Floatation Tank – The Science of Sensory Deprivation Therapy


Floatation tanks are increasing in popularity, offering eager psychonauts a chance to explore this unique state of mind of sensory deprivation.

The Brain Without Sensory Input

Deprived of external stimuli, the brain generates its own. Parts of the visual field light up in unrecognizable shapes, which eventually morph into more complex manifestations such as dots, lines and grated patterns.

With the advent of brain imagining techniques, scientists have been able to capture the brain basis of such finicky visual hallucinations during sensory deprivation. In 2000, one such study found that volunteers’ visual cortexes became more active after less than an hour of visual deprivation.


Hallucinations may also occur in other sensory domains:

For me, it was auditory: initially, I heard a beautiful aria drifting in and out, like music from a faraway phonograph; soon it morphed into a full symphony before settling into a simple, tribal beat. Incredibly, I did not recognize any of these tunes; my brain was spontaneously generating them. – Shelly Fan, Discover

Exercising Creativity and Concentration in the Tank


A small study of five university professors found that six 90-minute float sessions allowed them to generate more “creative” ideas, which coincided with a self-reported increase in free imagery and remote associations. Similarly, in a study with 40 university students, a single hour of flotation increased their scores on a standardized test used to measure creativity.

A far more researched effect of flotation is that it enhances performance in a variety of athletic and musical tasks that require high levels of concentration and visual-motor coordination, including basketballtennisarchery and jazz improvisation. In a sample of 13 jazz students, four sessions enhanced their technical performance one week after the last flotation experience, suggesting the possibility of lasting benefits.

Dr. Peter Suedfeld, a pioneering psychologist in the field, speculates that flotation may enhance creativity and performance in a manner similar to that of sleep or meditation. Research has shown that during resting states the brain repeatedly rehearses newly learned skills and consolidates recently acquired knowledge for long-term storage.

However, Suedfeld says, compared to sleep or meditation, such “twilight” states are more easily achievable without prior training or conscious effort via flotation. 

Physical Relief and Benefits of Floating


Cognitive perturbations only make up half of the flotation experience; far more noticeable are the physical effects. 

In the early 1980s, a group of psychologists at the Medical College of Ohio initiated a series of experiments that looked at the physiological responses to floating. Both within and across flotation sessions, blood pressure and levels of stress-related hormones dropped – effects that persisted long after the cessation of the last flotation experience.

In 2005, a meta-analysis further confirmed that flotation was more effective at reducing stress than other popular methods such as relaxation exercises, biofeedback or relaxing on the couch.

Floating Away: The Science of Sensory Deprivation Therapy | Discover Magazine