THE MIND: From Memory Pills to Electronic Pleasures Beyond Sex

In all of his 35,000-year history, Homo sapiens has found it harder to fathom the depths of his mind than to unlock the secrets of his body. But the discoveries of molecular biology may well show the way to a new comprehension; they may make it possible, through genetic engineering, surgery, drug therapy and electrical stimulation, to mold not only the body but also the mind.

Man cannot wait for natural selection to change him, some scientists warn, because the process is much too slow. Yale Physiologist Jose Delgado likens the human animal to the dinosaur: insufficiently intelligent to adapt to his changing environment. Caltech Biophysicist Robert Sinsheimer calls men "victims of emotional anachronisms, of internal drives essential to survival in a primitive past, but undesirable in a civilized state." Thus, by his own efforts, man must sharpen his intellect and curb his aboriginal urges, especially his aggressiveness.

To most laymen, the idea of remaking man's mind is unthinkable; "You can't change human nature," they insist. But many scientists are convinced that the mind can be altered because it is really matter. Explains Physicist Gerald Feinberg: "What sets us apart from inanimate matter is not that we are made of different stuff, or that different physical principles determine our workings. It is rather the greater complexity of our construction and the self-awareness that this makes possible."

That self-awareness resides in the brain, the organ about which scientists have the most to learn. To Physiologist Charles Sherrington, the brain's 10 billion nerve cells were like "an enchanted loom" with "millions of flashing shuttles." For some functions, M.I.T. Professor Hans-Lukas Teuber explains, brain cells are pre-programmed with "enormous specificity of configuration, chemistry and connection." Some are sensitive only to vertical lines, others only to horizontal or oblique ones. "Each of these little creatures does his thing," Teuber says.

IN THE HOPE OF deciphering this staggering variety, hundreds of scientists, including molecular biologists, in the U.S. and abroad, are now turning to brain research. One day in the distant future, their discoveries may help man to improve his already remarkable brain--for despite its dazzling versatility and subtlety, it is not without limitation. "Computers slashing from circuit to circuit in microseconds can cope with the input and response time of dozens of human brains simultaneously," Biophysicist Sinsheimer laments. Besides, the brain can call up only a limited amount of stored information at a time to focus it on a particular problem. And while it can grasp as many as 50 bits of visual information at once, it cannot file away more than 10 of them per second for later reference.

To most scientists, this reference system, or memory, is one of the most important tools of man's intelligence. Long before the development of molecular biology, Marcel Proust pondered the mystery of memory in Remembrance of Things Past. About a man's own past, he wrote that "it is a labor in vain to attempt to recapture it: all the efforts of our intellect must prove futile. The past is hidden somewhere beyond the reach of the intellect." In Swann's Way, it was a tea-soaked petite madeleine that touched off the hero's long-forgotten childhood memories. In the scientific world, the stimulus is sometimes a surgeon's probe. Montreal Surgeon Wilder Penfield, for example, while performing operations under local anesthesia, by chance found brain sites that when stimulated electrically led one patient to hear an old tune, another to recall an exciting childhood experience in vivid detail, and still another to relive the experience of bearing her baby. Penfield's findings led some scientists to believe that the brain has indelibly recorded every sensation it has ever received and to ask how the recording was made and preserved.

Initially, some brain researchers believed that memories were stored in electrical impulses. But scientists could not comprehend how a cranial electrical system, however complex its interconnections, could accommodate the estimated million billion pieces of information that a single brain collects in a lifetime.

THEIR DOUBTS increased when they found that a trained animal generally remembered its skills despite attempts to disrupt its cerebral electrical activity by intense cold, drugs, shock or other stress; only short-term memory--of recently learned skills--was impaired. There was an obvious conclusion: while short-term memory may be partly electrical, long-term memory must be carried in something less ephemeral than an electric current.

That something, theorists believed, was chemical. Scientists had long known that chemical as well as electrical activity goes on in brain neurons: these cells carry on metabolism and protein synthesis like other body cells. Researchers soon learned that the leap of message-carrying nerve impulses across the gap between one cell and another takes place only with the help of chemical transmitter substances. One of these, acetylcholine, was promptly identified, and investigators began to look for other brain chemicals, specifically for varieties that might contain memories.

Their reasoning was that just as DNA carries genetic "memories," so other molecules might encode and carry information plucked from transient electrical impulses. Some early researchers proposed the idea of a separate brain molecule for each memory. The hypothesis of Swedish Neurobiologist Holger Hyden of the University of Goeteborg was a bit more sophisticated; he thought that RNA was the key to memory formation and was encouraged in his belief by the results of his experiments with rats. When he taught them special tasks, he discovered that the RNA had not only increased in quantity but was different in quality from ordinary RNA. In short, what Hyden did was to lay the groundwork for a molecular theory of memory.

