AS EARLY AS THE MID-1920s A SWISS PHYSIOLOGIST, WALTER
Hess, had begun investigating the effects of electrically stimu-lating certain areas deep inside the brains of cats. Surgically implanting thin electrical wires that were completely insulated except at their very tips, Hess found that extremely mild elec-trical currents could cause a cat immediately to undergo dra-matic changes in behavior - stimulation of one area would cause the cat to fly into a spitting, howling rage; current direc-ted to another nearby area triggered fear and terror. Hess found that any behavior that appeared to be the result of pow-erful emotion could be triggered if the right area of the brain was stimulated. But was what the cat was experiencing true emotion, or simply some mechanical response? Was it really possible that emotions themselves - those things we often be-lieve are most truly us, our loves, fears, dreams - could be triggered as automatically as causing our knee to jerk by strik-ing it with a small rubber mallet? Were we little more than robots, susceptible to emotional changes at the twist of a knob sending electrical current into parts of our mental machine?
Dr. Wilder Penfield's discovery that electrical stimulation of the human brain evoked perfect memories of long-forgotten events seemed to indicate that much of what we experience, even material that we have never been conscious of exper-iencing, is stored away in the brain in such a way that it can be precisely recalled (or called into consciousness for the first time ever) at any future time. Penfield concluded, "A synaptic facilitation is established by each original experience. If so, that permanent facilitation could guide a subsequent stream of neuronal impulses activated by the current of the electrode even years later."261
If we understand Penfield's idea of "synaptic facilitation"
to be taking place on the level of thousands or millions of 122
WE SING THE MIND ELECTRIC, PART ONE: TENS
interconnected neurons, then clearly the contents of our brains - memories, emotions, images, ideas - are stored away in the form of vast but quite distinct neural networks connected by neuronal impulses. The networks for similar ideas or perceptions - say, the subtle difference in taste among wines of the same type - would be made up of almost all the same neurons, except for a few thousand here or there that would distinguish one wine from another. This would explain why a simple low-impulse electrical current applied to one highly specific group of neurons could, by "synaptic faci-litation," activate a richly intertwined group of memories, perceptions, sensations, in the same way a simple sniff of a beloved wine can light up an entire neural memory network in a wine connoisseur.
While Penfield was stimulating various areas of the brain and trying to map out which areas seemed to control language, memory, speech, and specific emotions and sensations, an-other scientist, James Olds, with associate Peter Milner, was taking a different approach. Implanting electrodes in a certain area of the brains of rats, he found that electrical stimulation seemed to cause the rats to feel intense pleasure. Electrodes implanted in slightly different spots seemed to cause rats to experience rage, fear, and distinct displeasure when those centers were stimulated. What would happen, Olds wondered, if rats were permitted to trigger their own pleasure or "reward"
centers?
After implanting the electrodes, Olds attached the wires to a device that allowed the rats to turn on the juice and give themselves a short jolt of joy by pressing a foot pedal. The rats were ecstatic, reveling in a tireless orgy of self-stimula-tion. They attacked the foot pedals with such hoggish verve they seemed possessed, pressing the levers as often as five thousand times an hour, and gladly underwent all sorts of ar-duous experiences, like crossing painfully shocking electrical grids, for the chance to press the pleasure pedal. Obsessed with pleasure, they would pass up food, drink, and rest, and literally starve themselves to death, stimulating themselves
123
MEGABRAIN
LEARNING TO PUSH THE PLEASURE BUTTONS
AS EARLY AS THE MID-1920s A SWISS PHYSIOLOGIST, WALTER
Hess, had begun investigating the effects of electrically stimu-lating certain areas deep inside the brains of cats. Surgically implanting thin electrical wires that were completely insulated except at their very tips, Hess found that extremely mild elec-trical currents could cause a cat immediately to undergo dra-matic changes in behavior - stimulation of one area would cause the cat to fly into a spitting, howling rage; current direc-ted to another nearby area triggered fear and terror. Hess found that any behavior that appeared to be the result of pow-erful emotion could be triggered if the right area of the brain was stimulated. But was what the cat was experiencing true emotion, or simply some mechanical response? Was it really possible that emotions themselves - those things we often be-lieve are most truly us, our loves, fears, dreams - could be triggered as automatically as causing our knee to jerk by strik-ing it with a small rubber mallet? Were we little more than robots, susceptible to emotional changes at the twist of a knob sending electrical current into parts of our mental machine?
