(Courtesy of the author)
The real advance in the research program, however, came not from the testing gear and trailer, but from my bevy of new graduate students. Energy and smarts is what counts, and they all had it. Our frequent road trips to New England became legendary, and of course they were fun. When new postdoctoral fellows would come to be interviewed for jobs, they were intent on reviewing what they had accomplished in their thesis work. I would look at them blankly as they finished, because, even though they all had accomplished something of value, I had a critical question: “Do you drive?”
DON’T QUIT YOUR DAY JOB
The penal colony architecture of the State University of New York, Stony Brook, was an anomaly in the otherwise idyllic setting of the Long Island shore. Stony Brook, Setauket, and Port Jefferson, snuggled into the north shore, were roughhewn and breathtaking. Governor Nelson Rockefeller decided to compete with the University of California system in the early 1960s by building Stony Brook, but something went wrong in the design department. It was as if the designers had never left Albany to look at the gorgeous setting and see its aesthetic potential. For years, articles were written about the depressing nature of the campus and reported all over scientific journals.
None of the physical shortcomings of the university, however, seemed to thwart their hiring of a terrific faculty. By the time I joined the university, it had been in business for only eleven years. Even though New York State had imposed its awful bureaucracy from the start, the campus’s energetic faculty made it feel like a Silicon Valley start-up. Collaborations were easy to form across disciplinary lines, and I was beginning to think about combining biochemical approaches to the study of learning by using split-brain pigeons. Maybe Stony Brook would be a place to do that, too.
As I said, energetic graduate students are the key to so many adventures in science. Eager and committed, they find you. If they’re smart, stuff really begins to happen. They are the legs, the energy, and the future for any science, and Stony Brook had more than its fair share. One of them, Nicholas Brecha, showed an interest in the wacky pigeon idea and is responsible for getting it off the ground.20 The project required learning a sophisticated behavioral training method, anatomy and surgery, and, of course, biochemistry. Before you knew it, Brecha had mastered all three by calling upon campus specialists, all of them scientists in their own right. After a few years of hard work, the project was completed, and, unfortunately, we couldn’t find any differences between the trained and untrained half brains of a pigeon. The bet was placed, the work was done, and bupkis. That is the way it goes and why one always has side projects. Brecha, for example, went on to a successful career and is now an expert on the retina and a professor of medicine at the University of California, Los Angeles.
Many of my other projects were outside straight academic work. Ever since my Sol Hurok days as political entrepreneur at Caltech and my failed attempt to start a new audiotape company with Bill Buckley (another story), I was stuck with a compulsion to be unconventional.
Steve Allen Jr., the son of my late comedian friend, is a physician. We became quite close, and he encouraged the wacky idea I had to make science documentaries. He is hysterically funny, humane, and, like his father, captivated by brain research. At one point, we cooked up an idea to make a film about the brain and creativity. After my move to Stony Brook, I had the Beaulieu 16 movie camera that allowed for sound to be recorded right on the film during filming. This was an improvement on the old Bolex 16 that I had used at Caltech, with its double-sprocket film and its awkward process for adding sound. I thought the Beaulieu would make editing and production easy. While the camera was bought to use for my patient work, I thought it could double as an aid to the noble goal of scientific education.
The camera, parabolic sound microphones, lights, and all the rest required several bags. All of them were heavy or awkward to carry by myself. Undaunted, I called Steve Sr. and asked if I could interview him about creativity. He couldn’t have been more agreeable. Off to Los Angeles I went, carrying film gear through airports with a certain swagger.
I arrived at his home one Saturday morning, and Steve was still lounging around in his blue robe. I didn’t think people actually lounged in their robes except in the movies. He walked me into his living room and suggested ways for me to set up the lighting, tripods, and all the rest. It all started to become surreal, and this little voice in me said, What are you doing? Why are you bothering this guy in his robe? Why aren’t you back at Stony Brook doing your research? Who do you think you are—Fellini? I was just about to leave, making some excuse, when Steve said, “Looks like you are ready.” With that he started to play one of his own compositions, “This Could Be the Start of Something Big,” and for a moment, I did think I was Fellini. The experience was exhilarating, and I vowed to take my gear everywhere to capture moments for the film. In fact, I took the gear to Paris a bit later, set it up in my hotel room at the Paris Hilton, and threw open the window. With the camera on automatic, I filmed myself standing in front of the window, with the Eiffel Tower in the background, and thought my second career was launched.
Oh my, we do crazy things. After filming a ride up the Eiffel Tower and a tour around half of Paris, I went home, loaded up with my footage. With great anticipation I waited for it to come back from being developed, stuck it in my projector, and sat back to savor my ingenuity. Let me simply say my escapade into filmmaking ended abruptly. My favorite disastrous scene was the one in the hotel window. Because my camera was reading the light level of the bright Paris sky, the guy in the foreground looks like he is in a witness protection program. Of course, one always looks for the silver lining. Steve looked terrific in his robe.
