The study of the brain is really only about 150 old. And as recently as 100 years ago there were arguments about whether at least the cerebral cortex was intrinsically specialized or was some how able to assign any task to any part. We’ve made a tremendous amount of progress to the point that many neuroscientists are willing to talk about human behavior in terms of the brain, leaving consciousness and mind out of the equation.
This attitude generally called materialism or functionalism is placed firmly within the scientific tradition of studying only that which can be weighed and measured. While I’m a neuroscientist and professionally interested in the advancements of brain science, I’ve always found this disregard of mind troubling. Its as if the most important part of human experience is being ignored or, worse, just explained away.
I’m reading Michael Gazzaniga’s Human: The Science Behind What Makes Your Brain Unique
For example, Gazzaniga has a nice discussion of the data showing that the mind frequently makes up reasons for actions after the fact. This post-hoc rationalization by the mind is especially true for emotions triggered in a way that avoids conscious awareness of the input. Normally, emotionally charged stimuli like disturbing photographs go to all parts of the brain simultaneously, so the mosaic of the brain acts in concert. Our minds are normally in sync with our feelings.
One dramatic example is the split brain patients that Roger Sperry and then he, Gazzaniga, studied. These patients have had surgery for severe, uncontrollable seizures. In an attempt to stop the spread of seizures, the major connection between the right and left half of the brain was surgically cut. Sperry described how these patients can appear to have two minds in one brain. If, under experimental conditions, information is presented to half of the brain only, the other half doesn’t have access to the information. So if half the brain is asked to do something, for example peel and eat a banana, the other half of the brain doesn’t know why. When asked, the ignorant other half makes up plausible rationalizations, saying for example, the banana looked tasty.
In normal volunteers these effects can be studied with presentations of pictures for a very short time, too short to percieve consciously. They register and can provoke feelings that are not available to conscious perceptual systems. So the subject rationalizes why an emotion is being felt. It seems likely to me that this kind of rationalization occurs in people with mood disorders. Even if the mood is generated internally, one will tend to explain it based on external events.
Some one who’s depressed will walk through life seeing many things as depressing just to rationalize why they feel sad.
Materialists like Gazzaniga want to use this kind of data to convince us that all there is is brain. These mental agents in the brain are just some kind of internal explaining agents, which of course makes the brain the motive force for an individual. The mind becomes like some kind of narrator trying to make sense of it all.
Yet there’s a very telling phenomenon called reappraisal that shows that mind does affect emotion. It’s a two way street.
An external event can trigger a strong emotion. For example some one yelling and shouting stirs up all kinds of feelings in us. But as soon as we realize that the shouting is not at us, but at some one else, the emotions melt away quickly. When you realize that the police lights in the rear view mirror are just passing and not pulling you over, the fear turns to relief. There’s almost a limbic decay constant you can feel as the feeling evaporates over a few seconds.
As john Searle points out, materialists have an easy time going from brain to perception, but a much harder time seeing mind affecting brain, mind being causitive. The problem is that because they dismiss mind as being unreal, they are left with this strange residual of consciousness that we all percieve, we all think is causative in the world, but doesn’t seem to really exist. How can something that isn’t real do anything? These strict materialists end up sounding like dualists because they recognize brain and brain events only. The mind is unexplained except for being some kind of hidden brain process.
Adopting the attitude that mind is real, embodied in the brain, allows one to see the role of mind in the world. And there is a fascinating interplay between the mind and perception of the world, both external world and the internal world of body signals like hunger and fear.