AMAZING Electrical Tests SHOW What Happens When You Think (May, 1936)
AMAZING Electrical Tests SHOW What Happens When You Think
By Edwin Teale
PIONEERS in an amazing new field of research recently traveled to the Loomis Laboratories, Tuxedo Park, N. Y., for the first meeting of its kind in America. The sixty scientists who compared notes are “brain-wave” experts, students of minute, telltale pulsations of electric current that come from the billions of cells in the human brain.
With supersensitive electricity-recording instruments, able to register less than a millionth of a volt of current, they are discovering curious facts about our brains and how they work. Already, these scientists have achieved such exciting feats as “photographing a dream,” watching the electrical pattern made by brain cells in solving a mathematical problem, and witnessing an “electrical storm,” piling up in the brain of an epileptic. By discovering rhythms in the varying strengths of these tiny currents, they are working toward a radically new technique in detecting and diagnosing various ailments of the brain.
The first man to tap this feeble flow of power was the German scientist, Fleischle von Marxow. In 1890, with crude and relatively insensitive apparatus, he detected faint electrical impulses passing through the skulls of animals.
For generations before, physiologists had known that tiny currents of electricity accompany the functioning of many parts of the body. If you wink your eye, clench your jaws, take a deep breathâ€” each action produces its minute flow of electricity. Time after time, laboratory tests have revealed the connection between electricity and animal life.
When the Nobel Prize winner, Dr. E. D. Adrian, of Cambridge University, England, connected the nerve of a cat’s foot to an amplifying set and a galvanometer, an instrument which determines the intensity of an electric current, he found that electricity flowed along the nerve every time he flexed the animal’s toe. At Princeton University, the American scientists E. G. Wever and C. W. Bray, performed an even more spectacular test. Disconnecting the auditory nerve of a rabbit from the brain, they attached it by means of electrodes to vacuum tubes and a telephone. Words spoken into the rabbit’s ear could be heard over the telephone, proving that ears literally are microphones, turning sound oscillations into electrical impulses. In another laboratory, scientists discovered that the beating heart of an embryo chicken, barely formed within its shell, gave off sufficient current to influence a sensitive galvanometer.
But, most striking of all is the record of a moving mirror in an English apparatus. The heart of a frog was removed and connected to a reflecting galvanometer in which electrical impulses tilted a tiny mirror to deflect a beam of light. Even after all visible signs of life had left the organ, regular pulsations of electric current continued to swing the mirror of the instrument. Hour after hour, in the stillness of the darkened room, the spot of light reflected on the wall maintained its weird and silent oscillations, recording the electric beating of a heart apparently dead!
BY REGISTERING the changes in electric current produced by the human heart on a graph called an electrocardiogram, specialists now diagnose heart ailments. Variations in the curves on these graphs indicate the sources of trouble and aid in prescribing treatment.
For decades after Von Marxow’s discovery of brain waves, research in this field awaited new and better equipment. The development of the radio brought it. Vacuum tubes, able to amplify feeble electrical impulses hundreds of thousands of times, make present-day experiments possible.
In 1929, Hans Berger, at the University of Jena, Germany, began the first extensive series of brain-wave investigations. It was the work of this pioneer that led science into a fertile field of research. He carried on his tests under a wide variety of conditions, with subjects hot and cold, relaxed and excited, asleep and under anesthetics. In operating rooms, he placed his electrodes directly on the brain through openings in the skull. He tested scholars and feeble-minded children and, in one experiment, he watched fluctuations in current as a person, deprived of air, lapsed into unconsciousness.
In the United States, such scientists as Hallowell Davis, E. L. Garceau, and A. J. Derbyshire of Harvard, Leonard Carmichael and H. H. Jasper of Brown University, Alfred L. Loomis and Garret Hobart of the Loomis Laboratories, E. Newton Harvey of Princeton, and Louis W. Max, of New York University, have pushed ahead with further researches.