Dr. Wilder Penfield's discovery that electrical stimulation of the human brain evoked perfect memories of long-forgotten events seemed to indicate that much of what we experience, even material that we have never been conscious of exper-iencing, is stored away in the brain in such a way that it can be precisely recalled (or called into consciousness for the first time ever) at any future time. Penfield concluded, "A synaptic facilitation is established by each original experience. If so, that permanent facilitation could guide a subsequent stream of neuronal impulses activated by the current of the electrode even years later."261
If we understand Penfield's idea of "synaptic facilitation"
to be taking place on the level of thousands or millions of 122
WE SING THE MIND ELECTRIC, PART ONE: TENS
interconnected neurons, then clearly the contents of our brains - memories, emotions, images, ideas - are stored away in the form of vast but quite distinct neural networks connected by neuronal impulses. The networks for similar ideas or perceptions - say, the subtle difference in taste among wines of the same type - would be made up of almost all the same neurons, except for a few thousand here or there that would distinguish one wine from another. This would explain why a simple low-impulse electrical current applied to one highly specific group of neurons could, by "synaptic faci-litation," activate a richly intertwined group of memories, perceptions, sensations, in the same way a simple sniff of a beloved wine can light up an entire neural memory network in a wine connoisseur.
While Penfield was stimulating various areas of the brain and trying to map out which areas seemed to control language, memory, speech, and specific emotions and sensations, an-other scientist, James Olds, with associate Peter Milner, was taking a different approach. Implanting electrodes in a certain area of the brains of rats, he found that electrical stimulation seemed to cause the rats to feel intense pleasure. Electrodes implanted in slightly different spots seemed to cause rats to experience rage, fear, and distinct displeasure when those centers were stimulated. What would happen, Olds wondered, if rats were permitted to trigger their own pleasure or "reward"
centers?
After implanting the electrodes, Olds attached the wires to a device that allowed the rats to turn on the juice and give themselves a short jolt of joy by pressing a foot pedal. The rats were ecstatic, reveling in a tireless orgy of self-stimula-tion. They attacked the foot pedals with such hoggish verve they seemed possessed, pressing the levers as often as five thousand times an hour, and gladly underwent all sorts of ar-duous experiences, like crossing painfully shocking electrical grids, for the chance to press the pleasure pedal. Obsessed with pleasure, they would pass up food, drink, and rest, and literally starve themselves to death, stimulating themselves
123
MEGABRAIN
until they passed out with exhaustion. And when they awoke they would begin again.*245
Everyone was fascinated with Olds's research. The prob-lem was that none of the scientists could understand the mech-anism at work. What could be so pleasurable about a jolt of electricity in the brain? The scientists were to remain baffled by this pleasure effect for many years.
However, while the cause remained a mystery, many scien-tists of the 1950s were beginning to suspect that electrical stimulation of the brain was perhaps the most powerful tech-nique for altering consciousness and behavior that had been discovered. Dr. Robert Heath, head of the neurology/psychia-try department at Tulane University School of Medicine, cre-ated a firestorm of controversy when in 1950 he became the first scientist to implant electrodes in the human brain and leave them in place for long periods. He used such electrodes both to record and stimulate: he made recordings of the EEG in the depths of the brains of people who were experiencing rage, seizures, hallucinations, sexual arousal; and by stimulat-ing various sites in the subjects' brains he found he could trigger outbursts of joy, pleasure, fear.
His patients were all sufferers of seemingly incurable men-tal diseases - severe schizophrenics, homicidal psychotics, suicidal depressives - and Heath's research forced him to the conclusion that the unifying characteristic of all these mental disorders is that the subject has "an imbalance between pleas-ure and pain," with little or no ability to experience pleaspleas-ure, and conversely a greatly exaggerated ability to experience pain, anguish, loneliness. These severe psychotics, Heath re-alized, were like Olds's rats being constantly tormented by electrodes stimulating their pain/displeasure centers. Why not actually implant working electrodes in their pleasure centers
*Interestingly, the wired-up rats turned into extraordinary learners. Mazes that took ordinary rats long periods of trial and error to learn the wired rats learned with astonishing speed. They also remembered longer and more clearly than did the nonstimulated rats. Curious. It also seemed as if the electrical stimulation itself was making the rats smarter. But of course, as all brain scientists knew in those days, that was impossible We will return to this curious side effect later.
