PSYC 220 Exam 3

In early development what do both sexes have the same of?

The same anatomy and same two sets of internal ducts

What do the testes produce

androgens and MIH

What gene in males cause the gonads to develop into testes

SRY gene

What do androgens do

Cause wolffian ducts to develop into male internal sex organs

What does MIH do

causes the mullerian ducts to degenerate

What occurs in the absence of androgens and MIH?

mullerian ducts develop into female internal sex organs and wolffian ducts degenerate

Most widely known estrogen

estradiol

Most widely known androgen

testosterone

Do testes have more androgens or estrogens

androgens

Do ovaries have more estrogens or androgens

estrogens

What do hormones do during the prenatal period?

differentiation of gonads, wolffian and mullerian ducts

differentiation of external genitals

What do hormones do during puberty?

secondary sex characteristics develop

What are hormones organizing effects associated with?

Long-lasting effects

associated with sensitive periods

What are hormones activating effects associated with?

temporary effects

can occur throughout lifetime

Examples of hormones activating effects

sex drive, arousal, menstrual cycle, pregnancy, parenting

Turner Syndrome (XO)

Gonads: absent or poorly developed ovaries

Internal sex organs: born with ovaries that fail to develop properly

External sex organs: female external organs

Fertility: not fertile

Secondary sex characteristics: puberty usually delayed or absent

Klinefelter Syndrome (XXY)

Gonads: testes (often smaller than typical)

Internal sex organs: typical male (seminal vesicles, vas deferens)

External sex organs: typical male (smaller penis)

Fertility: infertile

Secondary sex characteristics: some feminization (breast development, rounding of hips)

Androgen Insensitivity Syndrome (AIS)

chromosomally typical male

insensitive to androgens

gonads: testes (not dropped)

internal sex organs: no female internal organs

external sex organs: typically female

Fetally androgenized females

chromosomally typical female (XX)

exposed to high levels of androgens

ovaries and internal structures are typical female but external genitals are ambiguous/more typical male

DHT-deficient males

chromosomally typical male (XY)

testosterone does not convert to dihydrotestosterone

undescended testes, external genitals are ambiguous/more typical female

Characteristics of female brains

smaller overall size, more convolutions, and less white matter

stronger connections between the two hemispheres

Characteristics of male brains

larger overall size, fewer convolutions, and more white matter

more connections within each hemisphere

Sex differences in play

boys more often choose to play with toy cars and trains. balls, guns, and roughhouse activities

girls are more likely than boys to prefer calmer, more cooperative play

What do girls with CAH show

as a result of imbalances in androgens, girls exhibit increased male-typical toy and play preferences

girls with typical female sex development show a positive correlation between prenatal testosterone levels and male-typical toy preference/play

Effects of androgens (testosterone) during early development (gender identity: nature)

girls with CAH show increased male-typical toy/play preferences

males with androgen insensitivity often identify as girls/women

males with DHT deficiency often identify as girls pre-puberty

David Reimer

Chromosomal male

Penis was severely damaged during circumcision, parents chose to raise as girl; however, preferred boys’ toys/activities

Eventually reassumed male gender identity at age 14

Gender identity: nurture (influence of parenting)

Describe boys as strong and active; girls as soft and delicate

Encourage boys to be assertive and control their emotional expression; girls are encouraged to express emotions

Girls are typically assigned more household work

Gendered toye

Gender identity: nurture (influence of peers)

Voluntary separation between boys and girls

• preschoolers select members of the other sex as playmates as little as 10% of the time

Conformity and belonging in adolescence

Sexual orientation

Sexual, emotional, and/or romantic attraction one has to others

Usually labeled based on the sex/gender of the person to whom you are attracted, in relation to your own

What determines sexual orientation

No single causal theory that is widely accepted

Variability in how researchers group subjects into sexual orientation groups

Sexual orientation (genetics)

Twin concordance studies

Candidate genes have been identified but no single genetic cause

Some heritability (8-25%) but size and mechanism of effect is uncertain

Sexual orientation (prenatal variables)

Homosexuality is slightly more probably among men who have older biological brothers (maternal immunization hypothesis)

Prenatal stress

Maternal immunization hypothesis

Pregnancy #1: placental barrier protects mom and baby from exposure to the other’s proteins

Exposure: mixing of fluids during delivery exposes mother to male-specific protein, NLGN4Y

Antibodies: mother’s immune system produces antibodies to these proteins, Anti-NLGN4Y

Pregnancy #2: placenta transports antibodies, differentially affecting boys

Sexual orientation: prenatal variables (Prenatal stress)

Pregnant rats exposed to stress during the final week of pregnancy

• Female pups displayed sex-typical behavior

• Male pups displayed female-typical sex posture in the presence of other males

• Endorphins antagonize the effect of testosterone of the hypothalamus

• Adrenal hormones (cortisol) decrease testosterone release

Classical conditioning

conditioned stimulus with unconditioned stimulus produces unconditioned response and eventually conditioned response

