PSYC 207 Final

microbirth highlights

microbirth highlights

• we are losing diversity in microbes → leads to increased disease

• during C sections, infants won’t get essential bacteria thru the vaginal canal and have health problems

associative memory

• your implicit model of the world

• based on context clues

  • eg: something you do a lot = statistical regularity

semantic memory

• explicit model of the world

• general knowledge (facts, ideas, concepts)

  • culture = major source

    • what we are exposed to every day

    • repeated exposure strengthens some associations

    • lack of exposure weakens other associations

what determines your internal reaction?

intuitive valuation + deliberate evaluation of the situation

• this comes from associative and semantic memory

conditioning

a major way of learning new associations, thus forming more associative memories

mass media affects associative memory how?

associated with danger and speed

alternative media affects memory how?

safety and slowness

system 1

• automatic process that generates impressions

• fast, effortless, emotional

  • these are called intuitive valuations

  • inferences of what can happen → alternatives to that narrative

system 2

controlled process (mostly conscious)

• searches examples of whether system 1 is right or not

• flexible, memory retrieval, slow, controlled

how system 1 and 2 interact

• associate memory → intuitive judgements

  • if rejected, goes in favour of deliberate judgements

  • if accepted, considered as similar enough to deliberate judgements

availability heuristic

• when examples of something come to mind easily

• if there are many examples, this means it must occur frequently

  • system 2 judges whether frequency is high

• special type of fluency heuristic

  • processing fluency: how easy it is to process information

dual system model errors

• errors in judgement can occur when:

  • system 1’s intuition is faulty

  • system 2 does not realize to correct it

judgement

weighted combination of pieces of information

judgement bias

over/underestimating relevance of certain information

heuristics vs statistics

• heuristics: subjective probabilities

• statistics: objective probabilities

probabilistic view of danger

• measured in micromorts (1/million deaths)

• variability of danger based on country

• culture-based perceived control influences how dangerously we view something

• solutions:

  • words of estimating probability (this adjective = this %)

  • take away weasel words, which are vague and can be misleading

robust bias

judging something without considering other factors that affect the subject

probabilistic danger of birth

• belief there is less control over birth

• actually, being born is less safe than giving birth

• cultural perspectives on birth avoid:

  • physiological reality

  • emotionality

motivation of reasoning

• accuracy motive

  • the motive to be accurate

• directional motivation

  • motivation to arrive at a directional explanation

• these are biased, used to justify a conclusion

membrane sweeping

• gloved fingers into vagina, sweeping around cervix and membrane to dislodge baby’s head

  • this prepares for birth

• why? helps release endogenous prostaglandins

prostaglandins

hormone-like lipid compounts that help initiate labour

pros of membrane sweeping

• may reduce rate of formal medical induction (1/8, but 7/8 nothing happens)

• may decrease length of pregnancy by 1-4 days

cons of membrane sweeping

• very painful

• can cause bleeding/irregular contractions

• in 1/10 women, leads to water breaking (rupture of amniotic sac)

  • this leads to formal induction within 24 hours anyways → the point of membrane sweeping is to hopefully avoid formal induction

methods of formal induction: artifical oxytocin (pitocin, IV drip)

• currently recommended, most common

• continuous administration of oxytocin through labour and after delivery

methods of formal induction: prostaglandins/vaginal misoprostol

• more effective than oxytocin to induce vaginal delivery in 24h (+)

• more likely than oxytocin to cause uterine hyperstimulation (-)

  • if contractions are too strong, they can cut off oxygen and nutrients from the baby

• increased chance of infection from fingers applying (-)

methods of formal induction: mechanical methods

eg: balloon catheters, amniotomy (mechanical = not as common)

• balloon catheter: physically dilates cervix

• amniotomy: artificial breaking of amniotic sac

• less uterine hyperstimulation than prostaglandins (+)

• increased maternal/neonatal infections compared to prostaglandins/artificial oxytocin (-)

risks of inductions

• offered at 41-42 weeks

• due to small decrease in perinatal mortality (when induced)

• later in pregnancy (past 40 weeks) = higher risk of still birth

  • small increase

• 500 inductions are performed to prevent one stillbirth

precautionary principle

assumed unsafe until proven otherwise

anticautionary princple

assumed safe until proven otherwise

• common in obstetrics and medicine in general

medical reversals

• research on medical practices about pregnancy can see sudden changes because they are not based on well-tested trials

• a problem might only be discovered after many people have already gone through it

early cord clamping

• does not decrease postpartum hemorrhage rates like intended

• can lead to iron deficiency/anemia in babies

• for premature infants, can lead to intraventricular hemorrhage (brain bleeding)

delayed cord clamping

• thought to increase chances of jaundice (not actually true)

