6 - sexual function and sex-related disorders

Question 1

how does sexual behaviour vary?

Answer 1

inter-individual variation: across individuals, cultures and time

intra-individual variation: within individuals e.g. age & development

Question 2

what are neural mechanisms underlying sexual behaviour in males?

Answer 2

medial preoptic area of hypothalamus seems critical for male copulatory behaviour

lesions of the MPAO abolish such behaviours in, stimulation elicits them

Question 3

what are neural mechanisms underlying sexual behaviour in females?

Answer 3

ventromedial nucleus critical for the display of female copulatory behaviour

electrical stimulation of the VMN facilitates lordosis (arching of back) in response to a male

Question 4

features of the Kinsey reports

Answer 4

taxonomy of human sexual behaviour based on 1000s of interviews

studies types/frequency of certain behaviours in the population

1940s-50s, provocative at the time

Question 5

features of Masters and Johnson study

Answer 5

detailed study of human sexual behaviour and disorders, 1950s-60s

measured aspects of sexual intercourse and masturbation in lab setting

established 4-stage model called the sexual response cycle (desire, plateau, orgasm, resolution)

Question 6

how has sexual orientation been studied?

Answer 6

animal models - interference with sexual differentiation can lead to displays of sexual behaviours associated with opposite sex, and to same-sex preferences

but translation to humans is limited

Question 7

what is the fraternal birth order effect (FBOE)?

Answer 7

fraternal birth order is associated with male homosexuality

more brothers - more likely to be homosexual

15-29% of homosexual men may owe their sexual orientation to this effect

robust across different cultures

relates to maternal factors because affect remains if older brothers raised in different households, but not for step-brothers

Question 8

criticisms of FBOE

Answer 8

meta-analysis found the association is small, heterogenous in magnitude (sometimes no effect), not specific to meant

existing research evidence is exaggerated by small-study effects

Question 9

what are possible hormonal factors effecting sexual orientation?

Answer 9

some evidence that perinatal hormone exposure in humans can modulate sexual preferences

Question 10

what are possible genetic factors effecting sexual orientation?

Answer 10

some evidence for a moderate genetic influence: up to 40% of variance for males and 20% for females may have genetic basis

genome wide association found specific genetic markers associated with sexual orientation, but none were predictive of sexual orientation

Question 11

what are neuroanatomical factors effecting sexual orientation?

Answer 11

specific hypothalamic nuclei may play a role in sexual preferences

differences in size of nuclei between homosexual/heterosexual males/females

Question 12

what causes deviation from social norms?

Answer 12

subjective perceptions of norms often differ from actual norms

cultural and historical variation

political influences

Question 13

how is distress measured regarding sexual pathology?

Answer 13

focus on emotional/psychological well-being

persistence or frequency of distress may be important

requires awareness and acknowledgement that some individuals may not experience distress

social norms and the protection of others

Question 14

what is sexual dysfunction?

Answer 14

relates to problems with experiencing the human sexual response cycle

Question 15

what are paraphilia disorders?

Answer 15

relates to ‘inappropriate’ activation of the human sexual response cycle

satisfaction must entail either distress/harm to the individuals, or another person

Question 16

what is gender dysphoria?

Answer 16

unhappiness due to disparity between an individual’s assigned gender and perceived gender

Question 17

what is required for diagnosis of sexual dysfunction?

Answer 17

subjective distress
impact on functioning e.g. relationships

symptoms must be persistent or recurrent

Question 18

risk factors, causes and treatments for sexual dysfunction

Answer 18

risk factors - gender, health conditions, sexual abuse

causes - psychological and/or biological

treatments - symptom focused, psychotherapy, biological (drugs or devices)

Question 19

risk factors, causes and treatments for paraphilic disorders

Answer 19

risk factors - male, hyper sexuality, past sexual abuse

causes - possible psychodynamic, but also cognitive or biological factors

treatments - behavioural techniques, cognitive therapies, hormonal or drug treatments

Question 20

requirements for gender dysphoria diagnosis

Answer 20

marked and persistent cross-gender identification

significant distress or impairment

lack of physical intersex condition

Question 21

what is a psychobiological model that accounts for gender dysphoria?

Answer 21

gender identity development passes through 4 stages:

1. chromosomal gender
2. phenotypic gender
3. brain gender
4. experienced gender

Question 22

what are issues with the psychobiological model of gender dysphoria?

Answer 22

downplays environmental and brain plasticity aspects

binary in nature: does not include consideration of non-binary gender identity

causality regarding brain differences not well-established by evidence

Question 23

risk factors, causes and treatments of gender dysphoria

Answer 23

risk factors - some evidence that paternal relationship and childhood abuse may be factors, evidence for heritability

treatments - psychological treatments (behavioural and cognitive), gender reassignment surgery