Psyc4130 1nd Edition Lecture 19 Outline of Last Lecture I. Turners SyndromeII. Congenital Adrenal Hyperplasia III. Secondary Sexual DevelopmentIV. Hormone Control of MensesV. ProgesteroneVI. Testosterone Fuels Libidoa. Malesb. FemalesVII. Refractory Perioda. Coolidge EffectVIII. HormonesIX. PheromonesX. AllomonesXI. The Vomoeronasal OrganXII. Pheromonal Phenom in RodentsOutline of Current Lecture I. Pheromonal Phenom in RodentsII. Pheromones in Humansa. McClintock EffectThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Human Sexual Attraction Pheromonesa. Androstadienone b. Estratetraene IV. Dimorphismsa. Aromaraseb. oSDNc. Sexual orientation and SDNV. What “Causes” Homosexuality?”Current Lecture Pheromonal Phenom in Rodents- Vandenbergh effect: in the presence of a male, puberty is accelerated- Bruce Effect: spontaneous abortion elicited when a recently-impregnated female mouse encounter- a male other than the one that impregnated her Pheromones in Humans- VNO present but vestigial - However, the main olfactory system (i.e. epithelium in humans) still appears to register the effects of certain pheromones- Are not consciously aware of the smell of pheromones, but effects the neurophysiology of the cells, not experiential - These differentially influencer sex-related behaviors in heterosexual men and women - Kissing- pheromonal compatibility - Urine- high concentration of pheromones in urine- McClintock Effect: synchronized cycles in cohabitating womeno A pheromone present in underarm sweat appears to be key (Russell et al., 1980)o It does regulate women’s cycles. Lower ranking socially female, will adjust their cycles to socially dominant female - Extracts from the sweat of men advanced the onset of the next surge in LH, reduced anxiety and increased relaxation in women (Preti et al., 2003)o Speeds up ovulation o Adaptive- only time they might get prego Human Sexual Attraction Pheromones- Androstadienone o (AND) is an adrogenic chemical shown to enhance positive affect and sexual arousal in women but to decrease positive affect in men (feel better, lift mood) “AND then…?”- Estratetraene o (EST) is an estrogenic chemical which, in men but not in women, activates hypothalamic nuclei associated with sexual responding “Go EST, young man!” Dimorphisms- To what extent are male and females brains different- today don’t see structural differences in brains- Goats- 8-10% are gay aka “ewes” (sexual behavior)o Some species of animals have been seen to have homosexual sexual behavior- Aromaraseo Turns testosterone into estrogen (defeminizes the males brain)- oSDNo Sexually dimorphic nucleus o Preoptic area o Nucleus that looks structurally different in male vs female sheep- Sexual Orientation and the SDNo Figure 10.12- sexual dimorphism and role of sexual orientation in the volume andnumber of neurons in the SDN in sheep- Hypothetically- gender identification o Bed nucleus of the stria terminalis (BNST)o BNST carries signals form centromedial amygdala to ventrical medial nucleus (VMN) of the hypothalamuso 10.13- the human BNSTo The unicate nucleus of hypothalamus is 2x in men compared to women and in females… What “Causes” Homosexuality?- “Domineering mother hypothesis” roundly discredited as an explanation of male homosexuality- Maternal stress, however, might play a role in decreasing the effectiveness of prenatal androgens (Wards, 1972)o i.e. they are less capable of defeminizing the male braino **Nothing absolutely causes it! See correlations, influenced, and factors that tend to make it more likely but not CAUSES a person to be born gay- Circulating levels of androgens in adult males is not a factor whatsoever- Genetic contribution appears significant:o 52% concordance rate for MZ twins Vs. 22% for DZ twinso Some estimates as high as 60% for MZ
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