sexual function and disorders

Question 1

why is it difficult to study sex behaviours

Answer 1

remains private for most
wide range of specific behaviours
diverse across individuals, cultures, and time
varies within individuals - age, life events, circumstances

Question 2

how has neural basis been studied for sex behaviours

Answer 2

in rats

Question 3

sex behaviours - hypothalamus in males

Answer 3

males = medial preoptic area (MPAO) for copulatory behaviours (mounting, intromission, ejaculation)

lesions abolish these behaviours (and can in females where some are also observed)

stimulation of MPAO elicits these behaviours

Question 4

sex behaviours - hypothalamus in females

Answer 4

females = ventromedial nucleus (VMN) for copulatory behaviours (lordosis)

stimulation of VMN facilitates lordosis in response to a male

Question 5

Complexity of sexual behaviour beyond neural mechanisms - in humans and mice

Answer 5

yes
complex sensory input and cortical and subcortical systems conveying contextual rewards-related and motivational info

e.g. mice sing to each other

e.g. chemical in tears of juvenile mice deters female mice from them

humans - comparative thinking about sexual behaviour

Question 6

early studies of human sexual behaviour - Alfred Kinsey

Answer 6

Alfred Kinsey (1940-50s) - the Kinsey Reports

taxonomy of human sexual behaviour (based on interviews)

study of types and frequencies of behaviours in population

→ shocking at the time

Question 7

early studies of human sexual behaviour - Masters and Johnson

Answer 7

study of human sexual behaviours and disorders in 50s/60s

measured sex and masturbation in a lab

established 4 stage model for human sex behaviour → sexual response cycle

Question 8

Sexual Response Cycle - 4 stages

Answer 8

desire, plateau, orgasm, resolution

male-female difference –> male orgasm once, women can multiple times

Question 9

recent studies of human sexual behaviours

Answer 9

refined terminology and identified variability in normal cycles - building off of sexual response cycle - desire, arousal, plateau, orgasm, refraction

attempts to determine neuroanatomical correlates of components of the cycle

3 major components: wanting, liking, learning

fMRI studies of sexual function found differences in brain in difference phases

Question 10

sexual orientation

Answer 10

relates to biological sex, gender identity, and sexual behaviour

sexual identity = aspects of both gender identity and sexual orientation

Question 11

animal models of sexual orientation

Answer 11

interference with sexual differentiation (e.g. blocking hormones, lesioning hypothalamic nuclei) can lead to displays of behaviours related with opposite sex and same-sex preferences

cannot translate well to humans - is it valid in studying sexual orientation

Question 12

FBOE

Answer 12

fraternal birth order effect
more older brothers = boys more likely to be gay

15-29% of gay men follow this effect

remains across different cultures

older sisters or younger siblings have no effect on sexual orientation - just older brothers

effect remains if older brothers raised in different households but doesn’t remain with older step brothers or adopted brothers

implies effect relates to maternal factors

maternal immunization hypothesis
* antibodies in mother after having a boy which pass on to next child and effect sexual orientation

meta-analysis found evidence was not specific to men and effect size varied greatly - small study effects

Question 13

sexual orientation research - perinatal hormone exposure

Answer 13

limited evidence that perinatal hormone exposure can modulate same-sex/opposite sex preferences

Question 14

sexual orientation research - hypothalamic nuclei

Answer 14

some evidence that hypothalamic nuclei may play a role in sexual preference → size differences of nuclei in hetero vs homosexual men and women

Question 15

sexual orientation research - family/twin studies

Answer 15

some family/twin studies for moderate genetic influence on sexual orientation

up to 40% of variance in sexual orientation of males and 20% of variance in sexual orientation of females may have genetic basis

Question 16

sexual orientation research - genetic markers

Answer 16

specific genetic markers associated with sexual orientation

determined none were predictive of sexual orientation - no “gay gene”

therefore genetic component is multidimensional and complex

Question 17

defining what is normal - different measures

Answer 17

deviation from statistical norms
deviation from social norms
distress
deficits in normal function

