Working as a young neurosurgeon in Jacksonville, Pribram was given a ward of lobotomy patients to oversee. Though lobotomies were a common procedure in psychiatry in the 1940s and early 1950s, none were done while he was running the ward. Pribram felt that there was not enough solid knowledge of brain function to justify the widespread use of lobotomies.

His dissatisfaction led him to careful experiments on laboratory animals. One of his key findings was that the frontal lobes were tied to the limbic system, especially the amygdala. In a classic series of experiments, he showed that monkeys who had the frontal lobes or amygdala removed could still be assertive under certain circumstances.

Pribram directed Yerkes Labs briefly after Lashley’s retirement, and then went to Yale in 1948, where, during his 10 year stay, he did pioneering research on the limbic system. The limbic system, a string of brain centers that includes the hippocampus and the amygdala, was then thought of as an olfactory brain, mainly involved in the sense of smell. Pribram was first to show that the system was far more complex in its role, and that visceral as well as olfactory information was processed by these structures. (He is only now pulling together 30 years of papers that will be published in three volumes under the title of The Primate Forebrain.).

In 1960, Pribram once again challenged the prevailing wisdom in a book that he wrote with George A. Miller and Eugene Galanter called Plans and the Structure of Behavior. Until then, both Miller and Pribram had been staunch behaviorists. But in Plans, they declared that the assumptions about brain and behavior that were the underpinnings of the behaviorist school were mistaken: Pribram's contribution was the notion that brain cells did not work as a simple reflex arc, but, rather, were part of an elegant feedback circuit. It was no longer enough to talk about the brain as, "an empty black box" between stimulus and response. Declaring themselves "subjective" behaviorists, the three authors gave impetus to the cognitive movement, now one of the dominant fields in psychology.

One way of mapping fashions in an academic field is through the authors cited in journal articles. When I mentioned that to Pribram, he agreed, laughing: "That's right. My older work is widely cited, but my newer work seems to be off the map!" If some fellow neuropsychologists have shied away from Pribram's current interests, new allies have emerged in other sciences aid the hinges of the consciousness explosion. He is collaborating with physicist David Bohm, a professor at London University who once worked with Albert Einstein and who is also close to philosopher mystic J. Krishnamurti.

Pribram thinks of himself as an innovator rather than a renegade. He to accustomed to the resistance of colleagues, who have usually come around to his way of thinking in the past. Only time will tell whether he has gone too far with his speculations on holographic theory, but Pribram's past record suggests we are in for a lively debate.


Does the hologram, a three dimensional image re created from the patterns of laser light, provide the long sought model of how information is distributed and stored in the brain? Karl Pribram, the Stanford neuropsychologist, argues that it does, and his theory may have staggering implications for our perception of reality.

On one of the bolder frontiers of science, there is a curious alliance forming among neuropsychologists, quantum physicists, and mystics. A leading theorist in the movement is Karl Pribram, a 59 year old neurosurgeon psychologist whose research on the brain at Stanford University sometimes makes him as comfortable with the thinking of mystics as with the concepts of behaviorists, among whom he once counted himself.

Pribram proposes nothing less than a new scientific paradigm for studying mental processes, a hypothesis that could explain some of the classical paradoxes of brain function as well as some paranormal and transcendental experiences. The Stanford scientist believes the brain operates according to the same mathematical principles as a hologram. Brain researchers seem to agree that memory is a result of biochemical changes in the brain and is stored in individual cells to be recalled when electrochemically activated. What Pribram's theory purports to explain is why traces of the same memory have been proven to exist in more than one area or part of the brain, or how memory comes to be distributed through the brain.

He argues that the process is the same as the mathematical transformation that occurs when a three-dimensional image is projected into space in holography. Initially, the notion of a neural hologram was only a metaphor. But now, Pribram believes there is sufficient laboratory evidence to demonstrate a physiological basis for the model.

Some brain researchers, among them Nobel Prize winner Sir John Eccles, have disagreed with Pribram’s holographic theory on technical points. Others object to some of his wide-ranging speculations about its relations to our perception of reality.

Neuropsychologist Frank Wood of the Bowman Gray School of Medicine in Winston Salem, North Carolina, calls Pribram's model "a modem science echo" of Aristotle's theory that ideal forms dominate mental life at all levels, from the biological to the social. Wood sees it as offering "potentially penetrating insights into the basic nature of brain function."

