Sensory deprivation and hallucinations
Type of Spiritual Experience
Dr Jack Vernon undertook a series of controlled experiments in a specially made ‘dark room’. A large soft king sized bed was provided to minimise the sensation of touch. Clearly this was one sense not eliminated, but as this sensation did not change throughout the experiment as most subjects tended to lie fairly still, there was in a sense no stimulus, as generally our nerves measure change of stimulus, rather than the continual monitoring of a uniform stimulus.
The dark room was completely sound proofed and completely dark, however, the research subjects knew that there was a toilet they could go to in the room. Taste sensation was not eliminated as the subjects were provided with a cold box with food [mostly sandwiches and soup]. There was also a ‘panic button’ provided, so that if they felt they could endure no more they could ask to be removed, although the door was not locked and in fact they could walk out at any time. The research subjects were nearly all male and post graduate students at the university [Princeton].
“Our subjects were volunteers who could leave the chamber at will. They underwent no physical hardships, the period of confinement was short and the experience not fear arousing”
In effect, the experiments measured benign partial sensory deprivation.
A description of the experience
Inside the Black Room – Dr Jack Vernon
"I guess I was in there about a day or so before you opened the observation window. I wondered why you waited so long to observe me."
This statement was the first example of a hallucination experienced by any of our S.D. subjects. We had expected S.D. to produce hallucinations, as the group working in Dr. Hebb’s laboratory at McGill University had reported such occurrences. In fact twenty-five of twenty-nine subjects they used reported some form of them………………..
In one of their studies fourteen subjects reported a variety of visual experiences as having occurred during their confinement. The simple form of visual experience was shifts from light to dark, dots, lines, or simple geometric patterns. All fourteen subjects reported “seeing" such things. A more complex visual experience was seeing something like “wallpaper patterns," which eleven subjects reported. Isolated figures and objects that had no backgrounds were reported by seven of the fourteen. Only three reported integrated complex scenes that were similar to a “cartoon."
Some of these hallucinations were tilted at an angle and even, in a few cases, inverted. Some subjects experienced hallucinations other than visual ones.
One subject reported hearing people speaking, and another repeatedly heard a music box. There were also tactual hallucinations. One subject “saw" a tiny ship firing pellets and felt them strike his arm. Another “saw" a doorknob and reached out for it, only to receive a mild electric shock in his fingers. Thus he also hallucinated the feeling of the doorknob.
Our first SD study, which utilised only 4 subjects, did not reveal any visual hallucinations. …… We decided that our study was at fault…. We changed our conditions so that no light occurred in the cubicle. The subjects had everything in the cubicle they needed except toilet facilities, and when that need arose they were blindfolded and let out of the cubicle to a toilet. Under these conditions we used nine subjects. Six of these experienced a total of fifteen hallucinations.
……. We thought that our subjects might be afraid to report any such "damaging" testimony to us. As it turned out, our fears were ungrounded. To a man, if our subjects hallucinated they volunteered the information before we questioned them, and they spoke freely. They were not only unembarrassed about their hallucinations, they readily admitted enjoying them as welcome relief. When their perceptions disappeared or faded away, most subjects tried unsuccessfully to bring them back.
…………One subject, …., saw a window. The window was easily reducible to a rectangle containing a series of squares. It is interesting in this particular case that our subject saw what he expected-that we would look in on him-and he was surprised only that we had not done it earlier in his confinement.
Another subject saw a ventilator in the ceiling.
Once again here is the element of expectation, for the ventilator, as he drew it, was composed of a large, narrow rectangle filled with many smaller rectangles.
One subject reported seeing a piece of soundproofing hanging in front of him. When asked to draw it he drew a net composed of small diamond shapes. He thought that a sheet of the soundproofing had come loose from the ceiling and was hanging down in front of him.
Another subject reported seeing a dime on the floor.
At first he thought that an accidental light leak had developed in the room and that the light was being reflected by the dime. As he reached for it it disappeared, much to his disappointment. When the coin reappeared to him later, he resisted the temptation to pick it up, hoping to make it last longer. To his sorrow it once again faded quickly……………………
Drs. Zubeck, Pushkar, Sansom, Gowing, and Prysiazniuk, working at the University of Manitoba, used conditions similar to some used by us. They confined sixteen subjects in a dark, soundproof chamber for periods of one week each. They found eleven of the sixteen experiencing some sort of hallucinatory activity. It is notable that these investigators used the criteria for hallucinations which we had insisted upon in a publication with which they were familiar. They also indicate, and this may be very significant, that their subjects did not usually hallucinate before the third day of sensory deprivation.
Most of their subjects had Type 1 hallucinations, a few Type 2, and only two occasions of Type 3. Both of the Type 3 hallucinations occurred during the sixth day of S.D. These investigators also found a number of very realistic auditory hallucinations, such as “howling dogs", "alarm clocks", “typewriter", "whistle,", “dripping water" etc. Twelve of their subjects were male, ten of whom had hallucinations, while only one of the four female subjects had hallucinations…………
Many if not most of our subjects reported that during S.D. they heard “soft rain." (Remember that Dr. Zubeck's subjects heard "dripping water.") A few have reported hearing "trucks rumble" by on the highway, and some have heard the “slow drone" of airplanes overhead. While these sounds do actually occur, none of them could possibly have penetrated into the S.D. cubicle. Are these expected sounds that result from the mistaken identification of actual body sounds, or are they auditory hallucinations?