• increases need for phototherapy (-)

medical knowledge

• mostly procedural (active/procedure)

• some semantic (factual)

  • semantic explains reasoning behind procedural knowledge

  • eg: why certain practices are adopted, while others aren’t

scientific knowledge

• mostly semantic

• some procedural

  • procedural knowledge serves semantic knowledge

  • eg: prescribes what we should do to update/improve semantic knowledge

evidence-practice gap

• it takes many years for few new scientific discoveries to enter real-life clinical practice

• clinical articles usually examine new practices than the flaws in standard care that already exists

Cochrane

• advocated for use of randomzied control trials

• created Cochrane Library database

• start of evidence-based medicine

informed consent

• straightforward/black and white thinking

• clinical based on benefit vs harm

• risks and benefit = subjective

• doctors usually offer instead of recommend

  • may coerce if otherwise puts fetus at risk

• informed consent means women have full choice

semantic knowledge

facts about the world, eg: learned from a textbook

• changes based on the evidence we are exposed to

• ‘evidence’ can be faulty

procedural knowledge

• learned from doing something

• changes based on:

  • habits

  • reward/punishments in the environment

duty of care

obligation to adhere to standards set by the regulating college

amygdala

• detects emotionally salient things

  • eg: positive experiences,

• stronger emotional salience = more active amygdala

• carries information quickly but not specific

emotional salience

emotional significance of perceptions, thoughts, etc.

• can draw/sustain attention through mechanisms outside of cognitive control

cognitive control

deliberate guidance of current thoughts, perceptions or actions

• control is imposed in a goal-directed manner with active top-down executive processes

ventromedial prefrontal cortex (VMPFC)

• receives info of what’s happening in other areas of the body

  • help us understand emotionally salient things

• summarize multiple salient things to create a “gut feeling”

  • this influences our conscious state

• this is how emotional processes can guide/bias reasoning

when incongruent with our dominant values

• this is cognitively difficult to understand

• must recruit cognitive control with the lateral PFC

when congruent with our dominant values

• recruit the VMPFC

• high processing fluency

Georgia case

• placenta previa: placenta blocks birth canal opening

  • drs wanted her to have a C section, but she did not want to for religious reasons

  • baby would die (99%) and mother (50%) without C section

  • court chose C section against parents

• 2nd ultrasound → placenta ‘moved’, no C section necessary

• what actually happened:

  • placenta previa was missed clinically and by ultrasound at 35 weeks

  • after vaginal delivery, a hole in the middle of the placenta was found → the fetus was delivered through this

ultrasound (sonography)

• uses sound waves (we cannot hear)

• sends pulses of ultrasound into tissue using probe

• when sound wave encounters material with different density, part is reflected back and detected as an echo

  • greater difference in destiny = greater echo

• seeing deep into the body with ultrasound = difficult

  • most of signal is lost from acoustic absorption

• false positives/misses can be produced

Pennsylvania case

• at the first hospital, mother was told her baby was too big to deliver vaginally, needed a C section

  • had already given birth to 6 babies vaginally (each 12 lbs)

• went against dr’s advice and went to a second hospital

  • first hospital’s lawyers went to court → allowed to force mother into surgery if she returned

• at the second hospital, she had an easy natural birth

electronic fetal monitoring (EFM)

• meant to reduce, but did not actually improve:

  • cerebral palsy

  • mental retardation

  • perinatal mortality

• interpretations are highly subjective

• little agreement of ‘non-reassuring’ tracings

• false positive predictions of fetal distress (99%)

• increased rate of C sections but not actually improving outcomes for babies

• used to see when brain injuries occurred in legal debate

counterfactual reasoning

• reasoning about “what might have been”

• mental representations of past alternatives, activated automatically in response to a negative affect

• “if, then” statements

hindsight bias

• “knew it all along”

• knowing an event occurred increases its perceived predictability

• overconfidence in judgement

• linked to availability heuristic

labour pain in mass media

• self-evident, indisputable

• unavoidable except through pain medication

• so bad, you want to die

• makes women go mad and become violent

why do pregnant women watch shows based on pregnancy?

it helps them understand what it would be like to give birth

alternative media portrayal of labour pain

• one of the many sensations of labour

• bliss, joy, satisfaction, excitement are more powerful than the pain

perspectives on birth depend on…

• female vs not

• present during natural childbirths or not

information

sensory data we obtain with context and meaning

• eg: stories, images, sensations, feelings

knowledge

inferences we draw from theories we construct from our interpretations of the info we have

• to enable action

when new information does not change our knowledge

• credibility is low → info is discarded

• credibility is acceptable but clashes with pre-existing knowledge → considered an exception

alternative media is not a source of new knowledge because…

• information clashes with our pre-existing knowledge

• even if credible, we don’t know what to do with this new info

what are labour contractions

• strong muscle uterine contractions

different types of muscle fibres

• skeletal

• smooth

  • myometrium consists of smooth muscle

• cardiac

skeletal muscle

attached to bones to help us move around

smooth muscle

found in most internal organs, eg: digestive system, bladder, blood vessel

can women voluntarily stimulate contractions?

no, because smooth muscle cannot be voluntarily controlled

when does the non-pregnant uterus contract?

