Orgasm and EEG in 1976 - A Journal Article I Read
Welcome back to An Article I Read, where I summarize a scientific article relating to female orgasm (check all the past ones out HERE). As always, I have a bunch of to-be-summarized articles in a folder that I would so love to get through, but the main ones I'm into are too dense to get out quickly, so I picked a quick(ish) one that was published in 1976. *side note - I lied. This wasn't quick, but I did kind of enjoy working thorugh it - but definitely not quick*
Honestly, by necessity, I can't pontificate on this particular article too much simply because I don't know shit about EEGs. Not that I, like, know everything about the technology in the other articles I review. In fact, as you might assume, I usually know very little about any of them. However, in other articles, there's usually a bunch of assumptions and experimental design choices that I do understand and that I have a lot to say about regardless of the technology. This article isn't really full of that kind of thing for me. It's much more focused on the discussion of the EEG results, and frankly, I'm just gonna relay most of that info to you and you can do as you will; find the full article and read it yourself, ask someone who knows about EEGs, read it and move on with your life, look at it and know there is an article like this out there for future reference. Ya know - whatever you need from this.
Electroencephalographic laterality changes during human sexual orgasm. H D Cohen, R C Rosen, L Goldstein. Arch Sex Behav. Vol. 5 No. 3 (May 1976), pp. 189-99.
MY QUICK SUMMARY
These authors took 4 males and 3 females, and checked their brainwaves while resting, then mentally (sexually) arousing themselves, then physically stimulating themselves to orgasm, and then resting after the orgasm. They were interested in brain activity and particularly a switch in laterality (the dominant side of the brain) at orgasm - because that's something that happens on psychedelic drugs and on the switch from REM sleep, etc., so they thought it might happen for orgasm too. As a means to take away variables like which hand you use or if a fake orgasm can be discerned, one participant switched hands for a 2nd try, and one participant faked an orgasm first before she then reported an actual orgasm.
The authors believe this study shows the significance an EEG reading has to indicate orgasm since previous research had mostly focused on involuntary muscle contractions and blood vessel changes (vasomotor changes). They seem to be trying to assert that there is some type of 'central event' of orgasm that lies within the brain, and are sort of poo-pooing the idea that physical things are central enough to orgasm - including the rhythmic involuntary muscle contractions that were then and still are the only real agreed upon physical method for identifying an orgasm. They reported data for this, but it was a small messy set of data and couldn't support that belief.
The authors also monitored the blood congestion changes in the genitals as a means to control for actual orgasms. Although they said that this measurement was used to verify arousal and orgasm in the subjects, they only cited references that identified that type of blood congestion data as confirmation of arousal - not orgasm. In fact, I know of no studies that show blood congestion can discern between high arousal and orgasm - so that's fishy to me. In fact they did not even report the data they got from the blood congestion measurements at all - which is even more sketchy to me. Honestly, I feel like these authors were somehow trying to throw shade at Master's and Johnson's contribution to the understanding of orgasm - maybe in an attempt to stand out from the crowd and get published - that seems like a thing, although that's completely speculative on my part. But, they did intentionally ignore M&J's contribution to orgasm in a, what I might call, science-catty way that is super subtle, but would be pretty obvious and blatant to other researchers in the field. All that to say, their claims of verifying orgasms are not to be believed, and I think they knew that which is why they didn't report that data. I mean, would have been cool if they did - just to see what or if there were any correlations to what was happening in the EEG and what was happening in the blood congestions before, during, and after orgasm - even if it revealed the blood congestions measurements were not great at specifically detecting orgasm - still would have been good knowledge to have.
Anyway, I don't know much about EEGs and whether they are seeing what they purport to, so I'll take their word. What I do know is that it seems like there was some sort of peak at the timing some of the participants claimed an orgasm, but it wasn't significant for 2 males and 1 female...and there were only a total of 7 participants, soooo....this is, ya know, kinda interesting, but can't be seen as much more than a dipping of a toe in the EEG and orgasm situation. Nothing conclusive at all comes from this, and it also doesn't offer up any info about how the brainwaves relate to the physical blood and musculature related indicators of orgasm. Do they happen at the same time? One in front of the other? Does one happen sometimes when an orgasm is claimed, but the other not? When and why might that be the case? Those are crucial questions that would need to be answered before EEG reads could be understood as a marker of orgasm. Clearly this paper doesn't bring us anywhere near that conclusion.
