Friday, July 19, 2013

UCLA's SPAN Lab Touts Empty Porn Study As Ground-Breaking

Nothing Correlates With Nothing In SPAN Lab's Latest Porn Study


[This was first published as a reply blog post to a "Psychology Today" blog post that featured an interview with Dr. Nicole Prause, co-author of the study discussed here.]

The authors of this study believe their findings indicate that "hypersexuality" (in this case, inability to control porn use) can be explained by high sexual desire rather than porn addiction. In our view, their data do not remotely support their belief.


Participants: 52 test subjects were recruited through ads "requesting people who were experiencing problems regulating their viewing of sexual images." The participants (average age 24) were a mix of males (39) and females (13). 7 participants were not heterosexual. 

What They Did: EEG readings (electrical activity on the scalp) were taken as participants viewed 225 pictures. 38 of the pictures were sexual, and all involved one woman and one man. This particular EEG reading (P300) measures attentiveness to stimuli.

Participants also completed 4 questionnaires: Sexual Desire Inventory (SDI), Sexual Compulsivity Scale (SCS), Cognitive and Behavioral Outcomes of Sexual Behavior Questionnaire (SBOSBQ), and the Pornography ConsumptionEffect Scale (PCES).

Purpose: To seek a correlation between EEG reading averages and participants' scores on the various questionnaires—on the theory that any correlation would shed light on whether problematic porn use is a function of addiction or mere high libido.

Outcome: The authors of the study claim to have found a single statistically significant correlation among all the data gathered:
"The only correlation reaching significance was the difference score calculated between neutral and pleasant-sexual conditions in the P300 window with the desire for sex with a partner measure."
SPAN Lab presents two conflicting arguments to support its claim that "porn addiction doesn't exist":
  1. On one hand, the researchers argue that a single negative correlation between EEG readings and selected sections of the Sexual Desire Inventory means porn addiction doesn't exist.
  2. On the other hand, they argue that the lack of correlations between EEG readings and 3 other questionnaires means porn addiction doesn't exist.
We will show that:
  1. The single correlation between EEG readings and Sexual Desire Inventory scores claimed by SPAN lab does not actually exist.
  2. The the lack of correlations between EEG and questionnaires is easily explained by a) heterogeneous group of subjects (males, female, non-heterosexuals) viewing straight porn, and  b) questionnaires that do not accurately assess compulsive Internet porn use.

No genuine correlation (or relation) in the study


The study's title, along with the many headlines, state that a correlation (relation) was found between "sexual desire" as measured by the Sexual Desire Inventory and EEG readings. Not so. The correlation was attained by using only certain questions from the Sexual Desire Inventory (SDI) That is, they based their conclusion on the partial SDI data relating to desire for partnered sex.

The Sexual Desire Inventory has questions about desire for masturbation and desire for sex with a partner. "Sexual desire" is a measure of both groups of questions. Here's the key point: no statistically significant correlation was found between scores on the entire Sexual Desire Inventory and EEG readings. Thus there is no support for the study's conclusion that:
"Brain response was only predicted by a measure of sexual desire. In other words, hypersexuality does not appear to explain brain differences in sexual response any more than just having high libido." (From interview with Nicole Prause, corresponding author for the study)
Put simply, when the researchers used the:
1.     SDI questions relating to partnered sex only, they found a slight negative correlation.
2.     When they used the entire SDI, including questions about masturbation, they found no significant correlation.

Had the authors been honest the name of the study would have been: "Sexual Desire is NOT Related to Neurophysiological Responses Elicited by Sexual Images"

There are two massive problems here, which we'll expand on:

1 - Their conclusion is unfounded because, as expanded on below, the researchers constructed an empty correlation. Their supposed correlation was not with "sexual desire" as measured by the SDI (as they claim), but merely with dyadic-interest (a subscale of the test).

2 - The conclusion is based on the astonishing belief that, "If you have high libido you somehow cannot have addiction." In other words, in their view, high libido and addiction are mutually exclusive.

