches from your line of sight and counting your fingers. And if someone removed and reinserted an object every time you blinked (which experimenters can simulate by flashing two pictures in rapid sequence), you would be hard pressed to notice the change. Ordinarily, our eyes flit from place to place, alighting on whichever object needs our attention on a need-to-know basis. This fools us into thinking that wall-to-wall detail was there all along--an example of how we overestimate the scope and power of our own consciousness.

Our authorship of voluntary actions can also be an illusion, the result of noticing a correlation between what we decide and how our bodies move. The psychologist Dan Wegner studied the party game in which a subject is seated in front of a mirror while someone behind him extends his arms under the subject's armpits and moves his arms around, making it look as if the subject is moving his own arms. If the subject hears a tape telling the person behind him how to move (wave, touch the subject's nose and so on), he feels as if he is actually in command of the arms.

The brain's spin doctoring is displayed even more dramatically in neurological conditions in which the healthy parts of the brain explain away the foibles of the damaged parts (which are invisible to the self because they are part of the self). A patient who fails to experience a visceral click of recognition when he sees his wife but who acknowledges that she looks and acts just like her deduces that she is an amazingly well-trained impostor. A patient who believes he is at home and is shown the hospital elevator says without missing a beat, "You wouldn't believe what it cost us to have that installed."

Why does consciousness exist at all, at least in the Easy Problem sense in which some kinds of information are accessible and others hidden? One reason is information overload. Just as a person can be overwhelmed today by the gusher of data coming in from electronic media, decision circuits inside the brain would be swamped if every curlicue and muscle twitch that was registered somewhere in the brain were constantly being delivered to them. Instead, our working memory and spotlight of attention receive executive summaries of the events and states that are most relevant to updating an understanding of the world and figuring out what to do next. The cognitive psychologist Bernard Baars likens consciousness to a global blackboard on which brain processes post their results and monitor the results of the others.

BELIEVING OUR OWN LIES

A SECOND REASON THAT INFORMATION MAY BE SEALED OFF FROM consciousness is strategic. Evolutionary biologist Robert Trivers has noted that people have a motive to sell themselves as beneficent, rational, competent agents. The best propagandist is the one who believes his own lies, ensuring that he can't leak his deceit through nervous twitches or self-contradictions. So the brain might have been shaped to keep compromising data away from the conscious processes that govern our interaction with other people. At the same time, it keeps the data around in unconscious processes to prevent the person from getting too far out of touch with reality.

What about the brain itself? You might wonder how scientists could even begin to find the seat of awareness in the cacophony of a hundred billion jabbering neurons. The trick is to see what parts of the brain change when a person's consciousness flips from one experience to another. In one technique, called binocular rivalry, vertical stripes are presented to the left eye, horizontal stripes to the right. The eyes compete for consciousness, and the person sees vertical stripes for a few seconds, then horizontal stripes, and so on.

A low-tech way to experience the effect yourself is to look through a paper tube at a white wall with your right eye and hold your left hand in front of your left eye. After a few seconds, a white hole in your hand should appear, then disappear, then reappear.

Monkeys experience binocular rivalry. They can learn to press a button every time their perception flips, while their brains are impaled with electrodes that record any change in activity. Neuroscientist Nikos Logothetis found that the earliest way stations for visual input in the back of the brain barely budged as the monkeys' consciousness flipped from one state to another. Instead, it was a region that sits further down the information stream and that registers coherent shapes and objects that tracks the monkeys' awareness. Now this doesn't mean that this place on the underside of the brain is the TV screen of consciousness. What it means, according to a theory by Crick and his collaborator Christof Koch, is that consciousness resides only in the "higher" parts of the brain that are connected to circuits for emotion and decision making, just what one would expect from the blackboard metaphor.

To stimulate the discussion, I ask my readers to answer the following questions:

1. Does the realization that consciousness is a byproduct of matter argue against the possibility of an afterlife?

2. If the answer to #1 is yes, is that the sole objection to this idea from a religious standpoint?

3. What are the implications for morality from this realization?