Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

The Releasing Stimuli for Sex

What examples of visual releasing stimuli do we have?

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  Rhesus monkeys pay for sexual imagery of female rhesus monkeys (esp the perineum of a female in estrus). Also pay to see a dominant male - might be "gathering information."
  
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  Both sexes in humans have the amygdala, hypothalamus, and mesolimbic dopamine systems activated when viewing a picture of somebody they find sexually attractive.
  

Tactile stimuli?

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  Lordosis!
  
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  Also skin can be more sensitive if and only if you have certain levels of gonadal hormones.
  
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  Touch evokes activation of dopamine systems
  

Olfactory stimuli?

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  Pheromones! They're breakdown products of sex hormones. What can you know by smelling them?
  
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    Gender, age, fertility, reproductive state
    
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  What do you need to detect them?
  
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    Intact gonads
    
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  What are the intrasexual effects of pheromones?
  

Gustatory stimuli?

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  Some ungulates do flehmening where they lick each other's genitals to gain the pheromonoal information.
  

Auditory stimuli

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  A stag's roar can induce ovulation in females.
  
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  Pandas and human females have slightly higher pitched voices around ovulation
  

OTHER stimuli?

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  Thought: like fantasy in humans (and Sapolsky would say in his baboon observation)
  
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  Rage/fear/stress: inhibit sexual behavior and physiology Variety and the Coolidge effect.
  

Sexual Behavior (lecture 2 of 2)

How Hormones in Adulthood Affect Sexual Behavior

First: note what we mean by "sexual behavior."

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  Proceptive, receptive, attractive behavior.
  
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  Erections, pelvic thrusts, lordosis, likelihood of orgasm, interest in sex, etc.
  

Second: note what we mean by organizational vs. activational effects

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  Organizational: perinatal environmental hormones. Setting up the framework and the structuring for the whole life.
  
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  Activational: acute hormonal effects in adulthood. Immediate triggers.
  

Where in the menstrual cycle does sexual behavior peak in most female animals? In humans?

• Most animals: peaks at ovulation. Sometimes only occurs at ovulation.

• Humans: same thing, but also get a peak at menstruation, hypothesized to be due to "relief" at not having gotten pregnant.

What effects are female hormones having?

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  Estrogen works in brain to increase progesterone and oxytocin receptors in the limbic system.
  
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  Skin more sensitive to touch
  
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