Behavioral and physiological responses of stayers and quitters in underwater isolation

Although the tolerance of subjects (Ss) to sensory isolation has been studied over the past 35 years or so, most attention has been paid to such variables as personality characteristics and less attention to physiological measures related to endurance. Additionally, the more profound isolation environment of water immersion has been much less studied than the quiet room environment. The present study reports, for the first time, physiological data from Ss who underwent short- and long-term water immersion isolation, investigates the accuracy of time estimation, and includes psychological data on these two groups. In this study, Ss who terminated isolation in less than 3 h overestimated elapsed time, tend to be introverted and anxious, and reported substantial hallucinatory activity. Those Ss who terminated after more than 3 h, and closer to 6 h, underestimated elapsed time, tend to be extroverted, and maintained a better orientation to the isolation environment. Physiological indices of the short-termers showed no differences in EKG rate, a more rapid EEG pattern, and a different breathing pattern than did the long-termers. Most of these group differences are consistent with the notion that the short-term Ss were more aroused and felt more anxiety in the isolation environment than did the long term Ss.