“…It is clear that the performance of isolated volunteers is not always impaired. In fact, there is evidence that immediate memory span (Myers et aI., 1964), vigilance (Smith et al, 1967, complex perceptual-motor skills (Smith and Myers, 1967), verbal learning (Vernon and Hoffman, 1956), and sensory acuity (Zubek, 1969b) may actually improve during isolation, and relatively complex mental functions have shown little, if any, systematic decline. In general, the striking alterations in perceptual organization (e.g., the bending of plane surfaces and loss of perceptual constancies) first reported by the McGill investigators have not been found in later studies.…”