The author subjected himself to seven weeks of 'environmental stimulus reduction'—isolation, asceticism, and relative sensory deprivation. After passing through a hallucinatory phase, he proceeded to what he calls 'a new condition during which repressed memories were recalled and relived … eight hundred pages of crucial repressed memories and other events, the existence of which I had never up to that time suspected'. After the experiment there was a residual effect of reorientation as far as sense of identity, sense of reality, motivation were concerned. There is a religious conversion aspect about the whole experience which arouses suspicion, but the relationship between sensory deprivation and the return of repressed memories is of interest, particularly as it might relate to sleep and dreams.