Dual-Brain psychology is the name
I gave to the overall theory and practice of psychology which follows from
my research and clinical practice. I articulate this reach and its
application fully in my book, Of Two Minds, and in my scientific papers.
Here I will give a brief description of dual-brain psychology, but the best
way to appreciate it is to read Of Two Minds.
The central idea behind dual-brain psychology is that we are essentially of two minds, one associated with each hemisphere. At first, this suggestion sounds too cleaver and convenient to be a serious idea. But, the idea was the result of 20 years of clinical practice and 10 years of laboratory research as well as a deep review of the relevant scientific literature . The idea began years ago when I noticed in my clinical practice of psychiatry that my patients didn't seem to fit well with Freud's idea of an id and ego, but seemed to fit better with a model which suggested that they had an immature part of their personality which was much more full than the idea of the id. The id was seen as an unconscious cauldron of raw impulses usually of a sexual or aggressive nature. What I was seeing was a more complete mind with ideas and feelings, but a mind which was more like a child's mind. Freud and I were essentially talking about the same thing. Both of us saw this part of the person as immature and impulsive, but I felt that in my office I could see an actual part of the patient which was child like and immature and impulsive. I could also see (in a typical patient) another part which was more adult, more mature and responsible. I also could see (like Freud) that the immature aspect was often adversely affected by past traumas and that often in my practice these traumas occurred in childhood when people tend to be most vulnerable.
I then became reacquainted with the famous split-brain studies. These studies were performed on patients who had had a rather drastic brain operation to try to help control life disrupting epilepsy. The operation, pioneered by neurosurgeon, Joseph Bogen, was the so called "split-brain operation" or commissurotomy in which the large nerve bundle connecting the left and right brains was severed. Perhaps the most surprising result of the operation was not that it helped the patients (which it greatly did), but rather that the patients seemed to be relatively unaffected by this drastic surgery. Bogen, working with Roger Sperry and Michael Gazzaniga, followed these patients with innovative laboratory studies called "the split-brain studies." Essentially, the typical study entailed flashing a picture to one side or the other of the split-brain patient. It has long been well known that images shown to the left side of a person are seen first by the opposite (right) hemisphere first. The image can then be passed easily through the connecting nerve bundle to the other hemisphere in normal people. In a split-brain patient, with that connection cut, the image stays in that hemisphere and is viewed only by one side of the brain. To show an image to the left brain of a split-brain patient, the experimenters flashed a picture to the patients right side (his right visual field). In this way the researchers were able to show pictures exclusively to one side or the other of the brain.
When a picture was flashed to the right side of the split-brain patient, he could easily tell what was in the picture (keys, a pipe, a banana, whatever) just like a normal, unoperated person. This is because speech is located in the left brain. When pictures were flashed to the left side of the patient, going to the right brain, he kept saying, "I can't see a picture." When the experimenters then asked the patient (who just said he couldn't see the picture) to reach behind a screen and reach into a box with several items such as a key, pipe, glasses, he would always, that is always, pick out the item which had been flashed to his right brain.
So what was going on? It turns out that the right brain did see the picture and understood what was in the picture. But, the right brain does not have a speech center, and so it couldn't tell the experimenters what was in the picture. When the patient said he didn't see it, it was his left brain which was talking! And his left brain did not see the picture because it was shown exclusively the right brain. Although the right brain couldn't speak, it could answer the question with its hand, much like mute people do.
In later experiments, these patients were shown photographs of famous people. Again when they were shown to the left brains, the patient's could identify the person in the picture and verbally report that to the experimenters. This is just like what an ordinary person would do. But, when the picture was shown to the right brain, the mute brain, the person could not verbally report what he saw. The experimenters decided to have the patient use a thumbs up or down signal with their left hand when the pictures were shown exclusively to their mute right brains. The first picture got a thumbs up, the second a thumbs down, and the third a thumbs horizontal. The first was a picture of Johnny Carson, the second, Hitler, and the third Nixon.
What this means is that the experimenters were in effect able to have two separate conversations, one with each hemisphere, left and right. Note that the mute right hemisphere has an intact mind separate from the verbal left sided mind. The right sided mind can't speak, but it does understand English, knows how to follow the experimenters' instructions, and even holds political opinions.
