Analgesia produced in women by genital self-stimulation

This study investigated the relative effectiveness of specific genital regional self-stimulation in elevating pain thresholds. Anecdotal reports in humans suggest that sexual activity and orgasm decrease a wide variety of human responses to pain and touch, but the phenomenon has not been evaluated objectively. Two types of self-stimulation, pressure and pleasurable, were applied by 10 women to the anterior vaginal wall, the posterior vaginal wall, and the clitoris. Significant increases in pain thresholds but not tactile thresholds occurred when pressure stimulation was applied to the anterior wall of the vagina or when "pleasurable" self-stimulation was applied to any of the three areas. Tactile thresholds were not significantly affected by any genital stimulation condition. However, there was a significant increase in tactile threshold but not pain thresholds in the distraction control condition. On the basis of these findings, we conclude that (a) a sensation of pleasure evoked by genital stimulation can elevate pain thresholds, (b) these pleasurable stimuli were not general "distractants" because they elevated pain thresholds but not tactile thresholds differentially, and (c) genital pleasurable stimuli activate an analgesic process that is distinct from a distraction process.     

Analgesia produced in women by genital self‐stimulation

This study investigated the relative effectiveness of specific genital regional self‐stimulation in elevating pain thresholds. Anecdotal reports in humans suggest that sexual activity and orgasm decrease a wide variety of human responses to pain and touch, but the phenomenon has not been evaluated objectively. Two types of self‐stimulation, pressure and pleasurable, were applied by 10 women to the anterior vaginal wall, the posterior vaginal wall, and the clitoris. Significant increases in pain thresholds but not tactile thresholds occurred when pressure stimulation was applied to the anterior wall of the vagina or when “pleasurable” self‐stimulation was applied to any of the three areas. Tactile thresholds were not significantly affected by any genital stimulation condition. However, there was a significant increase in tactile threshold but not pain thresholds in the distraction control condition. On the basis of these findings, we conclude that (a) a sensation of pleasure evoked by genital stimulation can elevate pain thresholds, (b) these pleasurable stimuli were not general “distractants” because they elevated pain thresholds but not tactile thresholds differentially, and (c) genital pleasurable stimuli activate an analgesic process that is distinct from a distraction process.     

Negative Dependence in Sampling

Abstract. The strong Rayleigh property is a new and robust negative dependence property that implies negative association; in fact it implies conditional negative association closed under external fields (CNA+). Suppose that and are two families of 0‐1 random variables that satisfy the strong Rayleigh property and let . We show that {Z_i} conditioned on is also strongly Rayleigh; this turns out to be an easy consequence of the results on preservation of stability of polynomials of Borcea & Brändén (Invent. Math., 177, 2009, 521–569). This entails that a number of important π ps sampling algorithms, including Sampford sampling and Pareto sampling, are CNA+. As a consequence, statistics based on such samples automatically satisfy a version of the Central Limit Theorem for triangular arrays.