Questionable use of Sexual Desire Inventory (SDI) questionnaire


Keep these key points in mind when reading this complex section:
  1. Only the entire Sexual Desire Inventory  (all 14 questions) is a valid measure of "sexual desire."
  2. The developer of the SDI (Ilana Spector) agrees with #1 above.
  3. Prause stated that the "dyadic questions" have been used before as a measure of "sexual desire." This is false.
  4. Prause cited two studies to support the above claim. Both studies used the entire SDI, not just the dyadic questions.
  5. Prause made two glaring mistakes in describing the Sexual Desire Inventory (SDI)
The questionnaire from which the researchers cherry-picked their partial data was entitled "Sexual Desire Inventory." As a consequence, they took the liberty of creating both an abstract and a study write-up that use the words "sexual desire" repeatedly—63 times in fact. This is not trivial as the abstract implies that the study will find that problem porn users have either sexual "addiction" (quotes supplied by the researchers) or "a non-pathological variation of high sexual desire." (This, again, is the dubious mutually-exclusive hypothesis: either "high sex desire" or "addiction," but not both.)

The study results actually shed no light on which outcome is correct, but the constant use of the term "sexual desire" implies that they have, and that the "high sexual desire" hypothesis was supported by their data. This constant use of the term "sexual desire" leaves the casual reader with the impression that problem porn users merely have "high libido," an impression Prause painstakingly reinforced in the above interview and her press release about the study.

According to everything we can find, the SDI is a 14-question test. Nine of its items address partnered ("dyadic") sexual desire and five address solo ("solitary") sexual desire (not seven and seven, as researchers state).

According to one of its developers, Ilana Spector, the SDI is intended to be administered as a single unit:
"The scale was only validated using ALL the items both solitary and dyadic.... The scale was not designed to be used [as it was here] nor was it validated that way."
The SDI is an "all or none" measuring tool for "sexual desire," not "half."

SPAN Lab itself acknowledges that the only EEG study published on sexual desire used the entire SDI. Yet here, SPAN Lab ignored the data about solitary sex—the very activity their subjects claimed to be unable to control—and constructed a correlation using only the dyadic questions in the test.

The lab suggests that, "The dyadic subscale is commonly used as an index of trait sexual desire level."

This appears to be a lie. Where is the evidence to support this claim? Both studies SPAN Lab lists in support of this untruth used the entire 14-question SDI. (Appetitive Responses to Sexual Stimuli Are Attenuated in Individuals with Low Levels of Sexual Desire and Attention and emotional responses to sexual stimuli and their relationship to sexual desire. The latter was conducted by Prause herself.)

Also notice SPAN Lab's claim that it has measured "trait sexual desire" using (a sub-scale of) the SDI. Spector took issue with this as well,
"I don't think that the word "trait" should be used to describe sexual desire. I think of traits as much more stable characteristics, and sexual desire (both solitary and dyadic) is subject to fluctuations over time, circumstances, etc."
In short, SPAN Lab's claim that it has measured "trait sexual desire" is entirely without foundation. When one adds back the missing scores from the masturbation questions, subjects nearly all report fairly uniform (high) sexual desire, and there is quite likely no statistically significant correlation between their EEG data and anything.

Removing the solo-sex questions is the equivalent of researchers,
  • asking people who couldn't control their eating to describe their food intake over a week,
  •  then throwing out the stats relating to snacking on junk food,
  • and then publishing a conclusion that "Obesity is a function of appetite at mealtime, and unrelated to uncontrolled snacking or addiction."
Undaunted, the researchers then created a headline for their study implying they had found that uncontrolled porn use correlates with "sexual desire." The actual claim is that participants reporting greater desire for partnered sex showed less arousal to visual erotica.

A more telling way to state this pseudo-correlation (based, as it is, on partial sexual-desire data) is that, "Those who find porn the most arousing have least desire for partnered sex." 

This is potentially a sign of psychological problems. As a psychology professor explained to us,
"Desire for dyadic sex indicates a need for intimacy and emotional closeness as well as physical pleasure (a point noted by Spector, one of its developers). Emotional closeness in an intimate relationship is usually regarded as an indication of psychological health. In fact, intimacy and closeness in a relationship is usually regarded as an essential part of what it means to be a human being. So the single significant correlation in the study is pointing to a psychological problem for people who get too wrapped up in sexual images."
Indeed, we have read hundreds of self-reports of heavy Internet porn users who report inability to become aroused by real partners as their porn use escalates. Gay or straight, their interest in real partners and intimacy generally rebounds within weeks or months of quitting Internet porn.

