The Science of Orgasm -- Book Review Essay

The Science of Orgasm

By Barry. R. Komisaruk, Carlos Beyer-Flores, & Beverly Whipple.  Baltimore:  Johns Hopkins University Press.  2006.  359 pp.

Orgasm is understudied and not well understood.  This book is a nice digest of the scientific literature on orgasm offering a broad overview of its physiology and biochemistry in rather considerable detail.   I would hesitate to recommend this for the general reader.  Much of it is highly technical.  There are few drawings or illustrations to ease the pain and the ones there are, aren't very good.  If you are a medical professional or have a strong background in biochemistry or pharmacology you will likely be able to appreciate this book more.  If you have some knowledge of anatomy and physiology and are able to persevere in the face of the dry, academic style in which this is written, it contains a wealth of information about sex, reproduction, and the biochemistry of desire that I think not too many people are aware of, even among professional physicians and pharmacists.  This book explains a lot and at the same time makes clear how much is not known and not well understood about something as basic and ordinary as sexual response.  When you see how complex the whole matter is, and how many things can affect it, and how many things can go wrong with it, it is a wonder that it works as well as it does. 

One of the more salient indicators of scientific inattention to this subject is the lack of consensus on how orgasm should be conceptualized or defined.  In a 2001 paper that provides an overview of the literature attempting to define orgasm, Mah and Binik (2001) point out two dichotomizations that occur in this literature: on the one hand between biochemical and psychological conceptualizations, and on the other between male and female orgasm, which are assumed to be different.   Mah and Binik present a table listing 25 different definitions of orgasm from a wide spectrum of viewpoints (pp 824-25).  This reflects the lack of scientific consensus on the most basic conceptualization of orgasm and its fundamental nature.  Most research on orgasm has focused on genitopelvic phenomena: muscle contractions, elevated blood pressure, tachycardia, dilation of pupils, expulsion of semen, etc., rather than on the subjective experience of orgasm.   

One conceptual distinction Mah and Binik suggest for males is between "orgasm" and "ejaculation."  They are commonly equated, but there are reasons for understanding ejaculation as simply one aspect of male orgasm and not to be equated with the entire experience.  Komisaruk et al. echo this distinction pointing out that some men with spinal cord injuries are able to ejaculate without feeling the orgasm (pp. 12, also 28-29). 

Mah and Binik continue that the psychology of orgasm, that is, orgasm as a subjective experience, has been vastly understudied in relation to the amount of study devoted to the physiology of orgasm.  Female orgasm seems to be more complicated and more controversial than male, although Mah and Binik seem to suggest that this is due to an oversimplification of the understanding of male orgasm that tends to reduce it to ejaculation.  There has been very little study of how the psychological and physiological aspects of orgasm interact and influence one another.  Despite great strides that have been made in the last fifty years, orgasm remains a black box of subjective human experience.  They point out the inadequacy of language for describing the internal experience of orgasm and how this places limitations on the scientific value of self-reports of the experience.  They discuss various typologies that have been proposed for female orgasm.  The discussion is informative and worthwhile, but the lack of detailed study and the unreliability of the data on this topic seems to be the most noteworthy conclusion from this discussion. 
"in comparison to biologically based typologies, very little research attention has been devoted to possible psychological typologies of orgasm" (p. 840)

 "The study of the orgasm experience appears to have been influenced by assumptions surrounding the identification of female sexuality with psychological experience versus male sexuality with physical performance. Almost all of the literature cited has focused on female orgasm, with very few comparisons to male orgasm.  However, male orgasm, outside of the ejaculatory processes, appears to encompass a phenomenology similar to that of female orgasm. Certainly further comparative studies are warranted." (p. 835)

 "having pre-marital sexual and orgasm experiences is linked with higher orgasm frequency [in females].  Together, these findings are consistent with ‘‘priming’’ theories of female orgasm capacity involving early sexual learning and conditioning.  Mead theorized that sociocultural differences in female orgasm capacity reflect a potential for orgasm dependent on sociocultural learning: In sexually liberal cultures, highly varied, diffuse foreplay develops this potential by promoting bodily receptivity to sexual stimulation. However, to our knowledge, no empirical evaluation of this theory has been conducted." (pp. 833-34)

 "Overall, associations between female orgasm response and psychopathological adjustment have not been supported"  (p. 834)