Most studies on split-brain patients, with a few exceptions, did not deal with psychology, but focused on the language and special abilities of the two hemispheres. I wanted to test whether the two hemispheres of split brain patients were different from a psychological perspective. I had been in contact with Joseph Bogen, and he thought the experiment I proposed might be interesting, and he put me in touch with his colleague, Eran Zaidel, who agreed. I flew out to Los Angeles, and in one weekend we completed an entire study which was recently published.
The most fascinating findings which we reported in the paper about one patient who told me he had been bullied as a child. I asked him (his left brain) whether the bullying still upset him, and he replied that of course it didn't, it happened 30 years earlier. When we tested him we were able to ask questions separately to both hemispheres and have each hemisphere answer with the left (right brain) and right hands. Interestingly, his left hand indicated (speaking for his left brain) that, as his left brain told me verbally, he was not upset about the bullying. But, his left hand responses, speaking for his right brain, indicated that he was extremely upset by the bullying even after 30 years! Click here to see the published paper .
So this experiment was consistent with what I thought I was seeing in my patients: two separate minds, perhaps, one associated with each hemisphere. Still, this was just a very tentative hypothesis based largely on my interactions with my patients. Then one day I was reading some scientific literature and came across an interesting article. In that paper by a German group of scientists led by Werner Wittling, they reported that they could show movies to the left or right brains of ordinary people. Essentially, they were showing the movie to one side of the patient and the movie would apparently have more of an affect on the opposite hemisphere. They found that depending on which side of the person they showed the movie, the person's blood pressure, heart rate, cortisol level, and emotional response would vary. The effects were not very strong but they were statistically significant.
I decided to try a simple experiment. I held my hands up and covered my eyes so that I could see only out of the left side of my left eye, and asked myself how I felt. I felt fine and no different than I ordinarily did. I then tried looking out the other side, and again, not surprisingly, I felt no different. I wondered what Whittling had actually found. Perhaps his findings were so small that they weren't clinically relevant.
Another person might have left that experiment there and gone on to reading another article. But, I had to go to the office to see patients. There I decided, expecting nothing much, to ask my first patient to block his vision as I had. He almost immediately said, "Oh, my God!" "What's that?" I immediately replied, and he said, "I've got all of my anxiety back." I asked him to try looking out the other side and he said, "Oh, that feels great."
That day five patients of 8 had similar intense responses. And as long as the person looked out that view, he would seem to have a different perspective on the world than he had looking out the other side. Out one side he manifest a more mature personality and out the other a more immature personality. This was exactly what I had expected from my psychological hypothesis. In my book I present many transcripts of sessions using this technique (later with taped safety goggles and then later with specially designed sunglasses). If you want to try this your self, try my envelope test.
I then began using these lateralized glasses as an adjunct to therapy with patients in my practice. You can see a brief excerpt from my book, in which there is a description of my using the glasses with a patient . My book, Of Two Minds , offers many such examples. Essentially, I see therapy as the teaching of the immature side that it is safer and more valuable than it had thought, and I have found that using these special glasses as an adjunct to therapy can be of great value in those patient who are responsive to them. A typical responsive patient might say, looking out one side, "I'm stupid and lazy." With that view he will feel anxiety and depression. Simply having him put on the opposite pair of glasses, waiting 15 seconds and asking again how he feels about himself now gets an entirely different response. "Hell, I'm the most ambitious person I know." His anxiety and depression are gone! To experience this is a profound experience, and is of course contrary to all of our expectations. Even after having witnessed this phenomena hundreds of times, I still feel amazed each time I see it.
In patient who do not respond to the glasses, and this is about 40% of my practice, I have found that the model of our having two minds is still quite helpful to the patient in his or her attempts to better understand and help him or herself. I have found that patient who are responsive to the glasses do seem to get well more often and faster.
Thus, Dual-Brain Psychology refers to my ideas about our having two aspects to our personality, one more mature and one less mature, each associated with the left or right brains. It is also about the scientific literature and laboratory experiments which support the psychological theory, and finally, it is about using these ideas with or without the glasses in therapy.