Exam 3 Flashcards
Polygyny
1 male mating with multiple females ( most common in the animal kingdom)
Species with high polygyny
Chimpanzees
- Complex social species. Chimp troop consists of up to 100 individuals with 3-4 high ranking males which dominate.
Species with monogamy
Gibbins Titi monkey (father do more)
Species with high polygamy cont.
Gorillas have a polygynous mating system
Alpha male (silverback) with a harem of females
- Males control access to females through
Agression to assert dominance
-Defends access to females(protect from other males)
Size sexual dimorphism and mating systems
Greater sex difference in size for species where the mating system is polygamous
- less of a need to females to compete in polygamous systems so they stay small
Sex differences
Human men are 10-15% larger
Male Stag beetles
Male Baboons weigh twice as much
Attachment CPP
males tend to spend more time in the chamber with a paired females versus a non paired female
Oxytocin
released from the posterior pituitary into the general circulatory systems
Prairie vole vs montane vole
Prairie voles have more oxytocin receptors
Nucleus Accumbens
- Drug addiction, dopamine, pleasure etc.
- Make subjects spend time with each other, bond.
- More oxytocin= more bonded
Copulatory lock
- ejaculate then lock
- allows sperm enough time to get to egg
Activational effects of testosterone
- Testosterone regulates ejaculation
- No testosterone-> no ejaculation
Altrical
-vulnerable, underdeveloped, highly dependent on parents
Precocial
- born fully developed/advanced state
Craving
- intense infatuation and fixation on partner
Tolerance
- shift feelings- get less excitement in the relationship
Withdrawal
physiological response to a break up/ end of a relationship
Oxytocin receptor antagonist
If administered in the nucleus accumbens would spend more time with stranger- prefer the novelty
Appetitive behavior
- Courtship
- Operant
- Approach
Bonobo G-G rubbing
Mother and Daughter- social behavior/ enhance bond
sexual and social aspects to G-G rubbing
Consumatory behavior
engaging in sexual behavior/ including brain regions involved.
4 aspects of consummatory behaviors
Copulatory lock
Thrusting
Multiple intromissions
Multiple ejaculations
Genital swelling
correlated with the process of ovulation=tells males that reproduction is more likely to occur
Sexual partner ( rodent model)
- Lever press for access to a sexual partner
- Runway model- run faster for a sexual partner
Castration Sex
- Pre castration- males have sex
- Castration- sex declines
- Readministration- sexual behavior gets reinstated
Castration for sex offenders?
- Chemical castration, massively limit testes activities
- no before results, participants in prison
Hypogonadism
HPG does not work effectively, low levels of testosterone
- Treatment: administration : administer testosterone
-(1 group gets t, placebo, higher dose of t)
Men with placebo engage in less sexual behavior
- T works on both appetitive and consummatory behavior
Coolidge effect
- Novelty increases sexual behavior in the same rat
- Introduce a new female/ male will ejaculate again
Mesolimbic dopamine pathway(VTA-> nucleus accumbent)
- Involved in sexual reward and desire
- Microdialsys showed increase dopamine release when a male is exposed to a female/ but with a barrier. Biggest spike in dopamine occurs during copulation.
female from heaven
- lever pressing is appetitive
- lesion amygdala, less lever pressing
- lesion prep-tic nucleus hypothalamus press at the same rate
- lesion to the hypothalamus decreases consummatory behavior
- lesions to amygdala no decrease in consummatory
- castration decrease lever pressing and consummatory behavior
The amygdala and hypothalamus
have a high density of androgen receptors
Coolidge effect
- Female does hop dart and wiggle, male will ejaculate and over and over again
- After each episode it takes longer and longer
- Eventually will stop showing responsiveness to female after 5-6
- However sexual desire and arousal introduced by novel females.
Image male brain during ejaculation
- Male lay down, female stimulation to ejaculation
- VTA= ventral tegmental area activated (goes to nucleus acombas) sexual reward
Induced ovulation
animals that only ovulate when they are having sex
receptivity in rats
F rats only engage in lordosis in bx estrus
F Rats need flank stimulation to trigger lordosis
Also need estradiol binding to VMM (ventromedial nucleus). This most impo for females
For males most impo medial preoptic nucleus
Perceptivity
behavior enacted by a female to initiate, maintain, or escalate a sexual interaction.