Applications of classical conditioning

Fears and phobias can be learned via classical conditioning

How to reduce the conditioned response or fear response

counterconditioning where you pair the fear producing conditioned sitimulus with a positive unconditioned stimulus

graduated exposure, where you pair relaxation with a hierarchy of fear producing stimuli

Pavlov’s Theory

Before conditioning, the US excited the UR (reflexive, automatic response)

After conditioning, the CS excited the US center which in turn, elicits the UR

Lashley’s engram

The connection between two brain areas; a physical representation of learning

No cut or combination of cuts across the cortex interfered with a rats memory of a maze

Why did Lashley’s search for the engram fail?

he wrongly assumed memories were localized in specific cortical areas when in reality memories are distributed across the brain and stored in subcortical structures he didn’t examine. memory depends on total amount of brain tissue and is a distributed network of neurons.

Modern search for the engram (why were later attempts successful?)

researchers began to look in the correct areas?

What is sensory memory?

large capacity, brief retention (0.5-2 seconds)

What is short-term memory?

limited capcity, limited retention

What is working memory?

updated conceptualization of working memory

storage of information while we are working with it

What is long-term memory?

unlimited capcity, retention for extended periods of time (e.g. years)

What are the two types of long-term memory

explicit and implicit memories

What is explicit/declarative memory

deliberate recall of information; “knowing what”

Two types: semantic and episodic memory

What is semantic memory?

factual information

What is episodic memory?

Personal experiences that occurred at a particular time and place

What is the relationship bewteen hippocampus and explicit memory?

Hippocampal damage strongly impairs performance

rat with hippocampal damage can find the platform if he always starts from the same place, but he will be disoriented if he starts from a different location

What is implicit memory?

The influence of experience on behavior; “knowing how”

Two types: priming and procedural memory

What is priming?

enhanced ability to think of a stimulus as a result of recent experience/exposure

What is procedural memory?

development of motor skills and habits

What is the relationship between the striatum and implicit memory?

habits and skills develop slowly, and depend on the striatum

when the striatum is damaged, we don’t see gradual improvement on implicit memory tasks

Alzheimer’s disease characteristics

one of the most common causes of memory loss

symptoms include declarative memory problems, confusion, depression, delusions

marked by progressive atrophy

What are the causes of alzheimer’s disease?

Genetics

amyloid-beta protein

Tau protein

Alzheimer’s Disease Genetics

chromosome 21, APOE4 gene

Alzheimer’s Disease Amyloid-Beta Protein

damages cells, creates plaques

Alzheimer’s Disease Tau Protein

responsible for tangles, structures formed from degeneration within neurons

Korsakoff’s Syndrome

associated with severe alcoholism

thiamine (vitamin B1) deficiency

loss of neurons, brain volume

marked by confabulation (“honest lying,” marked by honest misinterpretation of memory)

What is the left brain responsible for?

right visual field, sensory/motor control of right side of the body, language, the “interpreter”

What is the right brain responsible for?

left visual field, sensory/motor control of left side of the body, spatial relationships, emotional tone of communication

Broca’s area

damage to this area results in Broca’s aphasia

effortful speech; difficulty finding words

language comprehension is generally not impaired

Located in left frontal cortex

Wernicke’s Area

damage to this area results in Wernicke’s aphasia

Fluent speech marked by anomia

poor language comprehension

Located in left temporal cortex

Speech/Language Perception

influenced by visual information

McGurk Effect

What is the McGurk Effect?

the audio stimulus is /ba-ba/ but when lip movements correspond to /fa-fa/, that is teh speech sound that we perceive

Speech segmentation

the acoustic signal for spoken sentences is continuous, but we can easily perceive individual words

Tritone Paradox

tones contain both high and low frequencies; perception depends on experience

Effect of experience on infants

at birth, infants can distinguish among all phonemes

• by 6 months, we lose the ability to distinguish among phonemes that are not present in the speech we hear

• ex) japanese infants older than 6 months do not distinguish between /la/ and /ra/

When is the sensitive period for language development?

children have an advantage in mastering grammar and pronounciation of a second language

a child who learns no language while young may have permanent impairment or difficulties if attempts are made to learn language at a later time

Substance Use Disorder

continued consumption despite negative impact on work, family, health

risky/dangerous use of one or more substances

Agonist

mimics the effects of a neurotransmitter

antagonist

blocks a neurotransmitter

Role of Dopamine

stimulants: increase/prolong the release of dopamine in the nucleus accumbens

important for “wanting”

most people who become addicted to a substance do not enjoy the experience, they want it

Cravings

insistent search for the substance

in drug addiction, over time, less dopamine is released in response to the substance

cues associated with the drug are associated with increased dopamine activity

nucleus accumbens becomes less responsive to other types of motivation

Substance Use Genetics

parents’ alcohol use correlates with that of their biological children

genes that control the metabolism of alcohol

• alcohol dehydrogenase (ADH) family (e.g., ADH1B) —> metabolizes acetaldehyde to acetate