 "As far as we know, there have been no studies specifically measuring in detail either the physiological events of orgasm or the qualitative experience of orgasm in aging individuals." (p. 836)

"In men, testosterone production, sexual desire, penile sensitivity, and erectile capacity tend to decline with age. Latency to erection and to ejaculation increases, ejaculation is typically less forceful, and length of the refractory period becomes extended. However, there is wide variation." (p. 836)

 "In women changes relating to menopause and hormonal changes in the woman's body can affect sexual response and orgasm." (p. 836)

"Frequency of orgasm in older individuals appears to be related to marital satisfaction and previous sexual functioning and adjustment.  Overall, the physiological changes seen with aging do not necessarily result in dramatic declines in desire and capacity for orgasm. Psychosocial factors may mediate variability in orgasm functioning in aging individuals." (p. 836)

Davidson (1980) in a nice survey article on the psychobiology of orgasm offers a typology of female orgasms in which he discusses Freud, who distinguished between vaginal and clitoral orgasms, Masters and Johnson, who rejected Freud's distinction and posited a monistic view of orgasm, and Singer, who proposed a tripartite distinction between uterine, vulval, and a blended type between the other two, among many other views on the subject.  Although Davidson is heavily influenced by the physiological approach to understanding orgasm, to his credit he does see orgasm as an altered state of consciousness and grapples with conceptualizing the relationship between this special type of conscious experience and the underlying physiology. 

Since there is no scientific consensus on the conceptualization of orgasm and such a divergence of views on this topic, I am going to offer my own conceptualization of orgasm here, which is in agreement with Davidson (1980) that orgasm should be seen as a special state of consciousness.  We cannot undertake a full discussion of the nature of consciousness, but some exposition is necessary in order to develop this conceptualization of orgasm.  Consciousness encompasses awareness and there are systems of nerves within the brain that govern our awareness at any given moment called the reticularis complex.  (See my paper, Ferguson (1990) pp. 433-437).  Charles T. Tart (1980) wrote an excellent exposition of how consciousness, which we all accept as a given and as "normal," is actually a complex construct that is highly dependent on culture, language, and conditioning, and thus is highly variable within human experience.  

"Enculturation . . . builds up large numbers of emotional and cognitive constraints to ensure a reasonable degree of conformity with the values of the consensus reality within the culture.  Thus, it never occurs to us to think or have experiences about certain kinds of things, or such thoughts are actively blocked because of conditioned emotional associations." (Tart, p. 248)

Tart lists eleven major subsystems of consciousness, the sources that make up our conscious experience.  I would call these subsystems of awareness, because I distinguish between awareness -- what occupies consciousness at any given moment -- and consciousness, which is the continuity of awareness through time.  I will explain this more below.  Basically, awareness is momentary and consciousness is continuous.  The concept of consciousness is related to the concept of the self. 

The sources of awareness that Tart lists are :  Exteroception (perception of the physical environment), Interoception (perception of internal states of our body), input processing ( a very important subsystem that processes sensory information and delivers it to awareness in recognizable -- and acceptable -- forms), memory, sense of identity, evaluation, subconscious, emotions, space-time sense, motor output (the voluntary control of our body), and latent functions. (pp. 258-260)  He then offers a very perceptive analysis of workings of the myriad hypnotic processes that alter consciousness, although he does not call them that. 

Hypnotic processes are modes of altering consciousness:  that is, techniques that effect a shift in what occupies our awareness, how our attention is focused, as well as what is excluded from consciousness through a given time interval.  Awareness is related to perception.  When we perceive something, we become aware of it.  It occupies our consciousness through some interval of time.   Awareness is constantly shifting, but consciousness is the persistence of interconnected awareness through time.  Consciousness is the quality of being aware and awareness is the content of consciousness.  Reading a book, for example, is a hypnotic process.  One's awareness shifts from moment to moment, from one word to the next, from one sentence to the next, from one idea to the next, but one's consciousness is occupied by the continuous experience of this flow of stimulation that tends to exclude other inputs to our awareness.  Without a sense of time, that is, a perception of the interconnection between moments of awareness, there could be no consciousness.  This becomes an issue in people with certain kinds of brain disorders, such as Alzheimer's disease, where the connection between moments of awareness seems to disintegrate, and the person's self appears to gradually dissolve.  In "multiple personality" people report "losing time" between different modes, not only of awareness, but of engagement with the world.  The self is fragmented by the lack of a unifying consciousness. 