Recently, I spent an afternoon watching Dr. Max at work. Imagine yourself behind the scenes in his basement brain-wave laboratory. Assistants are busy checking batteries, warming electrodes, loading the recording camera. Sometimes, it takes as long as two hours to warm up and adjust the delicate instruments and get everything in readiness for a test.
The subject takes his place on a special cot in a screened-off portion of the laboratory. One arm is carefully scrubbed with soap and water, then washed with alcohol, and finally rubbed with ether to remove all skin oils. Then, strips of cloth, saturated with a salt solution, are wound about the arm to keep the electrodes pressed against the skin at the wrist and on the forearm. A white turban, suggesting a nightcap, contains the silver head electrodes and keeps them in contact with the scalp. At present, Dr. Max is carrying on a fascinating series of experiments in connection with deaf-mutes. He has discovered that they literally “think with their hands.” That is, electrical activity in the brain is paralleled by similar activity in the hands, even when the latter fail to show the slightest movement. In subjects having the faculty of speech, this is not true. Instead, they appear to have parallel electrical activity in brain and tongue. This brings up a startling question: Do we think with our brains or with our whole bodies? It is this line of research Dr. Max is now pursuing, and his electrical records indicate that we really think with our whole bodies!
During one of his early experiments, a curious succession of electrical impulses began coming through his instruments. Puzzled, he clipped earphones into the circuit and discovered he was picking up a short-wave broadcast! The horizontal body of the subject was acting as the antenna. Now, subjects are shielded by a coffinlike framework, covered with copper screen, which is placed over them on the cot. When two assistants have finished lowering this framework into place, the lights snap off. You follow Dr. Max into the dimly lighted instrument room beyond the partition. The faint impulses being picked up by the electrodes run through shielded cables into great, boxed-in amplifiers at the far end of the instrument chamber. There, just as your radio amplifies tiny waves caught by the antenna, rows of vacuum tubes magnify the minute electrical impulses coming from the brain and arm of the subject so that they will actuate recording apparatus.
THE impulses then flow on into two Einthoven oscillographs, super-sensitive galvanometers with gold-plated quartz filaments less than a thousandth of an inch thick. These filaments are suspended in magnetic fields produced by two giant, horseshoe-shaped electromagnets. The amplified electrical impulses coming from the brain and arm of the subject flow through the fine quartz threads and cause them to vibrate according to the strength of the current.
It is the shadows of these vibrating strings cast by powerful projection lamps that write the records of the varying electric currents on the film of the recording camera. Just now, the shutter of the camera is closed and the two fine, dark lines pulsate back and forth on a ruled observing screen. The camera, behind the screen, can be set in action in an instant to make a permanent record of any portion of the test.
For nearly twenty minutes, the dark lines vibrate in erratic fashion. Then the brain line settles into a steady rhythmic fluctuation. The subject is asleep. Slumber is usually chosen for tests because then the brain and body conditions are most constant.
On more than a score of occasions, Dr. Max has recorded dreams on his strips of films. In one, the subject imagined himself at Coney Island and in another he was engaged in a fist fight at a barbecue. These wavy lines form the world’s first picture of a dream. And they shed light on a long-debated question in psychology: How long does a dream last?
This work interested me particularly because of an experience I had some years ago. I dreamed of wrestling with a burglar in a dark kitchen and knocking a tin pan from a hook in the course of the struggle. I awoke with the sound of a pan striking the floor reverberating in my ears. A friend of mine, a Harvard psychologist, later told me that I had dreamed the whole struggle in a flash, during the instant I was waking up after hearing the pan accidentally fall from the hook. Dreams, psychologists then agreed, were compressed into a second or two of time. Now, Dr. Max’s records of electrical activity in the brain indicate that dreams may last for two and a half minutes or more.
How do scientists know the pulsations they get really come from the brain?
There are several reasons, Dr. Max explains. In the first place, the form and rhythm of pulsations from muscles and from the brain are noticeably different to the eye of the expert. Furthermore, when Berger, the German experimenter, placed his electrodes directly on the brain in an operating room, he got stronger currents than when they were on the outside of the skull. This would not have been so if the current came from anywhere except the brain itself.