In short, the researchers scored the SDI incorrectly and mislabeled the dyadic-interest score as general "sexual desire." They should not have done that. But, if we go along with their scoring, we find that low interest in intimacy (indicative of poor psychological health) is associated with higher EEG averages in response to sexual images. 

This is not, in fact, a strong argument that subjects' porn use is better explained by "high libido" than "addiction."

Finally, it's important to note that the study contains two errors in regard to the SDI. Quoting the study:
 "The SDI measures levels of sexual desire using two scales composed of seven items each."
 In fact, the Sexual Desire Inventory contains nine partnered questions, four solitary questions, and one question that cannot be categorized (#14).

Second mistake: Table 2 says the Solitary test score range is  "3-26," and yet the female mean exceeds it. It's 26.46--literally off the charts. What happened? The four solitary sex questions (10-13) add up to a possible score of "31".

The lively media blitz, which accompanied publication of this study, bases its attention-grabbing headlines on partial SDI results. Yet the study write-up contains glaring errors about the SDI itself, which do not engender confidence in the researchers.
   

High desire is mutually exclusive with addiction?


The second major problem with this study is the implication that high sexual desire scores would indicate participants don't have addiction. The concept that "high sexual desire" somehow rules out addiction is astounding. Its irrationality becomes clear if one considers hypotheticals based on other addictions.

For example, does such logic mean that being morbidly obese, unable to control eating, and being extremely unhappy about it, is simply a "high desire for food?" Extrapolating further, one must conclude that alcoholics simply have a high desire for alcohol, right? In short, all addicts have "high desire" for their addictive substances and activities (called "sensitization"), even when their enjoyment of such activities declines due to other addiction-related brain changes (desensitization).

Most addiction experts consider "continued use despite negative consequences" to be the prime marker of addiction. After all, someone could have porn-induced erectile dysfunction and be unable to venture beyond his computer in his mother's basement. Yet, according to these researchers, as long as he indicates "high sexual desire," he has no addiction. This paradigm ignores everything known about addiction, including symptoms and behaviors shared by all addicts, such as severe negative repercussions, inability to control use, cravings, etc.

Is this study part of a rash of studies based on the peculiar logic that any measure of "high desire," however questionable, grants immunity from addiction? A Canadian sexologist endeavored to paint this same picture in a 2010 paper entitled, Dysregulated sexuality and high sexual desire: distinct constructs? Noting that people who seek treatment for sexual behavior addictions report both dysregulated sexuality and high desire, he boldly concluded:

The results of this study suggest that dysregulated sexuality, as currently conceptualized, labelled, and measured, may simply be a marker of high sexual desire and the distress associated with managing a high degree of sexual thoughts, feelings, and needs.

Again, sexual behavior addiction itself produces cravings that often show up as "a high degree of sexual thoughts, feelings, and needs." It's simply wishful thinking to suggest "high sexual desire" disproves the existence of addiction.

In her press release, Prause makes much of the fact that, "The brain's response to sexual pictures was not predicted by any of the three questionnaire measures of hypersexuality."

However, not only is the absence of correlation not causation, there are far more likely explanations for the lack of correlations between the EEG averages and the questionnaires administered. We'll look at them next. 

Studies that directly refute "porn addiction is really high desre" model:
Quote: "Moreover, it was shown that problematic cybersex users report greater sexual arousal and craving reactions resulting from pornographic cue presentation. In both studies, the number and the quality with real-life sexual contacts were not associated to cybersex addiction."
Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014).
This fMRI study found that the more porn the subjects used, the less gray matter in the striatum. The striatum is a complex set of structures. It includes the reward center (ventral striatum) and the dorsal striatum, which also goes by several names. Less gray matter means fewer nerve connections (dendrites and axon terminals) in reward-related areas. Put simply, less gray matter in the striatum mean less reward activity, and a decline in dopamine signaling (desensitization).
Lead author Simone Kühn said -
"That could mean that regular consumption of pornography more or less wears out your reward system."
Simone Kühn continued -
"We assume that subjects with a high porn consumption need increasing stimulation to receive the same amount of reward."
Kühn says existing psychological, scientific literature suggests consumers of porn will seek material with novel and more extreme sex games.
"That would fit perfectly the hypothesis that their reward systems need growing stimulation."

