Enhancement of randomness by flotation rest (restricted environmental stimulation technique).
Perceptual and Motor Skills June 1, 1995 S Sakata, J Shinohara, T Hori et al.
Floating in a sensory isolation tank increases randomness in orally generated number sequences, while lying on a bed in an isolation box decreases it. Seven student volunteers each completed one 40-minute session on a bed and two 40-minute sessions floating in a tank. Continuous polygraph recordings of EEG, EOG, ECG, and respiration showed that flotation induced more hypnagogic (drowsy) and light sleep states than the bed condition. The authors suggest that these states enhanced random generation.