Sexual desire, lust, sexual arousal, and orgasm are hypnotic processes.  They shift our awareness to special states that mobilize emotional and physical response systems that are normally dormant during everyday experience.  Sexual desire, or lust, is the perception of the sexuality of another person.  It is looking at another person and feeling the possibility of sexual activity, creating a visualization of the other in a sexual context.  It is a conscious awareness of desirable sexual interaction, which is a continuing state.  It is different, from simply perceiving a person's existence, or the clothes they are wearing, or their ability to perform some task, or their physical characteristics.  What makes it different is that it mobilizes our personal emotional response system and prepares us for sexual arousal in a way that other kinds of perception do not, and therefore it is an altered mode of awareness.  Sexual arousal is the next level of intensification.  The body becomes mobilized in anticipation of sexual activity.  Internal physical sensations become more prominent in our awareness and other considerations that might inhibit sexual arousal tend to be excluded from consciousness.  Arousal is intensified through physical stimulation of the genitals and other regions of the body as well as psychic stimuli such as sound, scenario, internal visualization (fantasy), and perhaps smell.  At a certain threshold orgasm is triggered.  Involuntary physical processes are set in motion accompanied by intense awareness of pleasurable sensation that excludes nearly everything else.  Orgasm is a state where physical pleasure overwhelms awareness and obliterates the ability to attend to other inputs to consciousness.  Davidson notes this as well and relates it to the "loss of self" reported in some mystical experiences (1980, p. 311)  I differ with Davidson a little bit on this.  In orgasm the self does not disintegrate.  The self remains intact.  But normal consciousness, which is ordinarily processes input from numerous internal and external sources simultaneously, becomes overwhelmed during orgasm by internal physical sensations which become extraordinarily dominant.  Other modes of perception and awareness are not extinguished.  One can still see and hear during orgasm, but, using Tart's schemata, we might say that orgasm is a state where interoception (awareness of the internal state of one's body) is magnified to a unique predominance.  This makes it special.  One must be able to relax one's external and internal perceptual apparatus in order to orgasm.  Ordinarily we are bombarded by sensate experience from the external world as well as from our own internal thought processes.  In order to orgasm one must be able to allow those perceptions to recede from consciousness so that the physical pleasure of the orgasm occupies one's awareness to the near exclusion of everything else.  This is a hypnotic process.  It is not entirely voluntary, but it is conditioned by experience.  It is the capability of awareness to shift in a specific way under the conditions of intense sexual stimulation.  One does not orgasm from driving a car or vacuuming the carpet.  Orgasm is a special type of conscious experience that can only occur under very specialized conditions.  In my view, this is the way orgasm should be understood.  Komisaruk, et al. argue that orgasm is not a reflex, but rather a perception,  (p. 237f.)  and I concur with this  valuable insight.  That is, orgasm is not generated by muscular contractions caused by genital stimulation, which, in turn, lead to a reflexive action in the spinal column.  Genital stimulation mobilizes neurons throughout the body sending greater and greater levels of excitation to the brain.  The muscular contractions are indeed reflexive and can be elicited in the spinal column even when the spinal cord is severed.  But orgasm is not produced unless those muscular contractions are perceived by the brain as sensations.  This supports my view that orgasm should be understood as essentially a psychological phenomenon, not simply as a physical process.  The physical concomitants of orgasm are, of course, noteworthy and important, but Komisaruk and his collaborators have shown that the physical processes themselves do not constitute orgasm.  They can occur without the experience of orgasm, and orgasm can occur independently of physical arousal.  Therefore orgasm must be understood as essentially a subjective experience, a particular state of altered awareness, that is usually (although not necessarily) accompanied by specific physiological processes under the conditions of intense sexual arousal. 

Komisaruk and his collaborators have drawn upon a wealth of research that was not available to their predecessors.   The voluminous bibliography they provide cataloging this literature is a valuable feature of the book.  They point out that much of what is known about how the brain produces orgasms is based on studies of epileptic seizures.  (p. 214)  The reports that epileptic seizures can generate orgasmlike feelings suggest a basic commonality between the two phenomena. (p. 216)

A large portion of the knowledge of sexual response and orgasm has been further derived from the study of people with nerve damage, spinal chord, and/or brain injuries. 