Overall, it's a cool start that needs MAJOR follow-up.
THE ARTICLE SUMMARY
In these summaries, you can assume that anything I write is a genuine attempt to reflect what is said in the paper - even if it's shortened or summarized. My opinions, if I have any to add will either be inside brackets likes these [ME:], or in a section headed in a way that clearly lets you know these are my opinions. All quotes are from this article unless specifically noted.
You can check out the list of all the past 'A Journal Article I Read' Summaries HERE.
Introduction
Previous studies to measure physical changes associated with orgasm have focused largely on our non-consciously controlled bodily functions as well blood flow changes and muscular contractions as crucial elements of orgasm. "There is no doubt that some peripheral measures reliably correlate with the early stages of sexual arousal (Zuckerman 1971), but such changes may have little bearing on the role of central events during orgasm."
[ME: I'm honestly not sure what the authors mean by 'central events' here. After a few reads of this intro, I'm kinda thinking they are generally discussing orgasm as if the involuntary muscle contractions and release of blood congestion is maybe sort of a possible side effect of the "central" thing - which they are seeming to say is what happens in the brain. I also am confused because they site a Zuckerman review paper about arousal (not orgasm) to site that blood flow and muscular changes are a part of early arousal - which is undoubtedly true and uncontroversial even in 1976, but they also seem to be using it to say that it may not have much to do with the "central events during orgasm" - something that paper can't really speak on since it's about arousal not orgasm. It seems these authors are saying boldly that the previous work about the central role of involuntary muscle contractions and blood flow during orgasm that Masters and Johnson described less than a decade earlier is just not worth much - but don't say why - except for that the measuring of those things may be more qualitative than quantitative (as you'll see below), but to me that seems to be more about better measurements than throwing it out. Also, this paper at best is barely scratching the surface of maybe finding a correlation between EEG readings and orgasm - and is not showing us at all the relationship between the EEG readings and the physical blood and musculature related events that have been used to indicate orgasm in the past (and that these authors say may not have much to do with 'central events' of orgasm). Point is if something is going to tell us that brain waves are a better, more accurate marker of orgasm - this certainly ain't the paper that's gonna do it.]
"The research of Masters and Johnson (1966) represents a major advancement in the knowledge of the process of sexual arousal." [ME: see - I feel like they are throwing shade at M&J here. They only mention arousal, not orgasm, in their list of M&J's advancements. I indeed believe the general sense, especially at that time, is that M&J lent great advancements in the understanding of the physical aspects of orgasm as well, but clearly these researcher's ain't about it].
M&J had a substantial sample size, but data was more descriptive than quantitative [ME: Fair criticism - It's a weakness. M&J could have used a lot more specific quantitative data. However, researchers have since done studies that grew on M&J's work in more quantitative ways that reinforced and improved upon, but largely did not contradict what M&J had shown. (and I would LOVE to see more studies re-trying their work with better measuring tools) Just pointing out it's a good criticism but in no way a nullification of their work. Those things are often confused - especially in the trashing of Masters and Johnson I see from time to time.]
M&J described the release of blood congestion and involuntary pelvic muscle contractions but did not give quantitative evaluations of these observations. Even for direct measurements like heart rate and blood pressure, M&J didn't provide things like ranges and standard deviation of response. [ME: They're not wrong. Most of the evidence M&J used for recording of the involuntary muscular contractions at orgasm was super slow-mo, close up, color film recordings where one could count the visual contractions. Some were done with a specially created dildo camera where you could see the contractions from inside the vagina.]
Bartlett's study (1955) focused on heart and breathing rate during orgasm during intercourse[ME: and you know I'm already skeptical here because it's fucking bonkers to use a sex act that is great for male orgasm and shitty for female orgasm (but a common time women fake orgasm) to measure both male and female orgasm. It's ripe for getting bad data]. However, it's messy to measure heart and breathing during a sex act that is so active and might in and of itself cause changes that couldn't be discerned from orgasm. The authors prefer M&J's method of using masturbation for testing orgasm. It not only eliminates a lot of the moving, but also M&J found that (especially for women [ME: probably because they are less likely to fake during masturbation - amiright?]) masturbation orgasms appeared equally, if not more, intense than during intercourse.
