Searching for Placebo Effects: Do Sensitive Personality and Breathing Instructions Influence the Experience of Flotation- REST (Restricted Environmental Stimulation Technique)?

The aim of the present study was to investigate whether the experiences and effects of 45 minutes relaxation in flotation tank were influenced by breathing instruction or by a sensitive personality. A sample of 48 persons, 20 men and 28 females (mean age 27.40 years) were randomized into two groups; with or without a breathing relaxation instruction. The second independent variable was sensitive personality (low, high) derived from the Highly Sensitive Person Scale. Dependent variables were Subjective Flotation Experience (Kjellgren, Sundequist, Norlander, & Archer, 2001) and detection threshold and upper threshold pain endurance. Main results indicated that experiences during flotation with regard to comfort and stress reduction were not influenced by instructions or by sensitive personality. These results are in line with earlier findings indicating that flotation-REST is not particularly affected by expectancies, earlier experiences, personality or surroundings in the laboratory.