The early investigators in the field of perceptual isolation were at McGill University, especially Bexton et al. (1954). Since then there have been many subsequent works and papers on the subject. In general, published results of this type of experiment can be divided into two groups. Sometimes marked sequelae to sensory deprivation have been described (Bexton et al., 1954 and Goldberger et al., 1958). Such disturbances included thinking, imagery and time appreciation, together with delusional and hallucinatory phenomena. On the other hand, at Princeton University, Vernon et al. (1956), under very carefully controlled experimental conditions, found virtually no sequelae. A paper published from this hospital (Smith and Lewty, 1959) described a silent room which was designed, constructed and standardized to a mean sound pressure level difference of 80 decibels. (Measurements made at octave intervals from 80-10,000 c./sec.) In this particular room 20 volunteers spent varying periods from 5 hours 50 minutes to 92 hours 20 minutes under conditions of partial and complete sensory deprivation. We used a room so as to mitigate the physical effects of reduced somatic activity and fur gloves were used instead of the more common cardboard cylinders, which after a period of time produce a great deal of skin irritation and indeed abrasions, and introduce a great deal of unnecessary complications into a study of pure sensory deprivation.