PSY 250 Lecture Notes - Lecture 26: Dihydrotestosterone, Gender Variance, David Reimer
Garrett: Brain & Behavior, 3e
1
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!"#$%&'(89%/-5&(#56(:&1(+&';<(
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1. Sex&as&a&form&of&motivation&
a. Similar&to&hunger&and&thirst&drives,&but&failure&to&satisfy&drive&does¬&lead&to&death&
b. Arousal&and&satiation&
i. Sexual&response&cycle&includes&excitement,&increasing&to&plateau,&peaking&during&
orgasm,&and&declining&during&the&resolution&phase&
ii. Afterward,&males&typically&cannot&engage&in&sex&for&some&time,&called&refractory&
phase&
iii. !../-60&(&22&=%>&quick&return&to&sexual&arousal&when&a&new&partner&is&
introduced&
c. Role&of&testosterone&
i. Sexual&behavior&usually&a&result&of&sexual&hormones&
ii. !#<%'#%-.5,&removal&of&the&gonads,&is&a&technique&to&find&role&of&sexual&
hormones&by&removing&their&sources&
1. >56'.0&5<&are&responsible&for&male&characteristics&and&functions&
2. +&<%.<%&'.5&&is&the&major&male&sex&hormone&
iii. Estrus&is&the&period&when&females&ovulate,&sex&hormones&are&high,&and&animal&is&
said&to&be&in&heat&
1. ?<%'.0&5&is&a&class&of&hormones&responsible&for&female&characteristics&
and&functions&
2. In&human&females,&estrogen&peaks&14&days&before&monthly&
menstruation;&peak&is&correlated&with&female>initated&sexual&activity&
d. Brain&structures&and&neurotransmitters&implicated&in&sexual&activity&
i. @&6-#/($'&.$%-=(#'&#(A@B8>C(of&hypothalamus&involved&in&male&and&female&
sexual&behavior&
ii. @&6-#/(#;106#/#&contributes&to&sexual&behavior&in&both&sexes,&as&well&as&being&
involved&in&aggression&and&emotion&
iii. 3&49#//1D6-;.'$"-=(59=/&9<(A3EFC>&a®ion&of&the&MPOA&is&five×&larger&in&
males&and&is&involved&in&male&sexual&performance&
iv. G&5%'.;&6-#/("1$.%"#/#;9<(is&important&for&female&sexual&behavior&
v. During&Coolidge&effect&dopamine&increases.&
vi. During&ejaculation,&serotonin&levels&increase&in&the&lateral&hypothalamus&
e. Odors,&Pheromones,&and&Sexual&attraction&
i. Nose&as&a&sex&organ&
1. @#H.'("-<%.=.;$#%-I-/-%1(=.;$/&4(A@J!C&is&a&group&of&genes&that&
contributes&to&immune&system&functioning,&and&affect&odors&that&are&
avoided&in&related&individuals&
2. B"&'&;.5&<&are&bioactive&chemicals&released&by&individual&which&
change&the&behavior&or&physiology&of&others,&such&as&those&involved&in&
sexual&attraction&in&moths&and&cats&
3. The&K.;&'.5#<#/(.'0#5(AGF8C,&a&cluster&of&receptors&in&the&nasal&cavity,&
detect&pheromones.&Evidence&suggests&such&an&organ&is&present&in&most&
if¬&all&mammals.&
4. 841%.=-5,&a&neuropeptide,&facilitates&bonding&and&milk&ejection&in&
animals.&Also&released&during&sexual&activity.&
Document Summary
Chapter outline and key terms: sex as a form of motivation, similar to hunger and thirst drives, but failure to satisfy drive does not lead to death, arousal and satiation, sexual response cycle includes excitement, increasing to plateau, peaking during orgasm, and declining during the resolution phase, afterward, males typically cannot engage in sex for some time, called refractory phase, coolidge effect quick return to sexual arousal when a new partner is introduced, role of testosterone, sexual behavior usually a result of sexual hormones, castration, removal of the gonads, is a technique to find role of sexual hormones by removing their sources, androgens are responsible for male characteristics and functions, testosterone is the major male sex hormone, estrus is the period when females ovulate, sex hormones are high, and animal is said to be in heat, estrogen is a class of hormones responsible for female characteristics and functions.