• all the time (spontaneously)

• during menstruation

• during orgasm

uterine quiescence

no spontaneous contractions

when does the pregnant uterus contract?

• uterine quiescence until late pregnancy (37-40 weeks)

• spontaneous ongoing contractions (Braxton-hicks) for practice

• orgasms

• labour/birth

• postpartum (to shrink back to original size)

pregnancy-induced hypoalgesia

almost complete denervation of uterus at term/37-40 weeks

why is there uterine quiescence?

otherwise, contractions would hurt baby/cause premature birth/spontaneous abortion

why does labour hurt?

no answer, a scientific mystery

hypoalgesia

decreased sensation of pain

what division of the nervous system controls muscles directly?

the PNS

PNS divisions

• motor (efferent)

  • motor innervation of all skeletal muscles

• autonomic

  • motor innervation of smooth muscle, cardiac muscle, glands

innervation density decreases in pregnancy

• due to ovarian hormones

• hypertrophy of uterine myocytes

• decrease in number of nerve fibres

motor denervation

• done by ovarian hormones

• helps maintain uterine quiescnece

• is not absolute (eg: abortion can be induced)

• maintains uterine tone, but resistance to contractions

• contractility control is based off hormones

myometrium vs endometrium

myometrium:

• innervated through autonomic nerve fibres

• denervated during pregnancy

endometrium

• uterine lining

• glands/tiny blood vessels

• releases hormones

sensory denervation in pregnant uterus is..

• not very well understood

• possibly reduces contractility

  • because stretch sensations may induce contractions

• only in uterine muscle

common explanations for why labour contractions hurt?

• stretching of the cervix

• contraction of uterine muscle

according to scientific evidence…

• stretch receptors in uterus disappear during pregnancy

• stretch receptors in cervix disappear at beginning of labour

• muscle fibres in cervix are almost fully replaced by connective tissue

  • so why does labour hurt?

stage 1

uterus contracts/stretches the cervix to open 10cm diameter

stage 2

baby passes through birth canal and is born

stage 3

placenta is born/expelled

postpartum stage

uterine contracts to return to original shape

in general, pain in labour…

• is felt only during contractions

  • no pain in between contractions

• strongest sensations inside the body

during ‘back labour’

• pain may still be felt between contractions

• strongest sensations are at the lower back

4 explanations to why labour hurts

• release of chemicals from muscle exertion

• vasoconstriction of uterine blood vessels

• inflammation

• reduced O2 delivery to tissues/ischemia

why does physical exertion hurt?

• injecting muscle metabolites → sensations of muscle fatigue, pain

• physiological concentrations of metabolite combinations

  • H+, lactate, ATP

why does vasoconstriction of uterine blood vessels hurt?

• uterus must contract to give birth

• contractions reduce blood flow to uterus/baby

• contraction myometrium compresses the blood vessels

  • stronger/longer contraction = more blood flow reduced

  • some hypoxia during every contraction

• innervation of blood vessels/endometrium stay during pregnancy and childbirth

pain during labour is a way to..

prevent injury of the mom and baby

benefits to normal labour pain

• guides the birthing woman through process

• focuses mental and physical resources on the birthing process

• regulate strength of contractions

  • prevents injury to mom and baby

• pain leads to the release of

  • stress hormones/neurotransmitters

  • endogenous opioids

pain can suppress the release of which hormone?

oxytocin → reduce the strength/duration of contractions during stage 1 to protect mom/baby

nociception

encoding/processing of harmful stimuli in the nervous system, so the body can sense potential harm

nociception vs pain

nociception: sensory process that produces nerve signals to trigger pain

pain: a subjective experience

context of pain

• our own mind, and the conceptual framework we interpret our experience

• the people around us, with their on conceptual frameworks that determine what people say to us/how they view us

divisions of nociceptive input

visceral vs non-visceral/somatic

visceral input

• from internal organs, eg:

  • stomach

  • bladder

  • blood vessels

• carried by C fibres

non-visceral/somatic input

from body parts that are not internal organs

• bones

• skeletal muscles

• skin, etc.

C fibres vs A-delta fibres

• both carry noxious sensory input

• C: carry slow pain, evolutionarily old

• A delta: carry fast pain, evolutionarily new

proprioception

the sense of where one’s own body is in space (relative to other objects)

• signals from joints, tendons, muscles