tag:blogger.com,1999:blog-21605329.post114713339499199427..comments2024-03-22T00:30:09.536-07:00Comments on The Neurocritic: Sweat, Urine, and Sexual OrientationThe Neurocritichttp://www.blogger.com/profile/08010555869208208621noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-21605329.post-89014254952075611262011-01-19T03:38:27.977-08:002011-01-19T03:38:27.977-08:00Can Humas detect pheromones?
http://dmohankumar.wo...Can Humas detect pheromones?<br />http://dmohankumar.wordpress.com/2010/12/18/human-pheromones/Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-21605329.post-1148366148598298402006-05-22T23:35:00.000-07:002006-05-22T23:35:00.000-07:00More musings:(2B) ...differing levels of hormones ...More musings:<BR/><BR/>(2B) ...differing levels of hormones in people of different sexual orientations?<BR/><BR/>There's a <B>lot</B> more on that topic; many of the recent studies use the relative lengths of the 2nd and 4th fingers as a proxy for prenatal testosterone levels:<BR/><BR/>McFadden D, Loehlin JC, Breedlove SM, Lippa RA, Manning JT, Rahman Q. (2005). <A HREF="http://dx.doi.org/10.1007/s10508-005-3123-9" REL="nofollow">A reanalysis of five studies on sexual orientation and the relative length of the 2nd and 4th fingers (the 2D:4D ratio)</A>. <I>Arch Sex Behav.</I> 34:341-56.<BR/><BR/>How this may (or may not) relate to adult hormone levels doesn't seem to be on the agenda (or at least it wasn't discussed in the review article).<BR/><BR/>Savic et al. state in the <A HREF="http://dx.doi.org/10.1073/pnas.0600331103" REL="nofollow">PNAS article</A> that hormone levels (LH, FSH, prolactin, testosterone) were normal in their lesbian population.<BR/><BR/>(3) Here I'll point out a caveat mentioned by the authors, and one I wondered about: PET can't really resolve different hypothalamic nuclei.<BR/><BR/>"The centers of the hypothalamic clusters in He[tero]M and He[tero]W were ~10 mm apart. Because registration and repositioning of PET clusters on individual reformatted magnetic resonance images revealed similar locations in all subjects and no systematic shifts between the groups, attention was paid to the more precise location of the respective local maxima. It should, however, be emphasized that their relationship to the specific hypothalamic nuclei should be viewed with caution and that the localization of atlas coordinates to a specific hypothalamic nucleus does not imply that only this nucleus was activated. Rather, it indicates that an area of 10mm around this coordinate was maximally involved."The Neurocritichttps://www.blogger.com/profile/08010555869208208621noreply@blogger.comtag:blogger.com,1999:blog-21605329.post-1148341623814091222006-05-22T16:47:00.000-07:002006-05-22T16:47:00.000-07:00Here are some musings on Dan's questions:(1) Oooh,...Here are some musings on Dan's questions:<BR/><BR/>(1) Oooh, the human VNO... I don't know anything about that. I defer to this review article:<BR/><BR/>Michael Meredith<BR/><A HREF="http://chemse.oxfordjournals.org/cgi/content/full/26/4/433" REL="nofollow">Human Vomeronasal Organ Function: A Critical Review of Best and Worst Cases</A><BR/>Chem. Senses 26: 433-445, 2001<BR/><BR/>The human vomeronasal organ (VNO) has been the subject of some interest in the scientific literature and of considerable speculation in the popular science literature. A function for the human VNO has been both dismissed with ridicule and averred with conviction. This question of VNO function has been needlessly tied to the separate question of whether there is any place for pheromone communication among humans, a topic that is itself bogged down in conflicting definitions. This review is an attempt to weigh the evidence for and against human VNO function, to deconvolve that question from the question of pheromone communication and finally to provide a working definition of ‘pheromone’. Further experimental work is required to resolve the conflicting evidence for and against human VNO function but chemical communication does appear to occur among humans. However, several examples reported in the literature do not meet the proposed definition for communication by pheromones: ‘chemical substances released by one member of a species as communication with another member, to their mutual benefit’.