During his researches, Berger also discovered that brain waves fall into two general groups, the alpha rhythm, with approximately ten fluctuations a second, and the beta rhythm, with twenty or more a second. The character of these electrical pulsations remains about the same for a given subject day after day. Eventually, the German scientist hopes to discover the normal wave, just as heart specialists have done in the case of the electrocardiogram, thus enabling him to diagnose brain ills electrically.
Along this line, research men at Harvard have found that epilepsy can be detected through the abnormal brain waves given off by the afflicted person. Seizures, their tests indicate, are nerve storms which result in a great piling up of electrical charges. During an epileptic fit, the flow of electricity from the brain increases 3,000 percent over that given off when the brain is relaxed and normal.
When a person faints, on the other hand, brain waves slow down to from three to five a second. But, the voltage rises to more than double the normal level. In Dr. Max’s laboratory, it has been discovered that the harder the brain works the more electricity is recorded from the arms of his deaf-mute subjects. He has found that doing a difficult mathematical problem will produce more of this body current than doing an easy one and that memorizing a sentence results in a greater output of electrical impulses than simply reading it.
So far, the tests show that the more intelligent you are, the less body current you generate during thinking. Also, they show that when you are chilly, the voltage is greater than when you are comfortably warm.
At points of special interest during the test, Dr. Max opens the shutter of his recording camera and the shadows of the pulsating quartz filaments leave their permanent zigzag record on the sensitive film. By studying hundreds of such records, the scientist hopes to find the solution to another physiological riddle: How deep is a deep sleep? From his researches, he expects to discover some electrical yardstick by means of which he can measure the degrees of slumber.
THERE are probably less than half a dozen similar laboratories in the country. At the Loomis Laboratories, Tuxedo Park, N. Y., you see the most elaborate scientific equipment of all for the study of these mysterious currents. There, instead of a recording camera and vibrating quartz filaments you find a great horizontal drum, eight feet long and forty-four inches in circumference, capable of holding a continuous, eight-hour record.
In the room where the subject sleeps, a sensitive microphone picks up each sound and a photo-electric, or light-sensitive, cell records every movement on the bed. Amplified current, coming from the electrodes held in place against the sleeper’s scalp, actuates twin highspeed, siphon recorders, hollow pens with a continuous flow of ink, which trace their wavy lines a fifth of an inch apart on paper attached to the revolving drum.
One line is in red ink, the other in green. The red line shows each heartbeat, each respiration, each movement of the subject on the bed, while the green line records the fluctuation of electric current from the brain. The two pens advance along the drum at the rate of one foot an hour. Three ratchet devices sum up the heartbeats, the respirations, and the bed movements every time the drum completes a revolution, marking the rate per minute on the paper. As the drum is driven by a constant-speed motor and acts as its own clock, electric contacts enable the scientists to send a given stimulus to a sleeper at regular intervals and to note the effect on the currents from the brain.
The finished graph produced by this method is a sheet forty-four inches wide and eight feet long. To simplify studying the huge record-sheet, Dr. Loomis and his associates view it first through a red glass, so that only the green lines are visible, and then through a green glass, so only the red lines show.
FROM such study of these scientific hieroglyphics, Dr. Loomis believes he has discovered six types of brain waves, each recognizable through the spiked or balled character of the sharply zigzagging lines. During certain hours of the night, he reports, there are mysterious bursts of electrical activity in the brain. These bursts appear in trains and last from five to twelve seconds.
One curious thing observed at Tuxedo Park is that steady snoring has no effect upon the electric current flowing from the brain, but an isolated snore, apparently startling the sleeper, starts a train of increased pulsations. Many sounds, such as the distant slamming of a door, will cause increased electrical activity in the brain cells when a person is asleep but will not do so when he is awake.
Little by little, laboratory explorers are feeling their way into this new realm of science. The researches carried on thus far, fascinating as they have proved, merely scratch the surface of the possibilities ahead.