But Wood feels the hypothesis has its limitations, "such as the fact that there are precious few experimental findings for which holography is the necessary, or even preferable, explanation. Indeed, some aspects of the neuropsychology of memory . . . may not fit the holography analogy at all." Moreover, Wood observes, "many brain researchers would have reservations about Pribram's application of holography to explain phenomena like the paranormal."

But Pribram's brilliant research career has surely earned him the right to speculate. He has played a large personal role in putting neuropsychology on the scientific map; many of those currently making significant contributions to the field arc his former students or research partners.

To explore Pribram's theory, and his speculations on it, PT associate editor Daniel Goleman visited Pribram in his Stanford laboratory. This is how their talk went:

Daniel Goleman: History tells us that, with every paradigm shift in science, a new frontier of legitimate investigation opens. And from that new frontier come answers to questions the old paradigm did not allow to be asked. It seems to me you're posing questions that have not been allowed before a precarious position.

Karl Pribram: Let me tell you how I got into the holographic story. First, though, I want to make it clear that this is a development of theory and is fairly independent of the day today laboratory research program that engages me. The theory is largely based on the research of others. Nonetheless, because I am actively doing brain research, I have had the opportunity of at least checking for myself the essential results on which it is based.

Back in the 1950s, people dealing with the brain and those dealing with mental processes weren't together. Psychologists, who were supposed to be dealing with mental processes, by and large at that time thought “mind" was a dirty word; they were dealing with behavior. People who studied the brain were in neurophysiology. I wondered why people who were interested in behavior weren't also interested in brain function. The answer always was that we simply didn't know enough about the brain- a fair evaluation of the state of the art.

For one thing, brain science was plagued by some classic, unsolved mysteries. One was the puzzle of memory loss. More exactly, why was that any given discrete memory would not be lost after brain injury? If a person has a stroke, and half his in is destroyed, he doesn't come home and recognize only half his family. It doesn't work that way. Either memory is destroyed completely or nothing is lost. There's no correspondence between how much tissue is damaged and how much memory is lost.

Experiments had been done showing that just 2 percent of the fibers in a particular system would retain that system's functions. There's an amazing amount of redundancy in the brain. Imagine if 98 percent of your kidneys were gone, but the other 2 percent worked so well you couldn't d anything wrong at all. The brains spare reserve for memory is fantastic. And we couldn't explain it.

Thus, for over half a century, physiologists have searched for an “engram”—a change in brain cells that marks a memory trace. They've never found one. Memory seems to be distributed throughout the brain, located in no particular part.

Goleman: What are the other classic puzzles of brain science?

Pribram: One, there's the constancy problem, the question of how we can recognize an object regardless of distance or the perspective from which it is viewed. No matter where you sit in this room I can recognize you as Dan Goleman. You can sit far away or very near, and I don't look at you and think that your head has become swollen or shrunk. Your head looks a reasonable size no matter where you are. Yet the question raised is: how does a hard wired brain, in which connections between parts are fixed, allow perceptual flexibility?

Then there's a similar puzzle in the motor system, in which skills can be transferred from one limb to another...I'm right handed, but if I try, I can write with my left hand. Or even by holding a pencil in my teeth. Next time you are at the beach, try to write in the sand with your left big toe. The puzzle is that the part of the brain that controls the left hand, or the teeth, or the big toe has never written anything before. How does that particular group of brain cells process information about writing?

Something has happened that takes memory of my learning how to write and distributes it to places in the brain where it's never been called on before. There was, until .recently, no good explanation for the brain's ability to do that.

Goleman: Where have puzzles like that led you?

Pribram: Ideas started to come together in the mid 60s. A major factor was the invention of the hologram. A hologram produces a three dimensional image from a photographic film on which the interference pattern of light waves reflected from an object or scene has been recorded. When the film is illuminated, an image of the object is produced.

Goleman: What does any of this have to do with the brain?

Pribram: Sir John Eccles mentioned in an article several years ago that "synaptic potentials" -the electrical exchanges between brain cells -don't occur alone. Every nerve branches, and when the electrical message goes down the branches a ripple, or a wave front is formed. When other wave fronts come to the same, location from other directions, the wave fronts intersect and set up an interference pattern. It's somewhat like the meeting of ripples that form around two pebbles thrown into a pond.