Why no correlations between questionnaires and EEG readings?


Prause's second argument is that the lack of correlations between subjects EEG readings and 3 other questionnaires means porn addiction doesn't exist. Two major reasons account for the lack of correlation:
  1. The researchers chose vastly different subjects (women, men, heterosexuals, non-heterosexuals), but showed them all standard, possibly uninteresting, male+female porn. Put simply, the results of this study are dependent on the premise that males, females, and non-heterosexuals are no different in their response to sexual images. This is false - see below.
  2. The Sexual Compulsivity Scale (SCS) isn't a test of Internet-porn use or porn addiction. In the press, Prause repeatedly pointed to the lack of correlation between EEG scores and sexual compulsivity scales, but there is no reason to expect a correlation in porn addicts.
Unacceptable diversity of test subjects: The researchers chose vastly different subjects (women, men, heterosexuals, non-heterosexuals), but showed them all standard, possibly uninteresting, male+female porn. Standard procedure for addiction studies is to select homogeneous subjects in terms of age, gender and orientation (plus a homogeneous control group) in order to avoid distortions caused by such differences.

An experiment assessing cue-induced reactivity for cocaine might get by with a heterogeneous group males, females and gays, but not a study measuring arousal to porn. This alone explains the lack of correlations. Previous studies confirm large differences between males and females in response to sexual images. See, for example, Gender Differences in Sexual Arousal and Affective Responses to Erotica. and Skin sympathetic nerve activity in humans during exposure to emotionally-charged images: sex difference


Can we be confident that a non-heterosexual has the same enthusiasm for male-female porn as a heterosexual male? No, and his/her inclusion could distort EEG averages rendering meaningful correlations unlikely. See, for example, Neural circuits of disgust induced by sexual stimuli in homosexual and heterosexual men: an fMRI study.

Surprisingly, Prause herself stated in an earlier study that individuals vary tremendously in their response to sexual images:
Film stimuli are vulnerable to individual differences in attention to different components of the stimuli (Rupp & Wallen, 2007), preference for specific content (Janssen, Goodrich, Petrocelli, & Bancroft, 2009) or clinical histories making portions of the stimuli aversive (Wouda et al.,1998).
Still, individuals will vary tremendously in the visual cues that signal sexual arousal to them (Graham,Sanders, Milhausen, & McBride, 2004).
Maybe Prause should read her own statements to discover the reason why her current EEG readings varied so much. Individual differences are normal, and large variations are to be expected with a sexually diverse group of subjects.

Irrelevant questionnaires: The SCS (Sexual Compulsivity Scale) isn't a test of Internet-porn addiction. It was created in 1995 and designed with uncontrolled sexual relations in mind (in connection with investigating the AIDS epidemic). The SCS says:
"The scale has been should [shown?] to predict rates of sexual behaviors, numbers of sexual partners, practice of a variety of sexual behaviors, and histories of sexually transmitted diseases."
Moreover, the SCS's developer warns that this tool won't show psychopathology in women:
"Associations between sexual compulsivity scores and other markers of psychopathology showed different patterns for men and women; sexual compulsivity was associated with indexes of psychopathology in men but not in women."
Furthermore, the SCS includes partner-related questions that Internet-porn addicts might score quite differently compared with sex addicts, given that compulsive porn users often have a far greater appetite for cyber erotica than actual sex.

Another questionnaire the researchers administered is the PCES (Pornography Consumption Effect Scale), which has been called a "psychometric nightmare," and there's no reason to believe it (or the SBOSBQ) can indicate anything about Internet porn addiction or sex addiction.

Thus, the lack of correlation with these questionnaires contributes no support to SPAN Lab's conclusions.

No pre-screening: SPAN Lab's Prause acknowledges that,
"This study only included people who reported problems, ranging from relatively minor to overwhelming problems, controlling their viewing of visual sexual stimuli."
Standard procedure for addiction neuroscientists is to screen subjects with an addiction test in order to compare those who test positive for an addiction with those who do not. These researchers did not do this, even though an Internet porn-addiction test exists.

Instead, researchers administered the Sexual Compulsivity Scale (SCS) after participants were already chosen. They lumped people with minor problems together with those with major problems, averaged their SCS scores, and then made far reaching, entirely unsupported, claims that they had dismantled the concept of porn addiction.


