psych paper 2 - biopsychology

localisation of function (phineas gage)

Phineas Gage - iron bar went through skull and experienced a change in personality eg anger and loss of inhibitions

this provides evidence to support localisation of function as it was believed the area the iron bar hit (amygdala) was responsible for personality and aggression

lateralisation

brain divided into left hemisphere and right hemisphere

the left side of your body is controlled by your right hemisphere and right side controlled by left hemisphere

cerebral cortex divided into 4 lobes:

frontal lobe

temporal lobe

parietal lobe

occipital lobe

localisation of function (brocas area)

brocas area: reposible for speech production in left frontal lobe, damage to this area causes brocas apahsia causing slow speech that lacks in fluency

brocas patients had trouble finding words and naming objects

pateints with brocas aphasia have difficulty with prepositions and conjunctions eg tan

tan could only use the word tan

localisation of function (wernikes area)

responsible for language comprehension identified in the back of the temporal lobe

patients produce language but have problems understanding it they produce fluent but meaningless speech

patients with wernikes aphasia often produce nonsense words

motor cortex

motor area is located towards the back of the frontal lobe and is responsible for voluntary movements by sending signals to muscles

synaptic transmission

action potential reaches axon terminal

calcium channel opens

calcium causes vesicles to release a neurotransmitter

neurotransmitter crosses synapse

neurotransmitter binds to neuroreceptors

triggers signal in post synaptic neuron

fight/flight response

amygdala senses danger

alerts hypothalamus activating pituitary gland

sympathetic branch activated stimulating adrenal medulla

parasympathetic activated after threat has passed

ao3- females more categorised by a pattern and befriend rather than fight or flight they protect themselves

gender bias- research only conducted on males so may misrepresent female behaviours

hemispheric lateralisation

each hemisphere of the brain has specific functions

the corpus callosum connects the two hemispheres of the brain allowing you to use both sides together

sperrys split brain research- quasi experiment on split brain patients- showed patients can verbalise an image shown to their right visual field and their left visual field and can draw it with their left hand

if shown an image in both visual fields they will say what they have seen in their right visual field but draw the image

ao3- controlled method with standardised procedures, procedures can be replicated

lateralisation changes with age

biological determinism - makes medical interference easier as you don’t have a choice what your brain does

plasticity

the brains ability to adapt as a result of experience

as we age rarely used connections are deleted and frequently used are strengthened

study conducted where playing video games for 30 mins per day for 2 months increased grey matter in areas of the brain resulting in better motor performance

prolonged drug use leads to worse cognitive functioning

ao3- animal studies with rats showed environmental and life experience positively influences plasticity in the brain

reductionist theory

circadian rhythms

biological rhymth that takes 24 hours

endogenous pacemakers- internal body cues regulating biological rhythms eg hormones

exogenous zeitgabers- external cues that reset our internal body clocks through entrainment eg light dark

Micheal siffre - spent 2 months in a cave with no exogenous zeitgabers

ao3- sleep wake cycles vary from person to person

determinism- idea it is controlled by sin is deterministic as it assumes we have no choice over sleeping patterns

biological rhythms

ultradian rhythms take less than a day

sleep stages- 5 sleep stages

basic reset activity cycle - 90 min cycle that continues through daytime alter for 90 mins then fatigued

infaradian rhythms - takes more than 24 hours

human menstrual cycle

ao3- mclintok - longitudinal study involving 29 women with irregular ovulation, samples of pheromones taken and wiped under noses daily 68% responded to pheromones