A study 20 years prior (Mosovich and Tallaferro, 1954) attempted to record EEG on 6 humans during masturbation. The ability to analyze was not great back then, but through visual inspection of the EEG records, it showed a general slowing of electrical activity along with voltage increases during orgasm.
(Heath 1972) used deep and surface electrodes to measure a M/F couple having intercourse. "He reported finding consistent spike and slow-wave activity in the septal region during intercourse." However, the readings were super messy because of all the physical activity, the dude in it had bad epilepsy, and Heath also found the spiking activity in other non-sex related things, so it's to be taken lightly.
There is also experiential reports that orgasms put a person into a unique state of consciousness.
Method
Subjects
4 male and 3 female subjects; range in age 21 to 33; all good physical condition; all sexually active (5-10 orgasms a week; at least 2 masturbations per week)
One female left handed all others right handed; one male strongly homosexual (Kinsey scale 5)
Participants were paid and the experiment and the reasoning behind it were described to them
Choice of EEG Measure: The Significance of Interhemispheric Amplitude Relationships
Recent data seems to show that the different hemisphere's of the brain are "involved to different extents in cognitive abilities (Dimond 1972)" So, in right handed people the left hemisphere seems to deal with verbal activities while the right seems to deal with "visual, spatial, musical, and emotional inputs (Harnard 1973)." This shows up in EEGs as "amplitude asymmetries." Reversals of this asymmetry has been found in average people when doing things like switching from verbal to visual tasks, going from REM to non-REM sleep, and while on hallucinagenic drugs. So, orgasm may also be associated with an extreme change in cerebral activity like those other activities, and the researchers thought it would be worth checking for a quantifiable reversal of this amplitude asymmetry during the orgasm.
[ME: So, best I can understand, I believe this means that the EEG from one side of the brain is stronger than the other and then when the activity change occurs (REM to non-REM sleep, not orgasm to orgasm, etc.) the opposite side becomes stronger during that time. I truly don't know enough about EEGs or brain activity, and couldn't find much easily accessible info on the web, to know if this situation is more complicated.]
Recording Methods
There's a description of the EEG and recording equiptment. There were separate measurements taken from the left and right side.
The values attained from right and left side were each plotted against time
Ratios of the Right/Left readings were calculated for each epoch [ME: in EEGs, and epoch is a time interval at which the readings are taken from the continuous signal. Table 1 in this paper later says the epoch intervals were 1 sec]
Then for each phase of the experiment (there are 4 - see below) an average of those epoch ratios was created.
"Statistical significance of the changes was ascertained on the basis of the two-tailed t test" [ME: I'll be honest, I'm a bit confused about what exactly they are checking. Which are the 'changes' they are referring to? My best guess is that they are talking about the change from one phase of the experiment to the other of the average Right/Left reading that was calculated, but I'm not completely sure. I looked up some different sites about two tail t tests (because I ain't no expert in statistics - that's for sure) and I'm still not completely sure, so take that for what you will]
Males placed a gauge at the base of the penis to measure penile tumescence (blood congestion - or basically level of erection).Females placed a "relative blood flow transducer mounted on a diaphragm ring" inside their vagina for the same purpose. This was used to continuously monitor during the experiment the blood flow changes that are known to accompany sexual arousal.
"For both sexes, these data provided verification of the subjective report of arousal and orgasm. The effects of manual stimulation, for example, were clearly apparent on the polygraph tracing which recorded penile tumescence." [ME: Alright, this statement is heavily overreaching. Clearly the blood congestion info would give indicators about physical arousal - not controversial in the slightest. Any person of medicine would know that straight up - of course the results of penile masturbation would show up - unless he's jerking on a limp dick that really isn't into it and stays completely and utterly limp. BUT, they also go further and say it provided verification for orgasm as well. How? What results of blood congestion monitoring will uniquely indicate an orgasm and not just high levels of arousal? Or a loss of arousal (without orgasm) after arousal? Where is the studies that indicate what this blood congestions related marker of orgasm might be? These authors certainly don't cite anything like that. They are only citing arousal - not orgasm- related studies. They have to know better, so it's a little suspect that they are just trying to slide that little orgasm line in. That's sketchy, bro. It makes me think they are really stretching to make the orgasm connections in this study that they were hoping to.]