Use of generic porn for diverse group subjects: SPAN Lab admits that its choice of "inadequate" porn may have altered results. Even under ideal conditions, choice of test porn is tricky, as porn users (especially addicts) often escalate through a series of tastes. Many report having little sexual response to porn genres that do not match their porn-du-jour—including genres that they found quite arousing earlier in their porn-watching careers. For example, much of today's porn is consumed via high-definition videos, and the stills used here may not elicit the same response.

Thus, the use of generic porn can affect results. If a porn enthusiast is anticipating viewing porn, dopamine (brain activation) presumably rises. Yet if the porn turns out to be some boring heterosexual pictures that don't match his/her current genre or stills instead of high-definition fetish videos, the user may have little or no response, or even aversion. "What was that?"

This is the equivalent of testing the cue reactivity of bunch of food addicts by serving everyone a single food: baked potatoes. If a participant doesn't happen to like baked potatoes, she must not have a problem with eating too much, right?

 

More concerns about the study


No control group and serious misrepresentations: The researchers did not investigate a control group of non-problem porn users. Without any evidence of what normal EEG averages would be in response to the erotica they presented, it's impossible to say that the partial-SDI data on which the researchers rely are unique to hypersexuals.

Without a control group, Prause has no idea what a "normal" EEG response to porn should be, yet she is making claims in the press, such as:
 Prause: "The reason these findings present a challenge is that it shows their brains did not respond to the images like other addicts to their drug of addiction."
Actually, P300 readings were higher for porn images than for neutral images, which is exactly what would be expected for someone with an addiction. Commenting under the Psychology Today interview of Prause, Psychologist John A. Johnson said

"My mind still boggles at the Prause claim that her subjects' brains did not respond to sexual images like drug addicts' brains respond to their drug, given that she reports higher P300 readings for the sexual images. Just like addicts who show P300 spikes when presented with their drug of choice. How could she draw a conclusion that is the opposite of the actual results? I think it could be due to her preconceptions--what she expected to find."

In short, what Prause boldly proclaimed in her many media interviews is not backed up by her results. Let's further examine this misrepresentation:
Mustanski: What was the purpose of the study?
Prause: Our study tested whether people who report such problems look like other addicts from their brain responses to sexual images. Studies of drug addictions, such as cocaine, have shown a consistent pattern of brain response to images of the drug of abuse, so we predicted that we should see the same pattern in people who report problems with sex if it was, in fact, an addiction.
Prause's reply to Mustanski indicates that her study was designed to see if the brain response to sexual images for people reporting problems with sex was similar to the brain response of drug users when they encounter images of the drug to which they are addicted.

A reading of the cocaine study she cites (Dunning, et al., 2011), however, indicates that the design of her own study was quite different from the Dunning study, and that her study did not even look for the kind of brain responses recorded in the Dunning study.

The Dunning study used three groups: 27 abstinent cocaine users, 28 current cocaine users, and 29 non-using control subjects. Prause used only one sample of persons: those who reported problems regulating their viewing of sexual images. Whereas the Dunning study was able to compare the responses of cocaine addicts to healthy controls, the Prause study did not compare the responses of the troubled sample with a control group.

But there is more to this slight of hand.

The Dunning study measured several different event-related potentials (ERPs) in the brain, because previous research had indicated important differences in the psychological processes reflected in the ERPs. The study separately measured early posterior negativity (EPN), thought to reflect early selective attention, and late positive potential (LPP), thought to reflect further processing of motivationally significant material. The study further distinguished the early component of LPP, thought to represent initial attention capture, from the later component of LPP, thought to reflect sustained processing. Distinguishing these different ERPs is important because differences among the abstinent addicts, current users, and non-using controls depended on which ERP was being assessed.

In contrast, the Prause study looked only at the ERP called P300, which Dunning compares to the early window of LPP. By their own admission, Prause and her colleagues report that this might not have been the best strategy:
"Another possibility is that the P300 is not the best place to identify relationships with sexually motivating stimuli. The slightly later LPP appears more strongly linked to motivation."
The upshot is that the Prause study did not in fact examine whether the brain responses of sexually troubled individuals "showed the same pattern" as the responses of addicts. They did not use the same ERP variables used in the cocaine study and they did not use an abstinent group and a control group, so they should not have compared their results to the Dunning study claiming the comparison was "apples to apples."