It seemed plausible to me that if there are interfering wave fronts in the brain, those fronts might have the same properties as a hologram. Both holograms and brain tissue can be cut up without removing their image-processing capabilities. Holograms are resistant to damage- like memory in the brain. The persistent puzzle of a distributed memory might be solved. The brain had to behave, in part, like a hologram.

Goleman: The puzzle couldn't be solved without the hologram.

Pribram: Right. We'd been searching for some organizational principle that would allow for the basic facts of perceptual constancy, transfer of learning, and the elusiveness of memory in the brain. Suddenly, this principle was presented to us in the hologram.

Goleman: So that was the single organizing principle that allowed for some understanding of all those things you already knew to be both true and puzzling about the brain.

Pribram: Yes. Best of all, we didn't have to conjure up a mechanism in the brain; the hologram was there all the time in the wave front nature of brain cell connectivity. We simply hadn't had the wit to realize it. Even Eccles, who pointed to the wave phenomenon in the first place, has more recently gone back to emphasizing the nerve impulse aspects of brain functioning.

Goleman: But this is all theory. Do you have any data to back it up?

Pribram: Once we saw where to look, it became clear that one test that could be readily made was whether the behavior of single cells in, for instance, the visual system, would obey the mathematical laws that comprise a hologram. The physical hologram stores the interference patterns of light reflected from objects. The question became, therefore, whether there are cells in the brain that respond to the interference patterns of sensory input. In short, do they act as frequency analyzers -that is, do the cells resonate to different frequencies?

Goleman: Which is to say, that when the environment presents a certain frequency, a specific group of cells in the brain resonates to that frequency and not to others?

Pribram: Right. A century ago, Georg Simon Ohm suggested that brain cells in the auditory system act as frequency analyzers for sounds. Ohm is also responsible for Ohm's Law in electricity, which relates to voltage, amperage, and resistance. Hermann. von Helmholtz followed up Ohms suggestions and, for many years, the auditory system was considered to be something like a piano keyboard. Then Georg von Bekesy showed that the cochlea of the inner ear operated more along the lines of a string than a keyboard. He also showed that not only the ear, but the skin as well acts like a string: it is sensitive to vibrations and their frequencies in such away that, for example, fine tuning forks vibrating on the forearm are perceived as a simple point of vibration when their phases of vibration are properly adjusted.

In our laboratory, we showed that only a single response is produced in the brain cortex under those conditions. A further inference than can now be readily tested quantitatively is that the brain cells respond in terms of this interaction of the response and the frequencies of the tuning forks.

Goleman: How so? What are the mathematics involved?

Pribram: It's called a Fourier analysis, and is a form of calculus that transforms a complex pattern into its component sine waves. Helmholtz showed that this kind of analysis could explain the functioning of the auditory system. Then an entirely different line of research, done in Russia by N. Bernstein in the 1930s, showed that the same type of analysis fit the motor system. We didn't hear of that work until the 1960s, because Bernstein's book, The Coordination and Regulation o/ Movements [Pergamon Press), wasn't translated until 1967.

Goleman: What did Bernstein do?

Pribram: It was really fascinating. He dressed people in black leotards and took movies of them against black backgrounds. Black on black. Except that he painted white dots on their joints -elbows, knees, and so on. Then he had them do things like hammer nails, or jump up and down on platforms that were on springs. Of course, all that his movies showed were white dots moving up and down along the film, creating wave forms.

He did a frequency analysis at the wave forms. The mathematics he used were Fourier's. With that analysis, he was able to predict within a few millimeters where the next step in the sequence would fall.

Now, I read Bernstein's work and saw that he was using the same mathematics for motor activity that Ohm had used to describe the auditory system. And that was the same mathematical principle that Gabor had used to invent the hologram. So I thought, "If Bernstein can do a Fourier analysis on these movements, why can't his brain do it? And if his brain can do it, mine can, too, and perhaps this is the way everyone’s brain analyzes movements into their "frequency components.”

Goleman: So you have the same organizing principle in the auditory, somatosensory, and the somatomotor systems.

Pribram: That left the visual system. In 1968 or so, I got a note from Fergus Campbell at Cambridge University. His group had just shown that the visual system also worked as a frequency analyzer for patterns.
The significance of his discovery has still not filtered down to textbooks, which consider cells in the visual system as "feature detectors," cells that are selective of highly specific features, such as lines and comers. A classic study had shown that cells in a frog's visual system fired only in response to buglike movements. From such studies, it was concluded that all of the brain's involvement in perception was due to the fact that particular cells detected particular