NEW PATIENTS, NEW DISCOVERIES, NEW INSIGHTS
Meanwhile, the research team was forming to tackle the new human split-brain work. Gail Risse led the charge, and others were soon to join. I also brought my monkey program out from NYU and loaded it up with new students, such as Richard Nakamura, who years later became the deputy director of the National Institute of Mental Health. We were busily exploring the question of whether one brain was as good as two. Cigar smoking and gentle, Richard preferred to stay with the monkey work. Meanwhile, Joe LeDoux was losing interest in his animal project, and I recruited him into the human work.
The split-brain team worked hard but at first the results were thin. The first patients were a complicated group. While the neurosurgical reports suggested that most of them had had a full callosal section—reports we accepted at face value—it was evident, upon much neuropsychological testing, that the surgery had not been complete. Before we knew the reports were flawed, we thought we had discovered an interesting fact. Unlike the California patients, who had both the callosum and anterior commissure sectioned, the new patients explicitly had the smaller anterior commissure intact. If any kind of information transferred between the hemispheres in these patients, we, not knowing that their callosal sections were incomplete, assumed it would be due to the intact anterior commissure. We knew that an intact anterior commissure in a monkey allowed for all kinds of visual information to transfer.21
In the end we got it right, but we definitely went through a phase where we got it wrong, which became evident when we combined months of neuropsychological testing with newly emerging EEG data from the Dartmouth neurologists.22 At first we thought we had seen evidence for transfer of visual, somatosensory, and auditory information between the hemispheres and concluded the anterior commissure was the source of that cross-integration. We began to think animals and humans were more alike than not on this parameter.
It turns out that the first group of patients had variations in their partial disconnections. Some were partial splits by design. For example, a case might undergo anterior callosal surgery first. If the seizures came under control, then no further surgery was carried out. In other cases, though, there was inadvertent sparing of the anterior callosum. For example, in one case the anterior callos
um was sectioned, and months later the posterior callosum was sectioned. The surgeon, however, had inadvertently left some anterior callosal fibers where the two surgical sections were to intersect. At the time, neither we nor the surgeon knew this. This patient showed transfer. We assumed it was due to the uncut anterior commissure, since we all assumed the first surgical reports were correct and a complete section of the corpus callosum had been accomplished. A few years later, the EEG results illuminated the story.
These roller-coaster results were no fun. We were beginning to back off from testing our New England patients when it all changed and we began to learn some things. The parts of the callosum that were sectioned did produce some specific modality deficits in interhemispheric integration. That is, specific areas of the callosum integrate specific kinds of sensory information such as vision and touch.23 But it was indirect evidence and it wasn’t clean. We were all beginning to think we should begin other avenues of research.
Then along came Case P.S., a teenager from Vermont, who led us out of our confusion and revived our interest. P.S was reported to have had his entire callosum sectioned in one operation by the Dartmouth surgeons. Even though the Dartmouth procedure required leaving the anterior commissure intact, he was “split,” for sure. In a matter of weeks it was clear as a bell that a truly fully sectioned callosal patient with the anterior commissure unsectioned was identical to the Caltech patients in terms of the disconnection effects. Nothing transferred between the hemispheres; each hemisphere seemed specialized in its own way. The trips to Vermont became monthly and stayed that way for many, many years.
Many things were immediately evident upon testing P.S. There was, flat out, no interhemispheric transfer of visual information. Visual stimuli presented to the right hemisphere stayed isolated to that hemisphere and could not be named or described by the left hemisphere. This meant the anterior commissure did not transfer visual information as it had in the patients who still had some uncut callosal fibers. P.S.’s tests offered evidence that the human brain was organized differently than a monkey’s brain; a fully callosal-sectioned monkey with an intact anterior commissure could transfer visual information between the hemispheres. Of course, it also meant the Dartmouth, or East Coast cases, as they were to be called, were just like the California cases. This fact would prove to be a sore point between the two research groups in the years ahead. In ideal science, replication is key and a virtue, and everyone warmly collaborates. But science conducted by mere mortals often falls short of this ideal.
LeDoux was amped (Figure 20). His introduction to the so-called split-brain patients had been the earlier patients in the Dartmouth series, and while of interest, they were not compelling. Case P.S. was loaded with phenomena, and LeDoux captured many of them. He knew the earlier scientific literature cold and would say, “Let’s try this,” which might be to ask the patient to draw a cube with the left or right hand. After experiencing months of confusing responses that had come out of the first group of patients, his jaw dropped when he saw P.S. easily draw a cube with his left hand but not be able to do so with the right hand. Back in our sparse motel room that night, I can remember LeDoux saying, “We finally have ourselves a split-brain patient to study.”
FIGURE 20. Joseph LeDoux was one of the first scientists to work with a viable series of split-brain patients out of Dartmouth. Today he is considered one of the neuroscientists primarily responsible for the scientific study of emotion. On the left is the GMC van that Joseph convinced the National Science Foundation to buy us so we could continue our work.
(Courtesy of New York University)
In trip after trip, the dynamic nature of P.S.’s postsurgical course revealed itself (Figure 21). Unlike Case W.J., the arm ipsilateral to a particular hemisphere quickly came under the control of that hemisphere. Again, that meant either hemisphere could come to control not only the contralateral arm, but also the ipsilateral arm. And that meant drawing a cube correctly could soon be accomplished by both arms/hands.24 LeDoux logged all of these changes, and within fifteen months, both hands were equal in skill. This learned control of both arms was evident in the other California patients, so it was not surprising. Still, it is exciting to see things unfold like they are supposed to.