Experimental Procedure
For anonymity each subject was assigned a code and that code and the subsequent data were analyzed blindly.
Subjects were taken into a lab where the recording equiptment was connected. They were told to lie on their backs with head resting comfortable on a pillow.
The were told their eyes should be either constantly open or constantly closed throughout the experiment. Only one subject said they could not maintain that.
The experimenter left after the subjects were settled and did not return until after the experiment, so the subjects could have privacy.
The EEG and genital blood congestion changes were monitored during 4 stages
1 - "An initial adaption period, during which the subject had been instructed to refrain from movement and to breath regularly"
2 - A period of approximately 15 minutes signaled to begin when a selection of rhythmic music began. The subjects were to fantasize sexual imagery without any physical simulation. "Two subjects were shown erotic films and pictures in order to enhance sexual fantasy"
3 - "Each subject manually masturbated until one or more orgasms were attained. In order to signal orgasm, the subject was instructed to depress a switch at the onset of the climax and to release the switch as soon as the orgasm was completed."
4 - 15 minutes of rest post- climax
Each phase was approximately 15 minutes, so the total sessions were about 1 hour. After the recording equiptment was removed each subject was "required to fill out a questionnaire, reviewing their subjective response to the experience."
Stimulation Methods
"All subjects used manual stimulation to attain orgasm. A specially DC-operated electric vibrator (Panabrator) was also used by three female subjects and one male subject." [ME: so ALL the female subjects and 1/4 of the male subjects].
Masters and Johnson demonstrated masturbation is the most reliable and consistent methods for orgasm in lab and also the large motor functions during sex make EEG reading difficult. "Self-stimulation, particularly when vibrator assisted, can be managed with minimum overt bodily movement, making possible analysis of relatively artifact free EEG records."
RESULTS AND DISCUSSION
[ME: I'm going to report this in a bit of a different structure than how it's written simply because it feels more understandable to me. I'll report all the specifics about each subject under their code number. You can see them in the table below - some will have more than 1 instance of experimentation. Then I'll add other comments, etc. from the results conclusion in bullet points]
0813
0817
0816
0814
0812
0811
0504
Table 1:
Each experimental instance (7 total subjects, 12 total instances) is listed.
The average ratio of Right/Left readings for the successive 1-second epochs for 3 periods - preclimax, climax and post climax - are listed alongside the Standard Deviation (SD) for that average.
N - indicates the number of epochs (or 1 sec intervals of Right/Left ratios that were used during that time period to create the average for each of the 3 phases). Not all epochs in each phase were used, however.
"Only those portions of record during which the EEG appeared from visual inspection of the tracings to be most stable and artifact free" were used
"The postclimax measurements were taken soon after orgasm. However, in several records, especially for male subjects, orgasm was followed by a short period of unrest, manifested on the recording as muscle movement." So only after EEG became stable were the postclimax readings used.
"Determination of the beginning and end of the period of orgasm was based on the subject's signal (press on a switch) and genital measurements." [ME: it mentions genital measurements here, but it never releases the data from those, and doesn't even tell how the genital measurements were used to determine the climax period....or why it was used. What difference did the genital measurements make on which epoch were used? It's weird to me that they just drop that in and don't follow up on it at all.]
Those experimental instances marked with a superscript 'a' after the SD in the Climax portion are those in which the researchers found significant difference between the Right/Left ratios versus the ratios pre-climax. In other words, these are ones in which there seemed to be an indicator of orgasm related to the change in right versus left EEG readings. Specifically except for (0811), who was left handed, the change consisted of a large amplitude increase in the right and much smaller in the left. This occurred regardless of the pre climax ratio (those both above and below 1).
Some comments from the post experiments questionnaire are included in the last column
More Results:
All subjects reported successfully achieving 1 or more orgasms
Except for (0811) and (0813) who reported orgasm felt somewhat "less intense" all subjects said orgasms felt typical
Because the baseline EEG ratios were so variable between subjects, it was not possible to combine data from different subjects. The analysis was done on a subject by subject basis [ME: in other words, you could not just use the total info from this group of people to predict how any one person's EEG might read at orgasm - you would need to get their individual baseline and then it might indicate what orgasm EEG could look like for them and them only...but also, this study is not even enough to predict that on an individual basis, it's just kind of a possible start to looking more into that possibility.]
