You might have seen the news stories with their facile headlines:
Women with low libidos 'have different brains'Women with low libidos have a different mental response to intimate situations than those with a 'normal' sex drive, researchers have found. By Stephen Adams, Medical Correspondent, in Denver...and even worse:
Published: 5:59AM BST 26 Oct 2010MRI scans show that women diagnosed with what is termed hypoactive sexual desire disorder (HSDD) - defined as a distressing lack of sexual desire - have different patterns of brain activity. Certain areas of the brain that normally light up when thinking about sex fail to do so in women with HSDD, found medics at Wayne State University in Detroit, US, while other areas that don't normally light up, do.
Libido problems 'brain not mind' Scans appear to show differences in brain functioning in women with persistently low sex drives, claim researchers.The US scientists behind the study suggest it provides solid evidence that the problem can have a physical origin.[NOTE: The mind is separate from the brain? Really?? Then where is the mind located? In the big toe? The pancreas?]
Hypoactive Sexual Desire Disorder (HSDD) is a controversial diagnosis given to women who have a low (or nonexistent) libido and are distressed about it. Dr. Petra Boynton has written extensively about the problematic aspects of the HSDD diagnosis and the screening tools used to assess it, as well as the medicalization of sexuality for pharmaceutical marketing purposes.
The issue to be discussed here is the widespread press coverage given to an unpublished study presented at a conference. This is fairly standard practice, as professional organizations such as the Society for Neuroscience have a well-staffed press room where properly credentialed reporters have access to:
- Embargoed annual meeting news releases
- Lay-friendly summaries of newsworthy findings
- Press conference slides and video footage
Here's the HSDD abstract in question, from an oral presentation at the American Society for Reproductive Medicine's 66th Annual Meeting:
[O-199] CEREBRAL ACTIVATION PATTERNS IN WOMEN WITH HYPOACTIVE SEXUAL DESIRE DISORDER (HSDD) VERSUS WOMEN WITH NORMAL SEXUAL FUNCTION.
T. L. Woodard, N. T. Nowak, S. D. Moffat, M. P. Diamond, M. E. Tancer, R. Balon. Wayne State University School of Medicine, Detroit, MI
OBJECTIVE: To identify and compare cerebral activation patterns of premenopausal women with acquired HSDD versus those with normal sexual function during viewing of sexually explicit film clips.DESIGN: Prospective Cohort Study.MATERIALS AND METHODS: After IRB approval, 19 premenopausal women with HSDD and 7 women with normal sexual function were recruited to participate in the study. The diagnosis of HSDD was confirmed using the Sexual Function Questionnaire (SFQ), Female Sexual Distress Scale (FSDS) and a clinical interview. Functional neuroimaging was performed on a 4 T Siemens Bruker Hybrid Scanner while participants viewed three categories of video stimuli (solid blue screen, neutral videos, and sexually explicit videos), which alternated every 60 seconds for 32 minutes in a block design. Data were analyzed using Statistical Parametric Mapping 2 (SPM2).RESULTS: When cerebral activation patterns associated with viewing sexually-explicit videos in normal women was compared to that of women with HSDD, women with normal sexual function had greater activation in superior frontal and supramarginal gyri. Women with HSDD exhibited greater activation in the inferior frontal, primary motor, and insular cortices. Additionally, normal women had greater activation in the posterior cingulate cortex while women with HSDD appeared to recruit the midcingulate region.CONCLUSION: Cerebral activation patterns in women with HSDD differs from those in women with normal sexual function and may reflect differences in how they interpret sexual stimuli.Supported by: Wayne State University Departments of Psychiatry and Obstetrics and Gynecology.
Access to the meeting website requires registration, although one does not have to be a member of the ASRM to do so. Nonetheless, the barrier to finding this information online is rather high, and I imagine only 3 other people cared enough to do the proper searches.
Do these researchers have any peer reviewed publications related to neuroimaging studies of HSDD? There's a brief mention of fMRI and PET in one review paper (Woodard & Diamond, 2009). They also have a fun paper on how they chose their stimuli (i.e., erotic films). Q: What kind of erotic film clips should we use in female sex research? A: heterosexual vaginal intercourse.1 [See this summary by Scicurious.]
Let's return to the abstract and the major neuroimaging results:
When cerebral activation patterns associated with viewing sexually-explicit videos in normal women was compared to that of women with HSDD, women with normal sexual function had greater activation in superior frontal and supramarginal gyri. Women with HSDD exhibited greater activation in the inferior frontal, primary motor, and insular cortices. Additionally, normal women had greater activation in the posterior cingulate cortex while women with HSDD appeared to recruit the midcingulate region.The supramarginal gyrus in the parietal lobe? Yeah, that's a real sexy area of the brain. So is the superior frontal gyrus, for that matter. Neither of these brain areas are implicated in sexual arousal, so the fact that these regions showed greater activation in the 7 women with "normal" libidos seems largely irrelevant.
How about the women with HSDD? They showed greater activity in the insula, which has been implicated in feelings of disgust, but it's also been associated with interoceptive awareness of bodily states and many other functions (e.g., subjective emotional feelings, perception, cognition, performance, and attention). Moving right along (so to speak) to the motor cortex... now that's an interesting finding. Greater motor resonance or "mirroring" of action in the film clips for those with HSDD? With top-down control involving the inferior frontal cortex preventing actual movement? Mirror neurons have, in fact, been found in the primary motor cortex of monkeys (Tkach et al., 2007). These cells showed similar activity during both the execution and observation of actions. So if anything, this finding might suggest that the women with HSDD were actually more engaged while watching the erotic films!
The abstract concludes by saying "Cerebral activation patterns in women with HSDD differs from those in women with normal sexual function and may reflect differences in how they interpret sexual stimuli", which doesn't tell us very much. It seems the authors need to take their own advice from another paper (Woodard & Diamond, 2009):
Many physiologic methods [of sexual function in women] exist, but most are not well-validated. In addition there has been an inability to correlate most physiologic measures with subjective measures of sexual arousal. Furthermore, given the complex nature of the sexual response in women, physiologic measures should be considered in context of other data, including the history, physical examination, and validated questionnaires...
1 The participants in the study were:
21 women [who] have viewed pornography in the past. Informed consent was obtained. The mean age of the subjects was 31.2 ± 10.46 years (range: 18–57 years). The majority of the participants were Caucasian (66.7%) and 23.8% were black, 4.8% were Asian and 4.8% did not respond. ... With regard to sexual orientation, 76.2% [n=16] described themselves as heterosexual while 19% [n=4] were bisexual and 4.8% [n=1] were unknown.NOTE: Why include the one participant with unknown sexual orientation? Why not drop her? And don't you imagine the bisexual women might have liked some clips that were not preferred by the heterosexual women?
Tkach D, Reimer J, Hatsopoulos NG. (2007). Congruent activity during action and action observation in motor cortex. J Neurosci. 27:13241-50.
Woodard TL, Collins K, Perez M, Balon R, Tancer ME, Kruger M, Moffat S, Diamond MP. (2008). What kind of erotic film clips should we use in female sex research? An exploratory study. J Sex Med. 5:146-54.
Woodard TL, Diamond MP. (2009). Physiologic measures of sexual function in women: a review. Fertil Steril. 92:19-34.
Figure 4 (Woodard & Diamond, 2009). The Genitosensory Analyzer is used to measure temperature and vibratory sensation of the genitalia.
from Brain in a Vat.
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