Substance Use Treatment

alcoholics anonymous, narcotics anonymous, etc.

cognitive-behavioral therapy

antabuse

• antagonizes aldehyde dehydrogenase

• learned aversion (induces severe discomfort)

methadone

Major Depressive Disorder Symptoms

at least one of the following:

• depressed mood most of the day, nearly every day

• markedly diminished interest/pleasure in all, or almost all, activities most of the day, nearly every day

plus, 3 to 4 of the following:

• significant weight loss/gain, or change in appetite

• insomnia or hypersomnia nearly every day

• increase or decrease in psychomotor activity

• fatigue or loss of energy nearly every day

• feelings of worthlessness nearly every day

• diminished ability to concentrate/indecisiveness

• suicidal ideation, plans, or attempt

Major Depressive Disorder Brain Regions

cortical areas (prefrontal cortex, anterior cingulate cortex, insula)

subcortical limbic areas (amygdala, hippocampus, thalamus)

basal ganglia and brainstem

reduced connectivity in these regions

Major Depressive Disorder Sleep Patterns

circadian rhythms are often shifted

fall asleep at a “normal” time but awaken early and have difficulty falling back to sleep

also enter REM sooner than normal

Seasonal Affective Disorder

form of depression that regularly occurs during winter

more prominent closer to the poles, where amount of daylight is most impacted

Major Depressive Disorder Genetics

moderate degree of heritability

• at least 17 common genetic variants

two types of the serotonin reuptake gene: long (l) and short (s)

short form magnifies reactions to stressful events, which in turn contributes to the development of depression

Major Depressive Disorder “Nurture”

clear genetic contribution, but environmental events are often the immediate triggers (e.g., pain, stress)

Major Depressive Disorder Treatment

antidepressants: tricyclics, selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs)

Cognitive behavioral therapy

electroconvulsive therapy (ECT)

What do tricylics do?

block reuptake of serotonin, dopamine, and norepinephrine

prolonged presence of the neurotransmitter in the synapse

side effects: drowsiness, dry mouth, heart irregularities

Selective serotonin reuptake inhibitors (SSRIs)

block reuptake of serotonin

side effects: nausea, headache, dizziness, dry mouth, restlessness

Serotonin norepinephrine reuptake inhibitors (SNRIs)

block reuptake of serotonin and norepinephrine

side effects: nausea, vomiting, dizziness, dry mouth, drowsiness

Monoamine oxidase inhibitors (MAOIs)

block monoamine oxidase, a presynaptic enzyme which metabolizes serotonin into an inactive form

results in more serotonin available for release

requires dietary restrictions

Antidepressants Effectiveness

moderately effective as compared to placebo

effect seems to be stronger for more severe depression

trial and error is often required

Cognitive behavioral therapy

learn to change thoughts and behaviors that contribute to depression

effects are about equal to that of antidepressants, are more long-lasting and there aren’t side effects

but requires more time from patient and isn’t always covered well by insurance

Electroconvulsive therapy (ECT)

electrically induced seizure

• used for severe depression and/or depression that has not responded to other treatments

• side effects: memory impairment

Schizophrenia symptoms

hallucinations; delusions; disorganized thoughts and speech; changes in behavior; abnormal patterns of movement

lack of emotion; social withdrawal; struggling with personal care; lack of motivation, ambition and commitment

Schizophrenia Anatomy

decreased brain volume (both gray and white matter), larger than average ventricles, smaller hippocampus, impaired functioning of the prefrontal cortex

Schizophrenia Role of Dopamine

dopamine release is increased in the basal ganglia

excess activity at dopamine synapses

note) there are dopamine receptors throughout the brain, at any given time some are occupied while others are not

IBZM measures dopamine activity

IBZM

radioactively labeled drug, binds to dopamine receptors that are not already occupied, amount of radioactivity measured reflects the volume of unoccupied D2 receptors

AMPT

blocks the synthesis of dopamine causing all D2 receptors to be vacant and then IBZM now binds to all D2 receptors

Number of D2 receptors occupied by schizophrenic patients and how to measure

usually have twice as many D2 receptors occupied

subtract total number of receptors measured using AMPT and then IBZM, by number of unoccupied receptors measured using just IBZM

Schizophrenia Genetics

highly heritable

monozygotic twins = 48%

dizygotic twins = 17%

siblings = 9%

Schizophrenia Prenatal Factors

poor prenatal nutrition, premature birth, low birth weight, and complications during delivery elevate the risk for schizophrenia

maternal stress and prolonged illness during pregnancy is also a risk factor

maternal Rh-negative blood type

• increased risk of schizophrenia for Rh-positive baby

• risk increases for subsequent Rh-positive babies

Schizophrenia Childhood Risk Factors

trauma (e.g., physical, emotional, sexual abuse)

head injuries

exposure to toxoplasma gondii