There is necessarily a smaller time duration in climax compared to pre-climax. This difference in amount of epoch ratios (N) used for pre-climax and climax could seem problematic for testing significance of the ratio change between the two, but the authors feel the robustness of the resulting statistical significance calculations indicated that this is not a problem.
To ensure that the motor movement of the hand being used for masturbation wasn't the reason for seeing the Right/Left amplitude ratio switch at orgasm, one male subject (0817) did this experiment once with his right hand and then another with his left. In both cases the ratio change from preclimax to climax was deemed statistically significant and both instances showed similar [Me: their emphasis not mine]shifts at orgasm.
To test whether a faked orgasm would look similar, a female subject (0811) produced a fake orgasm prior to her real one in the same experimental session. "The 'faked' orgasm involved the same pattern of overt movement and muscular contractions, but without the subjective experience of sexual climax."[ME: umm - I think what they meant to say was that the subject reported mimicking the same muscular qualities of orgasm. We don't know if she did because that wasn't actually recorded. The particular way the pelvic muscles involuntarily contract during orgasm has been indicated in more than a couple studies as dissimilar from voluntary muscle contractions, and is seemingly the best way yet we have to mark an orgasm and discern it from high arousal or faked orgasms....So saying that the muscular contractions were the same is 1. not verified by the researchers themselves and 2. not a trivial thing to assert in a study about orgasm.]
There were not significant amplitude ratio changes during the faked orgasm. "It should also be pointed out that there was no increase in vaginal blood flow during the pseudo orgasm, contrasting with the marked increase which took place during the real orgasm." [ME: I'm interested in this because they didn't check pelvic muscular activity, which is clearly in the literature as a marker of orgasm and the only real unique marker I've seen in literature. They were checking the blood congestion. I don't know how their equiptment reads - is it about how quickly blood flow changes or is it about the level of blood congestion? Anyway, was it just indicating increased blood congestion which is related to increased arousal? or was it showing a specific and unique change that they are saying indicates orgasm? If they did, I'm pretty sure that's a novel discovery. I have never seen studies that show measurements related to blood giving a unique reading that aligns to orgasm - only readings aligning to arousal. My guess is it's not a unique reading that indicates orgasm - it's just showing arousal and like so many researchers, they seem to just willy nilly throw around words and ideas related to orgasm that are really related to arousal and don't give a shit. That's probably related to why we aren't seeing the data for the genital checks they did. They aren't good at indicating orgasm, so they aren't convenient results to share. I mean, that's my take at least.]
2 male participants didn't have discernable changes in EEG. The researchers hypothesize that this is because participant 0813 masturbated an hour before showing up for this masturbation experiment [ME: bad form, my dude.] and that participant 0816 "reported being devoid of 'mental activity' during the recording period and also judged the orgasm as low intensity. Furthermore this subject reported keeping his eyes open during the entire period of masturbation, and it may be that laterality changes are less clearly apparent under conditions if alpha-blocking"
Figure 1 :
shows "the clearest segments of preclimax, climax, and postclimax records obtained from subject 0817." There is a visual clear difference in Right vs. Left amplitude ratio - which was also calculated and confirmed quantitatively
There was also a visually noticeable frequency change - which for this study was only noted through visual inspection. These apparent frequency changes were noted in 5 of the 8 experimental instances in which right/left amplitude ratios were found to change during orgasm.
Conclusion
The researchers thought the quality of the EEG changes at orgasm might be different from the other types of "amplitude asymmetries they were seeing in the literature. "Thus it is a qualitatively different kind of interhemispheric change unrelated to other changes described so far in the scientific literature. This appears to be better interpreted as indicating a dissociation between the right and left EEG, with a change in the right of such a nature and magnitude that it clearly suggests a predominant change in the hemisphere."
Their final words: "This study has demonstrated that the computation of hemispheric amplitude relationships provide a viable methodology for quantitative assessment of orgasmic response. In fact, the amplitude ratio changes observed were even greater than those recorded under states of sensory deprivation or hallucinogenic drugs (Goldstein et all., 1973)" [ME: I don't think this provides a viable methodology for quantitative assessment of orgasmic response. I think it provides some tools for possibly looking further into the future creation of a viable brainwave-related marker for orgasmic response, ya know?]