Abstract
Orgasm is a subjective experience accompanied by involuntary muscle contractions. We hypothesized that orgasm in women would be distinguishable by frequency analysis of a perineal muscle-derived signal. Rectal pressure, an index of perineal muscle activity, was measured continuously in 23 healthy women during different sexual tasks: receiving clitoral stimulation, imitation of orgasm, and attempt to reach orgasm, in which case the women were asked to report whether orgasm had been reached (“orgasm”) or not (“failed orgasm attempt”). We performed spectral analysis on the rectal pressure data and calculated the spectral power in the frequency bands delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and beta (13–25 Hz). The most significant and most important difference in spectral power between orgasm and both control motor tasks (imitation of orgasm and failed orgasm attempt) was found in the alpha band. An objective rule based on spectral power in the alpha band recognized 94% (29/31) of orgasms and correctly labeled 69% (44/64) of all orgasm attempts as either successful or failed. Because outbursts of alpha fluctuations in rectal pressure only occurred during orgasm and not during voluntary imitation of orgasm or failed attempts, we propose that they represent involuntary contractions of muscles in the rectal vicinity. This is the first objective and quantitative measure that has a strong correspondence with the subjective experience of orgasm.
Similar content being viewed by others
References
Bohlen, J. G., Held, J. P., Sanderson, M. O., & Ahlgren, A. (1982). The female orgasm: Pelvic contractions. Archives of Sexual Behavior, 11, 367–386.
Carmichael, M. S., Humbert, R., Dixen, J., Palmisano, G., Greenleaf, W., & Davidson, J. M. (1987). Plasma oxytocin increases in the human sexual response. Journal of Clinical Endocrinology and Metabolism, 64, 27–31.
Carmichael, M. S., Warburton, V. L., Dixen, J., & Davidson, J. M. (1994). Relationships among cardiovascular, muscular, and oxytocin responses during human sexual activity. Archives of Sexual Behavior, 23, 59–79.
Chayen, B., Tejani, N., Verma, U. L., & Gordon, G. (1979). Fetal heart rate changes and uterine activity during coitus. Journal of Clinical Psychiatry, 40, 348–351.
Graber, B., & Kline-Graber, G. (1979). Female orgasm: Role of pubococcygeus muscle. Journal of Clinical Psychiatry, 40, 348–351.
Laumann, E. O., Gagnon, J. H., Michael, R. T., & Michaels, S. (1994). The social organization of sexuality: Sexual practices in the United States. Chicago: University of Chicago Press.
Lloyd, E. A. (2005). The case of the female orgasm: Bias in the science of evolution. Cambridge, MA: Harvard University Press.
Mah, K., & Binik, Y. M. (2001). The nature of human orgasm: A critical review of major trends. Clinical Psychology Review, 21, 823–856.
Masters, W. H., & Johnson, V. E. (1966). Human sexual response. Boston: Little, Brown and Company.
Reubens, J. R. (1982). The physiology of normal sexual response in females. Journal of Psychoactive Drugs, 14, 45–46.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
van Netten, J.J., Georgiadis, J.R., Nieuwenburg, A. et al. 8–13 Hz Fluctuations in Rectal Pressure Are an Objective Marker of Clitorally-Induced Orgasm in Women. Arch Sex Behav 37, 279–285 (2008). https://doi.org/10.1007/s10508-006-9112-9
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10508-006-9112-9