"The sensation which accompanies orgasm is not a modality of pain or temperature sense, and certainly not a modality of touch sense.  It is probably a specialized sensation, mediated by fibers localized deep toward the center of the cord in the anterolateral column . . . The sensation of orgasm . . . appears to be a special sense, not mediated by the spinothalamic tract."  (p. 229)

"In males, the pudendal nerves convey sensory activity from the penile skin and scrotum, and the hypogastric nerves convey sensory activity from the testes.  Injury to the pudendal and cavernous nerves leading to symptoms of penile numbness or hypesthesia (lowered sensitivity) and erectile dysfunction was reported in 13 to 22 percent of men participating in a 540 kilometer bicycle race, some symptoms persisting for up to eight months."  (p. 227)

"The clitoris has been characterized as the 'most densely innervated part of the human body.'" (p. 231)

Komisaruk et al. spend a lot of time on sexual problems, which are very common and become ever more so with increasing age.  One aspect that merits particular credit is their recognition that sexual difficulties are not simply physical or biochemical, but situational, and interpersonal, as well as intrapsychic.  Sexual difficulties tend to be highly specific to the individual, although there are things that can be said about them broadly, they always have to be hedged and qualified when applied to a particular person. 

Several noteworthy facts are worth lifting out:

One of the most reliable predictors of continuing sex in old age is active sex in middle age. 

Sex in old age depends very much on the presence of an "interesting and interested partner." 

Prostate cancer is related to the absence of sex and ejaculation. 

In 1998 the FDA approved sildenafil (Viagra) to treat male erectile dysfunction.  Since then, research into male sexual dysfunction has increased.  However, research into female sexual problems has not kept pace even though a significantly higher percentage (43-31) of women than men are affected by sexual problems.

A UK study found that the risk of mortality was 50% lower in men who had frequent orgasms, defined as two or more per week, versus less than once a month. 

In women there is a significant correlation between sexual dissatisfaction, "frigidity," and heart attack. 

Orgasm seems to reduce the risk of cancer.

Orgasm helps people to go to sleep.  

Endometriosis is a condition in women where the cells which line the uterus and are shed every month during menstruation embed and grow in other areas of the woman's body (ovaries, bowel, rectum, bladder, etc.)   This causes bleeding and pain.   Orgasms seem to have a protective effect against endometriosis. 

Sexual activity late in pregnancy seems to ward off premature birth.

Orgasm seems to provide relief from migraine headaches as well as menstrual cramps. 

Sexual activity and orgasm have been shown to reduce stress.

In men, a higher frequency of ejaculations over years (four or more per week during the twenties, thirties and forties) correlates with a lower incidence of prostate cancer.

There has been some study of death during sex in men, but little on women.  "According to one medical examiner, 'death in the saddle' follows a pattern in which 'the deceased is usually married; he is with a nonspouse in unfamiliar surroundings after a big meal with alcohol.'" (p. 51)

However, death during sex is a rare occurrence, "and reports of coital death of a middle aged, middle class, male patient with heart disease who engages in sexual activity with his wife of 20 or more years in their own bedroom is even rarer."  (p. 52)

The chapter on the biochemistry of neurons was very dense for me.  I would not be able to follow this in all of its detail without a lot of illustrations and probably a great deal more exposition.  Similarly, the chapters on hormones and their effect on sexual behavior and orgasm were interesting but highly technical.  Drawings would help, but there aren't any, which indicates that this book is aimed at specialists rather than general readers. 

A considerable portion of the book is devoted to the neurochemistry of various pharmaceuticals and their effect on sexual response and orgasm.  Fortunately it is parsed in short chapters which are easy to digest.  However the content is highly technical and having an advanced knowledge of neuroanatomy and biochemistry would be helpful.  Very useful, detailed information is offered on many widely used pharmaceuticals as well as recreational drugs including anti-psychotic drugs, drugs that treat Parkinson's disease, epilepsy, antidepressants, amphetamines, barbituates, tranquilizers, marijuana, ecstasy, heroin, poppers (amyl Nitrite), and cocaine, among others.

One remark they made about alcohol I think is worth underscoring.  " Although alcohol was probably the first psychotropic used by humans and is the most widely used and abused recreational drug, its pharmacology is still poorly understood." (p. 151)  Given how ancient and how pervasive this drug is and how much contention there has been over its use in American society, I found this a remarkable statement.

