biopsychology A03 Flashcards
Fight or flight
reductionist
- Ev - freeze effect - avoiding confrontation, hypervigilant to threat, decide best course of action
- Ex - humans have cognition to problem solve, not just instinctive bio response to threat
- L - But ‘freeze’ still evolutionary survival instinct - playing dead to ensure survival.
_gender differences__
- Ev - Taylor et al -
Women = ‘tend and befriend’
Men = FoF.
women more likely to protect offspring and form alliances with other women.
- Ex - Oestrogen enhances the effects of oxytocin (‘love hormone’), increasing nurturing beh’s.
testosterone inhibits it, and linked to aggression (fight).
- L - Some males tend and befriend - seek out others when stressed for social support. Gender biased to assume aggression from FoF only male- alpha bias.
outdated explanation
- Ev - Modern times - stressors = chronic + long lasting (e.g. lack of money, job stress) rather than short term with ancestors.
- Ex - FoF adapted for survival. Modern stressors can’t be solved through this basic bio system. Ignores role of cognition to deal with modern stress.
- L - do still use FoF but isn’t maladaptive - can create health problems (stroke, heart attack). So if FoF evolutionary, should devolve over time.
localisation of function in the brain
research support from case study
-Ev - Tan - could only say ‘tan, tan’ - lesion in Broca’s area. could do other functions such as maths
-Ex - Therefore Broca’s area is localised in its function for speech production. He had language comprehension and mathematical ability, so brain lobes have specific functions.
-L - but unique case study, can’t see function whilst alive - only after in post mortem.
correlational - may not be precise damage to Broca’s - modern fMRI scans shows other areas involved in speech production, so maybe not as localised as thought.
gender differences
-Ev - women have a larger Broca’s and Wernicke’s area than men
- Ex - not all individuals brains are localised in the same way - not innate, created by env.
Brian becomes more localised due to plasticity - primary socialisation (girls = language dev, boys = active playing - spatial areas)
-L - doesn’t criticise theory - specialised areas of brain are responsible for certain functions, but specialism = adaptive to a persons environment/ nurture.
brain only localised for simplistic functions
-Ev- higher mental functions, e.g. decision making and problem solving aren’t localised. Simpler functions such as language are more localised.
-Ex - this suggests brain isn’t intended to be localised and all parts of brain are used equally for a function.
more important to consider how diff areas work together rather than sep
-L - summary: useful in understanding basic localised functions of brain.
but unless we fully understand how areas communicate, we can’t understand complex mental processes e.g. memory, perception, attention.
This can be done through use of new technology (fMRI scans)
lateralisation
highly scientific research support
-Ev - lots of controls, e.g. 1/10th sec, hands in box, blindfolded in one eye, control group
- Ex - strong causation, could only be due to the hemisphere that causes the issue with the object/ face rec/ language.
-L - but sample has individual differences, e.g. in severity of epilepsy prior to surgery. Also the epilepsy could have changed the localisation of functions of their brain, therefore it doesn’t account for plasticity and isn’t generalisable.
further research support for lateralisation
- Ev - Roger’s et al: chickens - brain lateralisation associated with enhanced ability to perform two tasks simultaneously: finding food and being vigilant for predators.
- Ex - Proves lateralisation is evolutionary and necessary for survival and that all mammals have this function.
-L - however, humans aren’t prey but predators and hence de-lateralisation is more advantageous- need to be able to use all of our brains for complex functions.
lateralisation changes with age
-Ev - over age of 25, brain becomes more de-lateralised.
-Ex - due to more life experience and plasticity both hemispheres of the brain take on the functions.
It’s simplistic to assume each hemisphere only does one function, more complex functions, e.g. problem solving needs both hemispheres to function together, not independently.
- L - but brain begins lateralised and not certain if de-lateralisation is negative due to decay with age or if the brain has improved by it.
plasticity
Criticism of Maguire’s Taxi Drivers research support
-Ev - sample bias (androcentric) and no before and after the knowledge test.
-Ex - can’t be certain if plasticity is same in women, or if ‘the knowledge test’ cause structural plasticity, or if they passed the test as their posterior hipp was already larger, hence better at remembering maps.
But, Maguire did further research to overcome criticism
-Ev - Same study but compared hipp before and after knowledge test.
Result: Posterior hipp did increase.
-Ex - learning mental map of london structurally and functionally changed their brains.
so brains do have plasticity and continue to develop as we learn.
but individual differences in level of plasticity ppl have
- Ev - gender - women have more plasticity in Broca’s + Wenicke’s area than men.
Education- undergraduate students that suffered brain damage had more plasticity than those without any qualifications (recovered more function)
Age - over 40 years plasticity decreases. takes longer to recover from brain damage.
-Ex - so, plasticity dependant on age, gender and education, suggesting it’s both env. and bio.
circadian rhythms (EP + EZ)
research to support role of EP’s in circadian rhythms
-Ev - 30 chipmunks had SCN removed and observed for 80 days. All chipmunks sleep-wake cycle ceased.
By end of study, significant proportion had been killed by weasels.
-Ev - The EP is responsible for keeping time to our circadian rhythm and ensures our survival.
-L - But humans are apex predators unlike chipmunks. EZ may be more important in humans, as less EP less needed for survival as we pray on other animals. E.g. Light from mobile phones interrupts the circadian rhythm of adolescents, affecting academic performance.
research to show EP important in human circadian rhythms
-Ev - Michael Siffre in cave for 2 months. No EZ - no light, clock, communication to outside world. Only could call out to his team. Found his circadian rhythm stayed at around 24.5hrs.
- Ex - EP (SCN) can hold humans to a 24hr circadian rhythm without any EZ. Therefore, our bio clock more
important.
- L- But case study of caver who was used to being underground. Was cold and wet, reducing his body temp, increasing sleepiness. So cannot
assume circadian rhythm is purely down to EP when living on the surface of earth.
real life application for role of EP
-Ev - Eskimos in arctic circle have daylight all summer and dark all winter. They maintained a 24hr circadian rhythm.
-Ex - Suggests humans don’t need an EZ (e.g. light) to regulate the circadian rhythm. EP = most important factor.
-L - But eskimos used blackout curtains during summer months and UV light during winter. Therefore stimulating the EZ to help maintain the circadian rhythm to 24hrs.