<BR/><BR/>(2a) Imaging data to show what happens in hetero/homo male and female brains during arousal: it's not out there. The Neurocritic found 3 papers that directly compared brain activity in heterosexual men and heterosexual women viewing porn clips. In one of these, men showed greater activation in the amygdala and hypothalamus, even when women reported greater arousal [Hamann S, Herman RA, Nolan CL, Wallen K (2004) <A HREF="http://dx.doi.org/10.1038/nn1208" REL="nofollow">Men and women differ in amygdala response to visual sexual stimuli</A>. <I>Nature Neurosci </I>7:411–416]. Another paper reported greater hypothalamic activation in men than women [Karama S, Lecours AR, Leroux JM, Bourgouin P, Beaudoin G, Joubert S, Beauregard M. (2002). <A HREF="http://dx.doi.org/10.1002/hbm.10014" REL="nofollow">Areas of brain activation in males and females during viewing of erotic film excerpts</A>. <I>Hum Brain Mapp.</I> 16:1-13], but a more recent experiment by the same group did <EM>not</EM> find a difference between men and women in the hypothalamus [Gizewski ER, Krause E, Karama S, Baars A, Senf W, Forsting M. <A HREF="http://dx.doi.org/10.1007/s00221-006-0429-3" REL="nofollow">There are differences in cerebral activation between females in distinct menstrual phases during viewing of erotic stimuli: a fMRI study</A>. <I>Exp Brain Res.</I> 2006 Apr 8].<BR/><BR/>Gizewski et al. say, "According to common sense women should have greater sexual arousal during the mid-luteal phase but contradictory results in the literature are reported (Karama et al. 2002). Due to hormonal influences on sexual arousal, we assumed differences in brain activation during the emotional task of viewing erotic film excerpts. Therefore, in the present study, only women in midluteal phase were entered into the experimental group<BR/>and were measured again during menstrual phase vice versa respectively according to randomization. We revealed superior activation for women in mid-luteal phase in the anterior cingulate, the left insula, and left orbitofrontal cortex compared to women in menstrual phase." [NOTE: but no difference in hypothalamus]<BR/><BR/>and<BR/><BR/>"This study cannot clarify the relationship between hormonal influences on the one hand and sexual arousal and patterns of brain activation on the other, as interactions between social and hormonal influences have to be considered (Breedlove et al. 1999)."The Neurocritichttps://www.blogger.com/profile/08010555869208208621noreply@blogger.comtag:blogger.com,1999:blog-21605329.post-1148003914363468482006-05-18T18:58:00.000-07:002006-05-18T18:58:00.000-07:00Thanks, Dan. Too bad that things like finals and p...Thanks, Dan. Too bad that things like finals and papers (and grant progress reports and manuscript submissions) keep us from blogging! I'm behind on my posts this week, but I'll get to your interesting questions soon.The Neurocritichttps://www.blogger.com/profile/08010555869208208621noreply@blogger.comtag:blogger.com,1999:blog-21605329.post-1147919416358221682006-05-17T19:30:00.000-07:002006-05-17T19:30:00.000-07:00By the way, I think Peter Brunjes, (one of my prof...By the way, I think Peter Brunjes, (one of my profs at UVA. Brilliant. Does olfaction and he's funny as hell, too), would like these posts. I will send him over if I can get in touch with him.Dan Drighthttps://www.blogger.com/profile/12106833469192726144noreply@blogger.comtag:blogger.com,1999:blog-21605329.post-1147919222591006572006-05-17T19:27:00.000-07:002006-05-17T19:27:00.000-07:00I have a few questions:1. Although mammals have a ...I have a few questions:<BR/><BR/>1. Although mammals have a specific vomeronasal organ (fed by the palatine nasal duct, I think) nobody has ever been able to find one in humans.<BR/><BR/>2. Where is the imaging data to show what happens in hetero/homo male and female brains during arousal generally? Is this at all related to "sex" per se, or just to differing levels of hormones in people of different sexual orientations?<BR/><BR/>3. I guess it seems to me that the sexual orientation of the participants is being conflated with the meaning of the imaging data.<BR/><BR/>Nice post. Keep up the good work.<BR/><BR/>PS: I put a link to your fabulous blog up after a spell of bloggy inactivity caused by finals and papers.Dan Drighthttps://www.blogger.com/profile/12106833469192726144noreply@blogger.com