They also make a similar statement about nicotine:  "the effects of cigarette smoking or nicotine itself on sexual response and orgasm have not been systematically researched, probably because nicotine does not seem to have a prominent effect.   This lack of effect is surprising considering nicotine's potent ability to mimic the action of the neurotransmitter acetylcholine."  (p. 148)  How can they conclude that nicotine does not have an effect on sexual response when it has not been studied systematically? 

There is controversy over the extent to which hysterectomy affects sexual response in women.  It seems to be due to the wide variety of relevant circumstances involved in a hysterectomy, such as whether the cervix and/or the ovaries are also removed, the woman's mental state before and after the surgery, the woman's general health, the type of surgery, whether she is pre- or post-menopausal, etc.  (p. 233-35)

They provide an interesting summary of experimental surgery done in the 1930s and 40s by James W. Watts and Walter Freeman to "improve" the lives of schizophrenics.  Frontal lobotomy is a surgery which severs the prefrontal cortex of the brain to the thalamus.  Some 20,000 of these operations were done in the United States by the 1950s.  The effectiveness of this surgery is very controversial and it has been replaced in modern medicine by psychotropic drugs, which are also very controversial.  However, I do not wish to explore this issue here.  The interest it has for me is the impact of this surgery on the sex lives of the patients.  Although results vary, there is a marked tendency toward hypersexual behavior as well as inappropriate conduct such as masturbating in public and fondling strange women and crawling into bed with other hospital patients with sexual intent after frontal lobotomy.  These findings are further amplified by studies where various sections of the brains of cats, rats, and other animals were removed, as well as studies of humans who underwent brain surgery for the removal of cancerous tumors and other reasons.  They summarize,

"Based on all of these cases, we can conclude that the 'higher functions' of the brain, such as the learning of socially acceptable behavior, are a complex process involving finely tuned inhibitions.  When the frontal regions are disconnected from the rest of the brain, that complexity is lost and, with it, the fine tuning of social graces.  Prominently disinhibited is sexual behavior, along with other complex sociocultural behavior patterns.  (p. 249)

A later chapter explains the workings of PET and fMRI technologies that are used to map the brain's functions.  These have been applied to sexual arousal and orgasm.  The limitation of these technologies, however, is that they work by measuring blood flow that supplies the neurons and brain regions, rather than the activity of the neurons themselves.  So it is an indirect measure that does not show exactly what the neurons are doing.  For example, the same regions of the brain are activated during both pleasure and pain, but it cannot be concluded that the same neurons are performing different functions or that these two subjective phenomena are somehow physiologically related.  (See pp. 265f.)  But it has been used very effectively to determine which areas of the brain are active during sexual arousal and orgasm.  For example, some women are able to reach orgasm just from thought alone, without bodily stimulation.  Orgasms of this type measured no activation of the amygdala, which does fire up during bodily induced orgasms.  So it is inferred that the amygdala registers genital sensations and other regions of the brain govern the cognitive aspects of orgasm. (p. 261)

Altogether this is a valuable source on a subject that does not receive much scientific or medical attention despite the fact that it is such a commonplace, everyday occurrence in nearly everyone's life, and has great importance to general health and well being.  It is comprehensive, detailed, and very technical discussion that draws upon a vast array of sources, few of them dealing specifically with orgasm, which means the authors had to toil through a diverse technical literature to create this focused digest -- a formidable effort worthy of the highest accolades.  Large parts of it can be daunting to read without a medical background, but perseverance will be well rewarded especially in regard to the effects of pharmaceuticals, aging, and spinal or brain injuries on sexuality.



Davidson, Julian M.  (1980)  The Psychobiology of Sexual Experience.  In The Psychobiology of Consciousness.  Edited by Richard J. Davidson and Julian M. Davidson.  New York and London:  Plenum Press.  pp. 271-332.

Ferguson, Michael  (1990)  Mirroring Processes, Hypnotic Processes, and Multiple Personality.  Psychoanalysis and Contemporary Thought.  Vol. 13, No. 3, pp. 417-450.

Mah, Kenneth and Binik, Yitzchak M. (2001)  The Nature of Human Orgasm:  A Critical Review of Major Trends. Clinical Psychology Review, Vol. 21, No. 6,
 pp. 823–56.

 Tart, Charles T. (1980)  Systems Approach to Altered States of Consciousness.  In The Psychobiology of Consciousness.  Edited by Richard J. Davidson and Julian M. Davidson.  New York and London:  Plenum Press.  pp. 243-269.