AS HYDEN'S RAT experiments demonstrated, RNA itself does not store memories; instead, it may play an intermediary role, stimulating the brain to produce proteins that are perhaps the actual repositories of memory. In one experiment inspired by that theory, University of Michigan Biochemist Bernard Agranoff taught goldfish to swim over a barrier, then injected them with puromycin, an antibiotic that prevents protein synthesis. When the injection was given hours after learning, it had no effect, suggesting that memory proteins had already formed. Injected just before or just after training, the drug prevented learning.

Other experiments based on the RNA-protein theory may demonstrate actual chemical memory transfer. Among the most publicized are those of University of Michigan Psychologist James McConnell and Neurochemist Georges Ungar of the Baylor College of Medicine. McConnell works with planaria, or flatworms, conditioning them by electrical shock to contract when a light is flashed. He then grinds them up and feeds them to untrained worms. Once they have cannibalized their brothers, the worms learn to contract twice as fast as their predecessors. What may happen, McConnell theorizes, is that the first batch of worms form new RNA, which synthesizes new proteins containing the message that light is a signal to contract. Having consumed these memory proteins, the second group of planaria presumably do not need to manufacture so much of their own; they have swallowed memory, as it were.

Ungar's experiments are similar. Using shock, he conditions rats to shun the darkness they normally prefer, then makes a broth of their brains. This he injects into the abdominal cavities of mice, which seem to react with a parallel unnatural aversion to the dark. Moreover, the more broth Ungar injects, the faster the mice seem to learn this fear. His theory: the memory message (that darkness should be avoided) is encoded by the rats' DNA-RNA mechanism into an amino-acid chain called a peptide, a small protein that Ungar managed to isolate and then synthesize. His name for it: scotophobin, from the Greek words for "darkness" and "fear."

The experiments done by both men are hard to repeat, and investigators are still trying to decide whether the few apparent replications are sound. There is controversy, too, over the meaning of results: critics say it is hard to interpret the behavior of worms and other lower creatures objectively. Some say that Ungar may have discovered not a memory molecule but a molecule that blocked a normal response (to seek darkness) instead of teaching a new reaction (to seek light). Most investigators doubt that a single memory molecule will be found, but they believe that molecular biology will eventually reveal the secret of memory. If so, the blue-sky possibilities are limitless. It might be possible to develop "knowledge pills" that would impart instant skill in French, tennis, music or math. McConnell jokingly proposes another idea: "Why should we waste all the knowledge a distinguished professor has accumulated simply because he's reached retirement age?" His solution: the students eat the professor.

Many less frivolous proposals for improving memory and other aspects of mental life are emerging from molecular biology and genetics. It is known that genes do not cause behavior. But they influence it and set limits to physical structure, temperament, intelligence and special abilities.

Psychiatrist Alexander Thomas of New York University finds that babies show a characteristic style (easy, difficult or slow-to-warm-up) from their earliest days. While he admits that this temperament may develop in the months after birth, he does not rule out the possibility that it is inborn. Other life scientists warn that "when we strive for equality of opportunity, we must not deceive ourselves about equality of capacity." For example, it is believed that genetic influence is especially great in such areas as mathematics, music and maybe acrobatics. Unless genetic potential is tapped by the environment, it will not develop: kittens prevented from walking will not learn normal form and depth perception. Says Geneticist Joshua Lederberg: "There is no gene that can ensure the ideal development of a child's brain without reference to tender care and inspired teaching."

THIS INTERACTION between environment and heredity is one of the factors that make it so difficult to change human characteristics. Another is that nearly all behavioral traits are polygenic--dependent on several genes. But even so complex a trait as intelligence may eventually come under the control of molecular biologists. Some scientists fantasize that super-geniuses will some day be produced by increasing brain size, through either genetic manipulation or through transplantation of brain cells to newborn infants or to the fetus in the womb. (Such cells might be synthesized in the laboratory or developed by taking bits of easily accessible tissue from a contemporary Newton or Mozart and inducing them to turn into brain neurons.)

Another prospect is to alter genes so that babies will be born with rote knowledge--language skills, multiplication tables--just as birds apparently emerge from the egg with genetic programs that enable them to navigate. Some researchers hope to develop shared consciousness among several minds, thus pooling intellectual resources.