Attractiveness
The stimulus value of a female to a potential mate
Sexual motivation
female’s desire to engage in copulatory activity
sexual motivation in rats
-Females like to control mating
-Gets more pleasure from pacing than non pacing and no male
Pacing happens bc coolidge effect
attractiveness in rats
Measure how long it takes for the male run towards
A critical features of why a male runs to run faster is mediated by estradiol and progesterone which causes female to release pheromones
Follicular phase
-To develop a series of follicles within the ovaries(under developed eggs- cells that need to grow to become eggs)
-Cell burst- release egg
-Hypothalamus release GnRH- pulse release(pulse generation)
-Causes pituitary to release LH and FSH in a pulsicular release
-FSH signals follicles to grow and mature
Usually one egg released through maturation process
As follicles mature they release estradiol
-Estradiol serves a negative feedback loop to stabilize the release of GNRH and FSH/LH
Luteal phase
- approximately day 15 to 29 of the cycle (relatively stable length of time)
- The ruptured follicle becomes the corpus luteum
- The corpus luteum- primarily going to be producing progesterone
- Secreting progesterone- to give nutrients(build up) the uterine lining
- Progesterone levels crash during the late luteal phase- the signal to initiate mensis
Birth Control
Most common contain( estrogen and progesterone)
If you take high doses of these hormones-> they will suppress the HGP axis through negative feedback system
Symmetry
-Women show increased preference for symmetry during ovulation
-Fluctuating symmetry is bad
More symmetrical more lifetime sexual partners
-Greater variance in men’s sexual partners compared to women
What is the function of symmetry?
symmetry= health
Have stronger immune systems
Rate symmetrical faces as healthier
The scent of Symmetry: A Human Sex Pheromone that Signals Fitness?
FERTILE WOMEN- rate smell of symmetrical men as higher
(women only get access to t-shirt with smell)
Signaler pheromone???
Masculinity
Researchers: masculinize and feminize the same face
Masculinity is a cue of testosterone- bc testosterone masculinizes the face/body
During ovulation- women prefer masculine to feminine faces
Masculinize and feminize a person’s voice
During ovulation- women prefer masculine to feminine voices
Protective- ensures do not have sex with an under developed male
Proceptivity in women
-Clothing: quantifying the amount of skin showing
Choice of clothing may feed into proceptivity- not conscious
Subjects asked to draw two different outfits: during ovulation and not during ovulation
-Sexy gait during ovulation
-Strip club experiment:More tips-> men are more attracted to them
Dancing more provocatively when fertile vs non-fertile
Increase in sexual motivation causes an increase in behavior
fertility and attractiveness
Relationship between age and physical attractiveness
-Men’s attractiveness towards women decreases around 50- which is when menopause occurs.
Maximum fertility around the early 20s
Correlation (very close link ) between fertility and attractiveness
sexual motivation in women
By looking at sexual behavior ( diary journal recording- report when engage in sexual activity)
Cons: have individuals who avoid trying to have sex during ovulation
Record Masturbation( over course of the cycle)
Cons: Different attitudes towards engaging in this sexual behavior
Sexual fantasy:
Peaking erotic activity during ovulaton
Late follicular stage
start with estradiol rising. Tells the ovaries follicle is almost ready to burst. There is a switch. From negative hpg control to positive feedback loop
Surge center. Release GnRH is at higher levels (surge). Promote surge in lh/fsh. Lh surge causes ovulation.
menstrual cycle days
Menses day 1-5
Follicular stage: approx. 6-13
ovulation 14/15
Luteal: 15-29
Adaptive function of estrus
Increases the likelihood of successful copulation and reproduction
Female HPG axis
GnRh released from hypothalamus
FSH and LH released from anterior pituitary
to the varies which release estradiol and progesterone
menses
shed uterine lining out of body
If she does not shed it, in estus, females just absorb the lining