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instead, and give them the pleasure they'd never been able to experience?
Heath began implanting electrodes in patients' brains, and allowing them to self-stimulate themselves to produce pleas-ure. He found that many of his most violent or intractable cases experienced immediate transformations and recoveries.
Some of his cases he provided with small control boxes so they could stimulate their pleasure centers at will. Not only did such self-stimulation make depressions, delusions, violent rages, hallucinations, and some epileptic seizures go away, it also alleviated pain in subjects who had experienced chronic, intractable pain for many years. According to Heath, "Each system of the brain (pleasure and pain) is seemingly capable of overwhelming or inhibiting the other. Activation of the pleasure system by electrical stimulation or by administration of drugs eliminates signs and symptoms of emotional or physi-cal pain, or both, and obliterates changes or recordings asso-ciated with the painful state."276
In the 1950s the reigning technique for approaching mental disorders was psychoanalysis. The great master was Freud, with his message that psychological problems could be traced to childhood traumas and unresolved complexes. Heath burst into this world like a Mad Hatter at a staid tea party. "I never thought that mental disease was anything other than biologi-cal," he has said. At that time such thoughts were pure here-say, reductionism of the worst sort. The Freudians had apparently forgotten that the master himself had written, "In view of the intimate connection between things physical and mental, we may look forward to a day when paths of knowl-edge will be opened up leading from organic biology and chemistry to the field of neurotic phenomena."
Through the 1960s and early 1970s, scientists continued to experiment with electrical brain stimulation. It was discovered that it was possible to alter the electrical activity of the brain and nervous system without direct stimulation (i.e., by im-planted electrodes), but by applying the electrical current at the skin surface. This technique of transcutaneous nerve stim-ulation (TENS) was found to be particularly effective in
re-125
MEGABRAIN
until they passed out with exhaustion. And when they awoke they would begin again.*245
Everyone was fascinated with Olds's research. The prob-lem was that none of the scientists could understand the mech-anism at work. What could be so pleasurable about a jolt of electricity in the brain? The scientists were to remain baffled by this pleasure effect for many years.
However, while the cause remained a mystery, many scien-tists of the 1950s were beginning to suspect that electrical stimulation of the brain was perhaps the most powerful tech-nique for altering consciousness and behavior that had been discovered. Dr. Robert Heath, head of the neurology/psychia-try department at Tulane University School of Medicine, cre-ated a firestorm of controversy when in 1950 he became the first scientist to implant electrodes in the human brain and leave them in place for long periods. He used such electrodes both to record and stimulate: he made recordings of the EEG in the depths of the brains of people who were experiencing rage, seizures, hallucinations, sexual arousal; and by stimulat-ing various sites in the subjects' brains he found he could trigger outbursts of joy, pleasure, fear.
His patients were all sufferers of seemingly incurable men-tal diseases - severe schizophrenics, homicidal psychotics, suicidal depressives - and Heath's research forced him to the conclusion that the unifying characteristic of all these mental disorders is that the subject has "an imbalance between pleas-ure and pain," with little or no ability to experience pleaspleas-ure, and conversely a greatly exaggerated ability to experience pain, anguish, loneliness. These severe psychotics, Heath re-alized, were like Olds's rats being constantly tormented by electrodes stimulating their pain/displeasure centers. Why not actually implant working electrodes in their pleasure centers
*Interestingly, the wired-up rats turned into extraordinary learners. Mazes that took ordinary rats long periods of trial and error to learn the wired rats learned with astonishing speed. They also remembered longer and more clearly than did the nonstimulated rats. Curious. It also seemed as if the electrical stimulation itself was making the rats smarter. But of course, as all brain scientists knew in those days, that was impossible We will return to this curious side effect later.
124
WE SING THE MIND ELECTRIC, PART ONE: TENS
instead, and give them the pleasure they'd never been able to experience?
Heath began implanting electrodes in patients' brains, and allowing them to self-stimulate themselves to produce pleas-ure. He found that many of his most violent or intractable cases experienced immediate transformations and recoveries.