EEG technology limitations: Finally, EEG technology cannot measure the results the researchers claim it can. Although the researchers insist that, "Neural responsivity to sexual stimuli in a sample of hypersexuals could differentiate these two competing explanations of symptoms [evidence of addiction versus high sexual desire]," in fact it's unlikely that EEGs can do this at all. See Brainwashed: The Seductive Appeal of Mindless Neuroscience for a discussion of how EEGs can be misused to draw unfounded conclusions.

EEGs measure electrical activity on the outside of the skull, and addiction researchers who use EEGs look for very narrow signals of specific aspects of addiction. For example, this recent EEG study on Internet addicts shows how accomplished Internet-addiction neuroscientists conduct such experiments. Note that researchers isolate narrow aspects of the brain's activity, such as impulsivity, and avoid overly broad claims of the type made here by SPAN Lab. Also note the control group and pre-screening for addiction, both of which are absent in this SPAN Lab effort.

SPAN Lab seems aware of the technology's inability to distinguish among overlapping cognitive processes:
"The P300 [EEG measurement] is well known and often used to measure neural reactivity to emotional, sometimes sexual, visual stimuli. A drawback to indexing a large, slow ERP component is the inherent nature of overlapping cognitive processes that underlie such a component. In the current report, the P300 could be, and most-likely is, indexing multiple ongoing cognitive processes." (Emphasis added.)
Never mind that, by their own admission, P300 might not be the best choice for an ERP study of this type. Never mind that conducting statistical analyses with difference scores has been recognized as problematic for over 50 years, such that now alternatives to difference scores are usually used (see http://public.kenan-flagler.unc.edu/faculty/edwardsj/Edwards2001b.pdf).  Never mind that we do not really know what the amplitude of P300 to particular images relative to neutral images really signifies. P300 involves attention to emotionally significant information, but as Prause and her colleagues admit, they couldn't predict whether P300 in response to sexual images would be especially elevated for people with high sexual desire (because they experience strong emotions to sexual situations) or whether the P300 would be especially flat (because they were habituated to sexual imagery).

There is a more fundamental problem here: The Prause research team seems to want to take an either/or approach the viewing of sexual images—that ERP responses are either due to sexual desire or to an addictive problem - as if desire can be separated completely from addictive problems. Would anyone suggest that ERP responses in alcoholics or cocaine addicts might be due either entirely to their desire for the addictive substance or to their addictive problem?

Other factors can influence EEG readings. What if an image is related to a genre you like, but the pornstar reminds you of a person you dislike/fear/don't care to see naked. Your brain will have conflicting associations for such erotica. These conflicts may well be more likely in the case of porn images than in the case of, say, cocaine visuals of powder and noses (used when testing cocaine addicts).

The point is that multiple associations with a stimulus as complex as sexuality could easily skew EEG readings.

Also, SPAN Lab assumed higher EEG averages indicate higher sexual arousal, but subjects' EEG averages were in fact all over the map. Is this because some of them were addicts and others not? Or watching porn that turned them off? Many factors can affect P300 readings. Consider the following, from another P300 study:
Although the functional significance of P300 is still debated1, 2, its amplitude indexes the allocation of resources for the evaluation of stimuli....Reduced P300 amplitude has been reported in many psychiatric disorders, including schizophrenia4, depression5, and alcoholism6
In short, SPAN Lab's hypothesis that brains of addicts will show either evidence of addiction or evidence of "high sexual desire" is uninformed. Yet the abstract creates in the reader the impression that the study's results will show us that these hypersexuals either exhibited (1) evidence of addiction or (2) a positive correlation with "high sexual desire." And the study's title then misleadingly proclaims "sexual desire" the winner.

Conclusion


Quite apart from the researchers' splitting a standardized test in order to construct a correlation, no responsible scientist would argue that a study on brain waves, with no control group and no pre-screening for addiction, tells us anything about the existence or absence of addiction or "non-pathological high sexual desire" in subjects suffering from uncontrolled Internet porn use.