FIGURE 21. Case P.S., the case that put us back on track. He was a warm and affable teenager. On one of our trips to California to study his brain waves, we took him to Disneyland. Here he is pictured on the trip with his mother.
(Courtesy of the author)
P.S. was unique in so many ways, not the least of which was his spunky right hemisphere (Video 7). Very soon after his surgery, the right hemisphere, while unable to speak, was very responsive when nonverbal outlets were available to him. He was the first split-brain patient to respond to verbal commands to the right hemisphere, in addition to simple nouns. If a noun, such as the word apple, was flashed to the right hemisphere and he was asked to point to a picture that matched the word from among a set of pictures, P.S., like other split-brain patients, had no problem. Yet, unlike other patients, when a simple printed command was given to the right hemisphere, like “get up” or “point,” he could do that, too. The right hemisphere didn’t sit there like a lump on a log; it did stuff (Video 8). In fact, as we were soon to discover, it could have its own preferences. Having a more engaged right hemisphere to work with opened up all kinds of issues and studies (Video 9). LeDoux describes everything better than most people, especially me. He was my partner in all of these studies:
Patient P.S. was especially important. He could use both sides of his brain to read but only the left hemisphere to speak. Previously, the right hemisphere had been thought of as a lesser partner, with cognitive capacities like a monkey’s or chimp’s, but not like a human’s. The left hemisphere clearly had self-awareness, but whether high-level consciousness was possible on the other side as well seemed dubious. With P.S. we were able to ask whether the right side was self-aware because his right hemisphere could read. So we flashed questions to his right hemisphere and his left hand would reach out and, using Scrabble tiles, spell the answers. In these simple tests we found out that P.S.’s right hemisphere had a sense of self (he knew his name) and had a sense of the future (he had an occupational goal), both important qualities of conscious awareness. It was particularly interesting that the right and left hemispheres had different goals for the future. Might there indeed be two people in one head?
In the process of testing the interactions between the two sides, one day in our camper trailer lab, Mike made an important observation. We were giving the right hemisphere written commands (stand, wave, laugh), and P.S. responded appropriately in each case. Had Mike not been there that’s probably as far as it would have gone. We would have been happy to have shown that the right hemisphere could respond to verbal commands. But Mike’s incredibly fast and creative mind immediately realized there was more to it. He started asking P.S. why he was doing what he was doing. Remember, only the left hemisphere could talk. So when the command to the right hemisphere was “stand,” P.S. would explain his action by saying he needed to stretch. When it was “wave,” he said he thought he saw a friend. When it was “laugh,” he said we were funny.
That was the birth of Mike’s theory of consciousness as an interpreter: a reason for doing these things was made up to justify the impulse to take a certain action. This led to more experiments to directly test the idea.
On the next trip we simultaneously presented different pictures to the two hemispheres and told him to point to the card that matched the pictures. In the classic example, we presented a snow scene to the right hemisphere and a chicken claw to the left. The left hand pointed to a card picturing a chicken and the right hand to a card picturing a shovel. P.S. explained his choices saying he saw a chicken claw so he picked the chicken, and you need a shovel to clean out chicken shit in the shed. The left hemisphere, in other words, used his behavioral responses as the raw data to concoct an interpretation that was then acce
pted as the explanation of why he did what he did.
For the left hemisphere of a split-brain patient, everything done by the right hemisphere is an unconscious act. Mike proposed that our behaviors are controlled by systems that function unconsciously, and that a key function of consciousness is to make sense [of] (interpret) our behavior. This was his theory of the interpreter. . . .25
Joseph’s flattering retelling of those trailer days fails to fully capture his role in the discovery. When something happens in a setting like that, everybody is equally involved. It’s mutual cueing all the way and our only chore is to make sure the patient is not in on it. He wasn’t.
In a sense, the insight that P.S. provided us (that the left hemisphere would come up with an explanation that made sense of the behaviors initiated by the right brain) came from changing our mind-set, not his. For the previous twenty years, split-brain researchers were intent on seeing what a particular hemisphere could do and could not do and whether there was information transferred between the hemispheres. This led us to ask a certain kind of question in a certain way. After we presented a stimulus to one hemisphere or the other we would ask, “What did you see?” It wasn’t until twenty years later that we finally wondered, “What does the left speaking hemisphere think about all these things the right hemisphere is doing?” After all, the left hemisphere has no clue why the behaviors are happening. Finally, it dawned on us in that cold trailer. Joseph and I asked, “Why did you do what you just did?” In simply changing the question asked of the patient, a virtual torrent of new information and insight flowed. Though the left hemisphere had no clue, it would not be satisfied to state it did not know. It would guess, prevaricate, rationalize, and look for a cause and effect, but it would always come up with an answer that fit the circumstances. In my opinion, it is the most stunning result from split-brain research.
Tales from Both Sides of the Brain : A Life in Neuroscience (9780062228819) Page 15
