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Sensory deprivation and losing weight



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

The stock of food available to the S.D. subject was more than abundant. In fact we deliberately overstocked the food chest because we expected overeating.

We thought that, as eating would be one way to break up the monotony, it would be either prolonged or occur often or both. Thus we expected our confinees to gain weight. The surprising thing is that all but two lost weight!

There was a great deal of individual variation, which was to be expected, but the length of confinement was not necessarily directly related to the loss of weight. For example, one man confined for two days lost seven pounds, but that does not mean that the rate of weight lost in S.D. is three and a half pounds per day. It is only in a very general way that we can say that the length of confinement is related to the amount of weight loss.

The table below provides the average total weight loss according to the length of confinement:


I               2.7

2              1.8

3              3.0

4              3.7

The loss of weight by S.D. subjects is hard to explain. They eat the food and yet apparently do not receive full benefit from it. We calculated that the provisions allowed an average of over three thousand calories per day, and, considering their lack of activity, that amount should have yielded a slight gain. The two subjects who didn't lose weight were confined for forty-eight hours. One weighed the same upon release and the other had gained one half a pound.

These exceptions are not significant and should be taken only to suggest the degree to which people can vary. It is of interest that on the average less weight was lost by those confined for forty-eight hours, perhaps because that length of confinement is a particularly difficult time. If people relieve tension by eating (and there are some who attribute the present-day overweight problem to that cause), then perhaps our forty-eight-hour subjects overate because of tension and thus lost less weight than others did.

Most subjects, upon being released from S.D., indicated that they were hungry, not of an empty stomach, but for specific foods that were their favorites, and particularly for a hot meal. Most of them remarked that never before had they realized how much the taste of food depends upon its being heated.

After we became aware that subjects lost weight, we wondered whether their strength was also failing. We tried to test this idea by measuring the strength of grips of our subjects, using a device called the "hand dynamometer" which registers in pounds the amount of squeeze one is capable of producing with one hand. As one continues its use, the strength of squeeze increases, and it became necessary to have a control group for purposes of comparison. We found that the control group improved their strength of squeeze by an average of four pounds, but that with S.D. subjects, upon release, the strength of squeeze depended upon the length of confinement: those confined for one day showed an increase in their squeeze of two pounds, those confined two days increased four pounds, and those confined three days lost three pounds.

Thus we see that the strength of the person's grip follows the pattern of his weight. With short confinements, Iasting one day, there is a weight loss and less gain in the strength of grip than should have occurred as indicated by the control group. With two days of confinement there is less weight loss and no impairment to the strength of grip. With three days of confinement the weight loss is larger and the loss in strength of grip is significant.

This comparison does not intend to suggest that the loss of weight causes the loss of strength of grip. Such small weight losses could hardly be expected to so affect the strength of an individual. It merely happens that weight and strength behave in a similar manner when subjected to S.D...................

……………..The data … clearly indicate that subjects in S.D. can expect to lose weight. The surprising thing is that they do not consume enough food to prevent weight loss. If we figure that four ounces of food is roughly equivalent to a hundred calories, our subjects averaged slightly under nine hundred calories per day. Although this figure is low enough to produce a loss of weight, it is still surprising that so much weight is lost in such a short time.

……………. Statistically there is no correlation between the amount of food consumed and the weight loss.  In the future we will have to keep a record, not only of the consumed food, but also the amount of water and the weight of the elimination products.

At the present, however, it is still surprising that our subjects do not eat more when an abundance of palatable food is available. It would appear that as there is so little activity and hence so little need for food the appetite is accordingly regulated.

The source of the experience

Scientist other

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