One must ask why the study's authors created the abstract's lengthy (misleading) preamble implying they are going to reveal evidence that calls into question the existence of sexual behavior addiction. After all, sexual behavior addiction is a condition that the American Society of Addiction Medicine's 3000+ doctors and researchers publicly affirmed in 2011 based on decades of corroborating neuroscience (including dozens of brain studies on Internet addiction). It seems likely that the current abstract was carefully composed to create the impression in hasty readers (and eager bloggers) that the researchers had somehow "disproven that sexual behavior addictions exist."

Basing far reaching conclusions on dyadic interest alone, while claiming to measure "sexual desire," is a classic bait-and-switch tactic, unworthy of PhDs from UCLA (and elsewhere). 
_____________________________________

UPDATE: Nicole Prause TV interview doesn't match study results


As a psychology professor pointed out,
In this TV interview Nicole Prause totally contradicts one of her findings. I've transcribed that portion:
Reporter: "They were shown various erotic images, and their brain activity monitored."
Prause: "If you think sexual problems are an addiction, we would have expected to see an enhanced response, maybe, to those sexual images. If you think it's a problem of impulsivity, we would have expected to see decreased responses to those sexual images. And the fact that we didn't see any of those relationships suggests that there's not great support for looking at these problem sexual behaviors as an addiction."
The written story under the TV window has a section on the UCLA press release that says essentially the same thing:
"'If they indeed suffer from hypersexuality, or sexual addiction, their brain response to visual sexual stimuli could be expected to be higher, in much the same way that the brains of cocaine addicts have been shown to react to images of the drug in other studies,' a UCLA press release on the study explained.
And yet, that did not happen."
But it did happen! The study DID show a much higher amplitude P300 for the erotic images, compared to the other images. So what Prause says in the interview doesn't match the study results.
___________________________________

 Update two

 A peer-reviewed rebuttal of the Prause paper.


Two more articles taking a look at the SPAN Lab study: 
_______________________________________

 Readers may also be interested in our critique of a related SPAN Lab effort using some of the same subjects: No Evidence of Emotion Dysregulation in “Hypersexuals” Reporting Their Emotions to a Sexual Film.

1 comment:

  1. The following comment is under this Psychology Today post interview with Nicole Prause about the above study - http://www.psychologytoday.com/blog/the-sexual-continuum/201307/new-brain-study-questions-existence-sexual-addiction/comments

    ------------------------

    A gap in logical inference

    Submitted by John A. Johnson, Ph.D. on July 19, 2013 - 11:35am.

    Mustanski asks, "What was the purpose of the study?" And Prause replies, "Our study tested whether people who report such problems [problems with regulating their viewing of online erotica] look like other addicts from their brain responses to sexual images."

    But the study did not compare brain recordings from persons having problems regulating their viewing of online erotica to brain recordings from drug addicts and brain recordings from a non-addict control group, which would have been the obvious way to see if brain responses from the troubled group look more like the brain responses of addicts or non-addicts.

    Instead, Prause claims that their within-subject design was a better method, where research subjects serve as their own control group. With this design, they found that the EEG response of their subjects (as a group) to erotic pictures was stronger than their EEG responses to other kinds of pictures. This is shown in the inline waveform graph (although for some reason the graph differs considerably from the actual graph in the published article).

    So this group who reports having trouble regulating their viewing of online erotica has a stronger EEG response to erotic pictures than other kinds of pictures. Do addicts show a similarly strong EEG response when presented with their drug of choice? We don't know. Do normal, non-addicts show a response as strong as the troubled group to erotica? Again, we do not know. We don't know whether this EEG pattern is more similar to the brain patterns of addicts or non-addicts.

    The Prause research team claims to be able to demonstrate whether the elevated EEG response of their subjects to erotica is an addictive brain response or just a high-libido brain response by correlating a set of questionnaire scores with individual differences in EEG response. But explaining differences in EEG response is a different question from exploring whether the overall group's response looks addictive or not. The Prause group reported that the only statistically significant correlation with the EEG response was a negative correlation (r=-.33) with desire for sex with a partner. In other words, there was a slight tendency for subjects with strong EEG responses to erotica to have lower desire for sex with a partner. How does that say anything about whether the brain responses of people who have trouble regulating their viewing of erotica are similar to addicts or non-addicts with a high libido?

    ReplyDelete