Some of his cases he provided with small control boxes so they could stimulate their pleasure centers at will. Not only did such self-stimulation make depressions, delusions, violent rages, hallucinations, and some epileptic seizures go away, it also alleviated pain in subjects who had experienced chronic, intractable pain for many years. According to Heath, "Each system of the brain (pleasure and pain) is seemingly capable of overwhelming or inhibiting the other. Activation of the pleasure system by electrical stimulation or by administration of drugs eliminates signs and symptoms of emotional or physi-cal pain, or both, and obliterates changes or recordings asso-ciated with the painful state."276
In the 1950s the reigning technique for approaching mental disorders was psychoanalysis. The great master was Freud, with his message that psychological problems could be traced to childhood traumas and unresolved complexes. Heath burst into this world like a Mad Hatter at a staid tea party. "I never thought that mental disease was anything other than biologi-cal," he has said. At that time such thoughts were pure here-say, reductionism of the worst sort. The Freudians had apparently forgotten that the master himself had written, "In view of the intimate connection between things physical and mental, we may look forward to a day when paths of knowl-edge will be opened up leading from organic biology and chemistry to the field of neurotic phenomena."
Through the 1960s and early 1970s, scientists continued to experiment with electrical brain stimulation. It was discovered that it was possible to alter the electrical activity of the brain and nervous system without direct stimulation (i.e., by im-planted electrodes), but by applying the electrical current at the skin surface. This technique of transcutaneous nerve stim-ulation (TENS) was found to be particularly effective in
re-125
MEGABRAIN
ducing pain, and by,the mid-1970s everyone from doctors to dentists to sports trainers was using TENS devices to alleviate pain. Things had come a long way from the ancient Egyptians and Greeks with their electrical-eel cures. Or had they? Scri-bonius knew that the electrical torpedo ray would relieve pain, though he didn't know how. And in the mid-1970s, millions were using TENS devices for pain relief. Yet despite extensive research, no one was able to explain exactly how electricity had such a dramatic pain-reducing effect.
ELECTRICALLY ACTIVATED KEYS TO PARADISE
THEN IN THE MID-1970S SCIENTISTS DISCOVERED THE Exis-tence of endorphins, the body's own opiates. We all know that opiates, such as heroin, morphine, and opium, have profound effects on the human brain, not only relieving pain but pro-ducing such euphoria that millions of humans have become addicted to them, destroying themselves for these precious pleasurable substances. The reason for this fatal attraction be-tween humans and opiates, it seems, is based on a bizarre coincidence: the molecules of opiates have the same shape as a group of molecules naturally produced in our bodies and brains, those now-famous endorphins (from endogenous mor-phine, morphine produced within ourselves). These neuro-chemicals, dubbed the "keys to paradise," serve a variety of purposes in our bodies, including reducing pain, alleviating stress, giving us pleasure, rewarding behavior that is condu-cive to our survival, enhancing or suppressing memories, and determining what information we allow into our brains. When triggered by some appropriate stimulus, our brains secrete en-dorphins. They then flow from neuron to neuron, like neuro-transmitters, but also sweep through our nervous system, like hormones. In the brain, they are accepted by appropriate
THEN IN THE MID-1970S SCIENTISTS DISCOVERED THE Exis-tence of endorphins, the body's own opiates. We all know that opiates, such as heroin, morphine, and opium, have profound effects on the human brain, not only relieving pain but pro-ducing such euphoria that millions of humans have become addicted to them, destroying themselves for these precious pleasurable substances. The reason for this fatal attraction be-tween humans and opiates, it seems, is based on a bizarre coincidence: the molecules of opiates have the same shape as a group of molecules naturally produced in our bodies and brains, those now-famous endorphins (from endogenous mor-phine, morphine produced within ourselves). These neuro-chemicals, dubbed the "keys to paradise," serve a variety of purposes in our bodies, including reducing pain, alleviating stress, giving us pleasure, rewarding behavior that is condu-cive to our survival, enhancing or suppressing memories, and determining what information we allow into our brains. When triggered by some appropriate stimulus, our brains secrete en-dorphins. They then flow from neuron to neuron, like neuro-transmitters, but also sweep through our nervous system, like hormones. In the brain, they are accepted by appropriate