Most people who float in a sensory isolation tank go through four distinct phases during a 60-minute session: acclimatization, a transitional phase, an altered state of consciousness (ASC), and finally reorientation. The ASC phase is marked by positive emotions, deep relaxation, loss of orientation in space and time, and reduced bodily sensations and thoughts. These characteristics emerge gradually and intensify over time. The findings suggest that the therapeutic benefits of Floatation-REST for mental health conditions may be linked to the experience of these altered states.
Floatation-REST, which minimizes sensory input by having people float in warm, salt-saturated water in a dark, silent tank, produces stronger altered states of consciousness—specifically a dissolving sense of body boundaries and distorted time perception—than simply lying on a waterbed in a dark, quiet room. In a crossover trial with 50 healthy adults, a 60-minute float session led to greater relaxation, less anxiety, and less tiredness compared to the control condition. The loss of body boundaries during floating directly contributed to the reduction in anxiety, pointing to a previously unknown mechanism behind floatation's calming effects.