Question 18

defining what is normal - deviation from statistical norm

Answer 18

somewhat arbitrary in terms of usefulness and classification

relies on extensive and accurate data - hard to obtain

cross-cultural granularity

ultimately remains subjective

Question 19

defining what is normal - deviation from social norms

Answer 19

influence on social judgement

socially normal isn’t always adaptive/functional

subjective perception of norms can differ from actual norms

cultural and historical variation - political influences

circularity → norms create pathology as well as define it

Question 20

defining what is normal - distress

Answer 20

focus on emotional/psychological well-being

persistence/frequency of distress may be important

needs awareness and acknowledgement that some individuals don’t experience distress

social norms and protection of others - laws

Question 21

defining what is normal - deficits in normal function

Answer 21

focus on social, interpersonal, occupational functioning

e.g. can’t develop/maintain loving relationship

some responses can have reasonable basis - e.g. abuse - and so need to avoid pathologising

can cut across individual life choices

ignore individual experience/impact

interacts with social norms

Question 22

define sexual dysfunction

Answer 22

relates to problems with experiencing the human sexual response cycle

Question 23

define paraphilic disorders

Answer 23

relates to inappropriate activation of the human sexual response cycle

“Any intense and persistent sexual interest, other than sexual interest in genital stimulation or preparatory fondling with phenotypically normal physically mature, consenting human partners” - DSM-V

Question 24

define gender dysphoria

Answer 24

unhappiness due to perceived gender differing from assigned gender

Question 25

sexual dysfunction - typeswith cycle

Answer 25

types categorised according to phases of human sexual response cycle:

desire → male hypoactive sexual desire disorder

plateau → female sexual interest/desire disorder, erectile disorder

orgasm → female orgasmic disorder, delayed ejaculation, early ejaculation

resolution → sexual pain disorders

Question 26

sexual dysfunction: diagnosis, risk factors, causes, and treatments

Answer 26

diagnosis - must be impact on subjective distress and functioning (e.g. relationships) with persistent and recurrent symptoms. more common in females (may be gender bias in reporting)

risk factors = gender related, health conditions, sexual abuse

causes = psychological or biological can be hard to determine (concerns with over pathologising inter and intra individual differences)

treatments = symptom focussed, psychotherapy or drugs/devices

Question 27

paraphilic disorders - types in 3 categories (2,4,2)

Answer 27

not directed at another person:
fetishistic disorder
transvestic disorder

directed at non-consenting person:
exhibitionistic disorder
frotteuristic disorder (touching)
pedophilic disorder
voyeuristic disorder

involves experiencing or inflicting suffering:
sexual masochism disorder
sexual sadism disorder

ideas of how the law interacts with this

Question 28

paraphilic disorder - diagnosis, risk factors, causes, treatments

Answer 28

diagnosis = satisfaction must entail either distress/harm to individual or another person

risk factors = being male, hypersexuality, for paedophilia = past sexual abuse, attachment issues, substance abuse comorbidity

causes = very little understood - possible psychodynamic but could also be cognitive or biological (most research done on paedophilic disorder

treatments = behavioural techniques, cognitive therapies, hormonal and drug treatments

Question 29

gender dysphoria - diagnosis and incidence

Answer 29

previously called gender identity disorder

diagnosis = marked and persistent cross-gender identification, significant distress/impairment, lack of physical intersex condition (other treatments for this)

can be diagnoses in children - though most wont have a condition as adults

incidence estimates vary - relatively rate, 0.01% males and even rarer in females - recent evidence for 1% of population experiencing some level of gender incongruency

comorbid with anxiety and depression

Question 30

gender dysphoria - psychobiological model (and issues)

Answer 30

neurobiological basis which is closely associated with interaction with external world

introduced concept of brain gender

chromosomal gender -> phenotypic gender -> brain gender -> experienced gender

issues:
* goes against evidence for no male/female brain difference
* downplays environmental and brain plasticity aspects
* binary nature
* causality regarding brain differences isn’t well established in evidence

Question 31

gender dysphoria - risk factors and causes

Answer 31

evidence base and understanding relatively weak

some evidence indicates that paternal relationship (for males) and childhood abuse (for females) may be factors

little support for notion that parental attitudes or behaviours play a role

biological factors may include in-utero hormone exposure

mixed evidence for differences in brain structures

evidence from twin studies for heritability, though no single gene has been found

Question 32

gender dysphoria - treatments

Answer 32

psychological treatments (behavioural and cognitive) - some success but clients often resistant (understandably)

gender reassignment surgery – often leads to satisfactory outcomes but may not alleviate other psychological co-morbidities