Most observers continue to feel that reining in man's aggressiveness is as important as spurring his intelligence. Harvard Neurosurgeon Vernon Mark advocates a nongenetic approach. "There are basic brain mechanisms that will stop violent behavior, and we are born with them," Mark asserts. To tap those mechanisms, scientists would like to develop an anti-aggression pill (estrogens, or female hormones, have already been used experimentally to inhibit aggressive behavior). Until they do, Mark and two Harvard colleagues--Psychiatrist Frank Ervin and Surgeon William Sweet--are fighting aggression by using surgery to destroy the damaged brain cells that sometimes cause violence in people with specific brain disease. Typical of their patients is a gifted epileptic engineer named Thomas, who used to erupt in rages so frenzied that he would hurl his children or his wife across the room. First, Mark and Ervin sent electric current into different parts of Thomas' brain; when the current sparked his rage, the doctors knew they had found the offending cells. Surgeons Mark and Sweet then destroyed them, and in the four years since, Thomas has had no violent episodes.

Physiologist Delgado has developed even more dramatic methods of aggression control in animals. In one famous experiment, he implanted electrodes in the brain of a bull bred for fierceness. Then, with only a small radio transmitter as protection, he entered the ring with the bull and stopped the angry animal in mid-charge by sending signals into what he believes was its violence-inhibiting center. Similarly, Neuroanatomist Carmine Clemente of U.C.L.A. has shocked cats into dropping rats they were about to kill. But neither man sees any early prospects for remote control of human aggression.

OTHER MENTAL problems may well succumb to molecular biology. Many therapists resist the idea that emotional problems have biochemical equivalents; yet Freud himself believed that they do and that they would one day be identified. Researchers are already convinced that schizophrenia has some genetic basis, although, as Psychologist David Rosenthal explains, it is not the disease that is inherited but a tendency to it. As a match must be struck before it will burn, so must the tendency be triggered by something in the environment. No one is yet sure whether the trigger is cultural or familial, electrical or chemical, but some investigators back the chemical theory on the ground that certain drugs enable schizophrenics to live outside institutions, at least for short periods. To date, drugs for schizophrenia have been administered on a trial-and-error basis; as molecular biologists learn more, it will become possible to use specific drugs to achieve specific ends.

FURTHER RESEARCH may provide a bonus of new genetic, chemical and electronic ways to enhance sexual pleasure. Physicist John Taylor, in fact, professes to fear that sex will become so much fun that people will want to give up practically all nonsexual activities. Author Gordon Rattray Taylor predicts that it may become possible to "buy desire," or switch it on or off at will; the playboy might opt for continuous excitement and the astronaut for freedom from sexual urges during space flight.

Unlikely as it may seem, there are researchers who claim to have discovered something better than sex. At McGill University in Canada, Psychologist James Olds used electrodes to locate specific "pleasure centers" in the brains of rats, and then allowed the animals, electrodes still in place, to stimulate themselves by pressing a lever. Given a choice, the rats preferred this new pleasure to food, water and sex. Some pressed the lever as many as 8,000 times an hour for more than a day, stopping only when they fainted from fatigue.

Such experiments lead Herman Kahn of the Hudson Institute to predict that by the year 2000, people will be able to wear chest consoles with ten levers wired to the brain's pleasure centers. Fantasies Kahn: "Any two consenting adults might play their consoles together. Just imagine all the possible combinations: 'Have you ever tried ten and five together?' couples would ask. Or, 'How about one and one?' But I don't think you should play your own console; that would be depraved."

Author Taylor, on the other hand, sees nothing wrong with solitary pleasure. Some day, he writes, a man may be able to put on a "stimulating cap" instead of a TV set, and savor a program of visual, auditory and other sensations. He and other futurists envision "experience centers" or "drug cafes" that would replace bars and coffeehouses. There, perhaps with the help of "dream machines," one might order a menu of "enhanced vision, sensory hallucinations and self-awareness." One might also be able to experience the mental states of a great man, or even of an animal. Molecular Biologist Leon Kass of the National Academy of Sciences projects a world in which man pursues only artificially induced sensation, a world in which the arts have died, books are no longer read, and human beings do not bother even to think or to govern themselves.

Some life scientists see even greater perils in man's new knowledge. "I would hate to see manipulation of genes for behavioral ends," warns Stanford Geneticist Seymour Kessler, "because as man's environment changes, and as man changes his environment, it is important to maintain flexibility." Professor Gerald McClearn of the Institute for Behavorial Genetics at the University of Colorado agrees, explaining that a gene that is considered "bad" now might become necessary for survival in the event of drastic environmental change. "It is foolhardy to eliminate genetic variability," he says. "That is our evolutionary bankroll, and we dare not squander it. Species that ran out of variability ran out of life."

Such worries are probably premature. To some experts, the more radical forms of behavior control, especially genetic modification, belong to the realm of science fiction. Yet others believe that biological predictions are always too conservative, and that man will soon proceed, and succeed, with his experiments. If he does, he must prepare himself for a social and moral revolution that would affect some of his most cherished institutions, including religion, marriage and the family. With such possibilities in mind, Nobelist George Beadle has warned that "man knows enough but is not yet wise enough to make man."

This file is automatically generated by a robot program, so reader's discretion is required.