"Both bottoms and tops reported increases in relationship closeness and decreases in psychological stress from before to after their scenes (Ambler et al., under review; Sagarin, Cutler, Cutler, Lawler-Sagarin, & Matuszewich, 2009), but bottoms also showed increases in physiological stress as measured by the hormone cortisol (Sagarin et al., 2009). We found this disconnect between psychological stress and physiological stress to be very interesting, and we wondered whether it might indicate that bottoms have entered an altered state of consciousness. To test this theory, we ran a study in which we randomly assigned switches (BDSM practitioners who sometimes take on the top role and sometimes take on the bottom role) to be the top or the bottom in a scene (Ambler et al., under review). The results revealed that both bottoms and tops entered altered states of consciousness, but they entered different altered states. Bottoms entered an altered state called “transient hypofrontality” (Dietrich, 2003), which is associated with reductions in pain, feelings of floating, feelings of peacefulness, feelings of living in the here and now and time distortions. Tops, in contrast, entered the altered state known as “flow” (Csikszentmihalyi, 1991), which is associated with focused attention, a loss of self-consciousness and optimal performance of a task. We believe that these pleasurable altered states of consciousness might be one of the motivations that people have for engaging in BDSM activities."