Scientific Facts & Research On Dreams
Laboratory Testing
In laboratory testing, mentioned in almost every book about dreams, electrodes and/or sensors are placed on the face and skull to detect brain activity and eye movements during sleep. These electrodes can tell the experimenter what level of sleep the subject is in. This is how this information about brainwaves and REMs has been found. However, it was not until fairly recently, the past forty years, that any data was retrieved from these machines for they had not been invented yet. There have been multitudes of studies around dreams and sleep activity in the centuries that preceded the possibility to measure actual brain waves. The experiments and observations are far too numerous to list here in this material, but I will speak of some here.
Apparently, the first systematic effort to investigate the effect of external stimulus manipulation in dreams was carried out in 1831 by C. Girou de Buzareingues. He was a physician and a report of his work appeared in the first volume of The Lancet, a British medical journal. He played with different physical stimuli in order to induce dream events. In his first experiment, he left the back part of his head uncovered during sleep. In his dream, this showed up as an outdoor religious ceremony where members of that faith were allowed to have their heads uncovered while worshiping, which was uncommon at that time. In another dream, he left his knees uncovered and dreamed that he was in a stagecoach traveling at night, and everyone at that time knew that the knees were the first to get cold in night-time stagecoach travel. This was the first proof that external physical stimulus can induce dream events that are related in some way to the external world.
J. Borner published a book in 1855 describing how he tried to induce nightmares with external stimulus. When he experimented on himself, he buried his face in a pillow as he fell asleep, trying to induce nightmares of smothering. When he used someone else as a subject, he covered their mouth and nostrils with bedclothes, inducing dreams of not being able to breathe.
Alfred Maury, a French scientist, published a book in 1861 (expanded and revised in 1878) called Le Sommeil Et Les Reves, “Sleep & Dreams.” He carried out many experiments using himself as the subject. He had an assistant apply all sorts of physical stimuli one at a time and reported dreams that coincided with the stimuli. Another French experimenter studying sensory stimuli and dreams was Marquis Hervey Saint-Denys. He published his work on dream imagery and lucid dreams in 1967. He played with perfume scents that coincided with particular places he was familiar with. When these different perfumes were applied sporadically to his pillow at night by a servant, he dreamed of the places that the perfumes were associated with.
Taste stimuli were researched minimally during the nineteenth century, but there were experiments with this. So were visual stimuli experimented with, although it was quite difficult to introduce visual stimuli after the subject had fallen asleep. It was mostly done by giving the visual stimuli before sleep, and then the subject would dream about those visuals later.
George Trumbull Ladd did some experiments in the late 1890s around visual dreams. He theorized that the visual dreams which follow immediately after going to sleep originate predominantly from the condition of the retina, and later he proved it. He awoke from dreams, remembered the dream, and immediately examined his retinal field. He discovered that the rods and cones in the eye corresponded with what he saw in a dream and vice versa, examining the retina before he fell asleep, and then noting what his dream was.
J. Mourly Vold, a Norwegian psychologist, did extensive examination of pre-sleep visual stimuli, using himself as the primary subject. Over seven years, and three hundred exposures, he would open a packet containing a number of small objects or figures cut from cardboard, place the objects on a black or white background, and gaze at them for a specific length of time, between 2 and 10 minutes, even up to a half hour. In the subsequent dreams, the forms and sometimes the colors of the objects remained unchanged. He also experimented with restraining a limb during sleep. He noted that in the dreams the limb subjected to restraint played some important part in the dream, either of being restrained or being used in an exaggerated way.
There were many experimenters with physical external stimuli and dreams, but for the sake of this course, we will not go into every single one. In fact, all sorts of experiments were done, from exploring the power of suggestion to planting desires in dreams. Multitudes of psychological experiments were done and many dreams were recorded. However, the most important information about dreams and sleep patterns came with the invention of the electroencephalogram (EEG). This new technology showed the brain’s electrical activity during sleep and wakefulness and was a godsend to those who were experimenting with sleep patterns. It solved many mysteries! The EEG was invented in 1930, and by the 1940’s vast amounts of data had been gathered about the patterns observed during sleep. Very few experimented with dreams, for at that time dreams were still considered unimportant and not worthy of scientific study. Dream research did not really begin until the 1950’s and 1960’s.
The first true dream research using the EEG began with Nathaniel Kleitman, a physiologist at the University of Chicago, and Eugene Aserinsky, one of the medical students working in Kleitman’s laboratory. Aserinsky, observing the sleeping behavior of infants in their cribs, noted that there were periods when the baby’s eyes were moving for certain amounts of time. He and Kleitman monitored the duration of these movements by attaching electrodes around the baby’s eyes. Then they wondered if adults had these eye movements in the same patterns and durations. They discovered that they did. They named these movements Rapid Eye Movements (REMs). They decided to wake the sleeper during these movements in order to find out if the subject was dreaming at that time. Out of 27 of these awakenings, 20 detailed descriptions of dreams were recalled. They also woke people when these movements were not present 23 times. For 19 of these occasions, no dream was reported.
Aserinsky and Kleitman also recorded the brainwaves, heart rates and respiration patterns present during these REM periods. When they looked at all the data, they realized that during REM periods, there was a higher heart and respiration rate, and an EEG pattern showing a different electrical activity from the more passive periods of sleep. They published a short two page summary of their findings in the journal Science on September 4, 1953. That was the first serious research done on dreams up to that point. What came afterwards was an outpouring of research by many inspired researchers. Aserinsky and Kleitman published a much more detailed description of their investigation in 1955.
Aserinsky left the university after he finished his doctoral dissertation and another student took his place. His name was Dement and he was primarily focused on psychiatry. He monitored only mental patients at first. He monitored them with the EEG machine quite differently than his predecessor, however. He turned the machine on for one minute out of every five instead of occasionally during the night, as was done before. This extra monitoring proved to be of utmost importance in discovering more about sleep patterns and dreaming. Dement noted that REM activity always came after a frequency of about ten cycles per second was being recorded.
Dement published a landmark article in 1957 with Kleitman. They left the machine on all night, and the results were incredible. This created a foundation for all the dream experimentation that came after that. They discovered that REM periods occurred every 92 minutes. Subjects were awakened during REM states and NREM (non-REM) states alike. During the REM periods, subjects reported dreams 80% of the time. When awakened during NREM periods, subjects only reported dreams by 7% of the time. REM awakenings made within 8 minutes after the end of an REM period, dream recall was 29%. After 8 minutes, the recall rate was only 5%. This indicates that dream recall fades rapidly after the REM period. Awakenings were also conducted during REM periods, from 5 to 15 minutes of REM, to determine if the length of the dream had any connection to how long the REM state was going on. It was determined that the length of time the REM state took and the length of the dream were associated with each other.
They published yet another article in 1957 where subjects were monitored uninterrupted just to see what patterns were noticeable. They discovered that in a six hour period of sleep, four REM periods usually happened between one and seventy two minutes. The average amount of sleep time spent in REM activity in a six hour sleep would average 18%. This percentage was higher if an eight hour period of sleep were used. They discovered that REM periods became progressively longer as the night wore on and the REM activity happened more often closer to morning and the more sleep time, the higher the percentage of REM time.
Much experimentation was done on dreams after this, and the terminology began to get mixed up. It was not until 1968 when a committee of experienced sleep researchers got together and devised a standard terminology for measuring sleep patterns in A Manual Of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects