biopsychology

Question 1

Structure + Function of Sensory, Relay + Motor Neurons: neurones (A01)

Answer 1

100 billion neurones in human nervous system 80% of which are located in brain- transmitting signals electrically + chemically these neurones provide nervous system w/primary means of communication

Neurones vary in size from less than millimetre to up to metre long depending on their function but all share same basic structure

Question 2

Structure + Function of Sensory, Relay + Motor Neurones: myelin sheath (A01)

Answer 2

If myelin sheath was continuous this would have reverse effect + slow down electrical impulse- myelin sheath is segmented by gaps called nodes of Ranvier

speeds up transmission of impulse by forcing it to ‘jump’ across gaps along axon

Question 3

Structure + Function of Sensory, Relay + Motor Neurones: synapse (A01)

Answer 3

end of axon are terminal buttons that communicate w/next neurone in chain across gap

Question 4

Structure + Function of Sensory, Relay + Motor Neurones: nucleus + dendrites (A01)

Answer 4

cell body includes nucleus which contains genetic material of cell Branch-like structures called dendrites protrude from cell body receive signals from other neurones or from sensory receptors

Question 5

Structure + Function of Sensory, Relay + Motor Neurones: axon (A01)

Answer 5

axon carries impulses away from cell body down length of neurone axon is covered in fatty layer of myelin sheath that protects axon + speeds up electrical transmission of impulse

Question 6

sensory neurons (unipolar) (A01)

Answer 6

found in receptors such as eyes ears, tongue + skin- carry nerve impulses from PNS to spinal cord + brain (CNS) these nerve impulses reach brain they are translated into ‘sensations’ such as vision, hearing, taste + touch

not all sensory neurones reach brain as some neurones stop at the spinal cord allowing for quick reflex actions- have long dendrites + short axons

Question 7

relay neurons (multipolar) (A01)

Answer 7

most common type of neurone

only found in brain + spinal cord (CNS)- connect sensory neurones to motor or other relay neurones

have short dendrites + short axons

Question 8

motor neurons (multipolar) (A01)

Answer 8

neurones carry messages from CNS + control muscle movements

stimulated these neurones release neurotransmitters that bind to receptors on muscle + triggers response which leads to muscle movement

Muscle relaxation is caused by inhibition of motor neurone
have short dendrites + long axons

Question 9

how neutrons function together (A01)

Answer 9

stimulus is presented

Sensory neurones send message through peripheral nervous system

message reaches spinal cord where it is passed to relay neurone
found throughout CNS

message is then either passed to motor neurone or sent to brain for further processing

motor neurone carries message to an effector such as muscle or gland motor neurone sends messages to muscles located in arm which contract - pulling hand away from candle

Question 10

synaptic transmission (A01)

Answer 10

Signals w/in neurones are transmitted electrically but signals between neurones are transmitted chemically across synapse

electrical impulse reaches end of the neurone it triggers release of neurotransmitters from tiny sacs -synaptic vesicles

Neurotransmitters are chemicals that diffuse across synapse to next neurone in chain

neurotransmitter crosses gap it is taken up by postsynaptic receptor site – dendrites of next neurone-chemical message is converted back to an electrical impulse + process of transmission begins again in this other neurone effects of this last until neurotransmitters travel back where they came from to be taken up again by presynaptic neurone-‘reuptake’ which allows neurotransmitters to be stored again + made available for later use

Question 11

neurotransmitters (A01)

Answer 11

Dozens of neurotransmitters have been identified in brain

Each neurotransmitter has its own specific molecular structure that fits perfectly into post-synaptic site like lock + key

Neurotransmitters also have specialist functions eg. dopamine affects nervous system in several ways including emotional arousal, pleasure + voluntary movement

Question 12

Summation (A01)

Answer 12

neurone can receive both excitatory + inhibitory neurotransmitters at same time

likelihood of cell firing is therefore determined by adding up excitatory + inhibitory synaptic input- summation if net effect on post-synaptic neurone is inhibitory neurone will be less likely to fire

if net effect is excitatory neurone will be more likely to fire

Question 13

Excitation + inhibition (A01)

Answer 13

Neurotransmitters have either an excitatory or inhibitory effect on neighbouring neurone

serotonin causes inhibition in receiving neurone resulting in neurone becoming more negatively charged + less likely to fire
message is likely to be stopped at post-synaptic neurone inhibitory synapse

dopamine causes excitation of post-synaptic neurone by increasing its positive charge + making it more likely to fire
synapse is more likely to cause post-synaptic neurone to fire- excitatory synapse

excitatory potential is like accelerator + an inhibitory potential is like brake

Question 14

central nervous system (CNS): brain (A01)

Answer 14

involved in psychological processes + is centre of all conscious awareness

brain’s outer layer cerebral cortex is highly developed in humans + is what distinguishes our higher mental functions from those of animals

brain is divided to 2 hemispheres

Question 15

central nervous system (CNS): spinal cord (A01)

Answer 15

extension of brain

responsible for reflex actions pulling your hand away from hot plate

responsible for relaying information between brain + rest of body

Question 16

peripheral nervous system (PNS) (A01)

Answer 16

PNS transmits messages via millions of neurones too + from CNS

nerves outside brain + spinal cord function of PNS is to relay nerve impulses from CNS to rest of body + from body back to CNS

Question 17

peripheral nervous system (PNS): Somatic nervous system (SNS) (A01)

Answer 17

controls voluntary actions

achieved by receiving info from senses + carrying sensory + motor info to + from CNS

Question 18

peripheral nervous system (PNS): Automatic nervous system (ANS) (A01)

Answer 18

governs vital functions in body such as breathing, heart rate, digestion, sexual arousal + stress responses

ANS controls involuntary actions eg. breathing, heart rate + digestion via internal organs + glands in body

ANS carries only motor info to + from CNS

Primarily involved in responses that help us deal w/emergencies

Neurones travel to virtually every organ + gland w/in body preparing body for rapid action

eg. sympathetic nervous system causes body to release stored energy pupils to dilate + hair to stand on end

slows down Inhibits less important bodily processes eg. digestion + urination

Question 19

endocrine system: glands (A01)

Answer 19

Organs in body that produce + secrete hormones to regulate many bodily functions

major endocrine gland is pituitary gland located in brain

called ‘master gland’ bc it controls release of hormones from all other endocrine glands in body

Question 20

Automatic nervous system (ANS): Parasympathetic nervous system (A01)

Answer 20

Primarily involved in returning to body to rest state once emergency has passed

sympathetic branch causes heart rate to become faster peripheral branch slows heartbeat down

bodily processes that are inhibited by sympathetic branch are returned to normal

Question 21

Automatic nervous system (ANS): sympathetic nervous system (A01)

Answer 21

involved in responses that prepare body for fight or flight
Impulses travel from SNS to organs in body to help us prepare for action when we are faced w/dangerous situation

Question 22

endocrine system (A01)

Answer 22

endocrine + nervous system work closely together to regulate various physiological processes in human body

endocrine system works much more slowly than nervous system but has widespread effect

endocrine communicates chemical messages to organs of body messages- hormones regulate body’s growth, metabolism + sexual development + function

Hormones are released from glands in body- major glands of endocrine system are pituitary, pineal, adrenals, reproductive organs + thyroid

pituitary gland- called master gland bc it controls several other hormone glands in your body including thyroid + adrenals, ovaries + testicles

Question 23

endocrine system: hormones (A01)

Answer 23

Chemicals that circulate in bloodstream + influence target organs in order to regulate bodily activity

produced in large amounts but disappear quickly- effects are very powerful

Question 24

glands adrenal: adrenaline FUNCTION (A01)

Answer 24

Triggers fight-or-flight response in stressful situation by increasing heart rate, dilating pupils

Question 25

glands testes: testosterone FUNCTION (A01)

Answer 25

development of testes in womb

surge of testosterone during puberty is also responsible for secondary sexual characteristics eg. facial hair + deepening voice

Question 26

glands ovaries: oestrogen +
progesterone FUNCTION (A01)

Answer 26

help to regulate menstrual cycle

Oestrogen is involved in repairing + thickening uterus lining whilst progesterone maintains uterine lining

Question 27

glands pineal: melatonin FUNCTION (A01)

Answer 27

Regulates sleep-wake cycle

High levels of melatonin cause drowsiness when daylight is low

Question 28

Fight or Flight Response Including Role of Adrenaline (A01)

Answer 28

experience an acute stressor hypothalamus directs sympathetic branch of ANS to send neurotransmitters to adrenal medulla

results in release of adrenaline to bloodstream- release of adrenaline as well as noradrenaline causes “fight or flight” response by triggering several physiological reactions

reactions include an activation of emergency functions such as increased heart rate + blood pressure so that oxygen is pumped to muscles to enable increased physical activity

Non-emergency bodily processes eg. digestion are suppressed here leading to ‘dry mouth’ + changes in stomach activity often associated w/these situations

Question 29

Fight or Flight Response Including Role of Adrenaline: sympathetic state (A01)

Answer 29

Increases heart rate
Increases breathing rate
Dilates pupils
Inhibits digestion
Inhibits saliva production
Contracts rectum

Question 30

Fight or Flight Response Including Role of Adrenaline: parasympathetic state (A01)

Answer 30

Decreases heart rate
Decreases breathing rate
Constricts pupils
Stimulates digestion
Stimulates saliva production
Relaxes rectum

Question 31

Fight or Flight Response: Adrenaline + Noradrenaline (A01)

Answer 31

Increase:
heart rate + blood pressure
glucose release
respiration + perspiration-sweat
blood coagulation

Decrease:
digestion

Question 32

Fight or Flight Response: may be different in females (A03) (1)

Answer 32

P: fight or flight response may be different in females

E +E: Taylor et al found that females adopt ‘tend + befriend’ response in stressful or dangerous situations Women are more likely to protect their offspring + form alliances with other women rather than fight an adversary or flee

L: suggests that research to fight or flight response is gender bias as biological processes that occur during stress may only apply to males

Question 33

Localisation of Function in Brain (A01)

Answer 33

specific functions have specific locations w/in brain

certain area of brain is damaged through illness or injury associated function will also be affected

brain is divided into 2 symmetrical halves called left + right hemispheres

outer layer of both these hemispheres is called cerebral cortex

Question 34

Localisation of Function in Brain: auditory centres (A01)

Answer 34

human brain has 2 primary auditory cortices 1 in each hemisphere

primary auditory cortex in both hemispheres receives info from both ears via 2 pathways that transmit information about what sound is + its location

located in temporal lobe either side of brain

Damage to this area may produce partial hearing loss more extensive damage more extensive loss

Question 35

Localisation of Function in Brain: motor centres (A01)

Answer 35

Movement is centred on motor cortex of brain which sends messages to muscles via brain stem + spinal cord

motor cortex is responsible for generating voluntary motor movements

located at back of frontal lobe in both hemispheres – motor cortex in each hemisphere controls movement in opposite side of body

Damage to this area may result in loss of control over fine movements

Question 36

Localisation of Function in Brain: somatosensory centres (A01)

Answer 36

referring to sensation of body
somatosensory cortex lies next to motor cortex in brain

somatosensory area is where sensory information from skin is represented

perceives touch so number of neuronal connections needed dictates amount of somatosensory cortex needed for that area of body

located at front of parietal lobe in both hemispheres

somatosensory cortex on 1 side of brain receives sensory information from opposite side of body

Question 37

Localisation of Function in Brain: visual centres (A01)

Answer 37

brain has 2 visual cortices 1 in each hemisphere

visual cortex is in occipital lobe which is at back of brain- main visual centre

located in occipital lobe at back of brain-each eye sends info from right visual field to left visual cortex + from left visual field to right visual cortex

means that damage to left hemisphere eg. can produce blindness in part of right visual field of both eyes

specifically an area called Area V1 which seems to be necessary for visual perception

individuals w/damage to that area report no vision of any kind

Question 38

Localisation of Function in Brain BROCA + WERNICKES AREAS: Language centres (A01)

Answer 38

left hemisphere + that is where most language processing in most of population is situated

Question 39

Localisation of Function in Brain BROCA AREAS: Language centres (A01)

Answer 39

identified area of brain responsible for speech production

located in small area in left frontal lobe

Damage to Broca’s area causes Broca’s aphasia which is characterised by speech that is slow, laborious + lacking in fluency

Question 40

Localisation of Function in Brain WERNICKES AREAS: Language centres (A01)

Answer 40

found that patients who had damage in an area close to auditory cortex had specific language impairments

included inability to comprehend language + anomia which is when someone struggles to find word they need

but Wernicke noticed that these people did have fluent speech when they could access words quickly

led Wernicke to suggest that area now called Wernicke’s area was important for understanding language + accessing words

Patients who have Wernicke’s aphasia will often produce nonsense words as part of content of their speech- small area in left temporal lobe

Question 41

Localisation of Function in Brain: Localisation supported by case study evidence (A03) (1)

Answer 41

P: Localisation supported by case study evidence

E: 1861 man who became known as “Tan” since this was only word he could speak met famous surgeon Paul Broca at hospital in France Shortly after meeting Tan died + Broca performed his autopsy During autopsy Broca found lesion in region of his brain

E: Broca concluded that Tan’s aphasia was caused by damage to this region + that this particular brain area-controlled speech- That region of brain was later renamed Broca’s area in honour of doctor

L: increases validity of theory of localisation as it appears damage to specific brain regions result in specific deficits

Question 42

Localisation of Function in Brain: supporting evidence from brain scan research (A03) (2)

Answer 42

P: supporting evidence from brain scan research

E + E: Peterson et al used brain scans to demonstrate how Wernicke’s area was active during listening task + Broca’s area was active during reading task Tulving et al have shown that episodic + semantic memories were recalled from different sides of prefrontal cortex whilst procedural memory is associated w/cerebellum

L: positive as there is wide range of evidence to support idea that different areas of brain have different functions

Question 43

Localisation of Function in Brain: evidence against localisation of function comes from animal research (A03) (3)

Answer 43

P: evidence against localisation of function comes from animal research

E: Lashley removed between 10-50% of cortex in rats that were learning maze + found that no area was more important than any other in terms of their ability to learn maze

E: problem as it suggests that higher cognitive processes eg. learning are not localised but distributed in more holistic way involving entire brain

L: reduces validity of theory of localisation

Question 44

Localisation of Function in Brain: Evidence from plasticity studies fails to support localisation of function (A03) (4)

Answer 44

P: Evidence from plasticity studies fails to support localisation of function

E + E: When brain has become damaged through illness or accident + particular function has been lost rest of brain is able to reorganise itself to recover function eg. Turk et al discovered patient who suffered damage to left hemisphere but developed capacity to speak in right hemisphere

L: suggests that functions are not localised 1 + brain can adapt following damage to certain areas

Question 45

Hemispheric lateralisation (A01)

Answer 45

idea that 2 halves of brain are functionally different + that certain mental processes + behaviours are mainly controlled by 1 hemisphere rather than other

human brain has 2 hemispheres which are bridged by corpus callosum-‘bridge’ which is bundle of fibres is communication pathway so that 2 hemispheres can exchange information

brain is contralateral in most people so parts of left hemisphere deal w/right side of body + right hemisphere does same for left side of body

Question 46

Hemispheric lateralisation: left hemisphere (A01)

Answer 46

language processing is done in left hemisphere

for many people if they have stroke on left side of their brain their speech is affected

bc Broca’s + Wernicke’s areas are found on left side of brain

Question 47

Hemispheric lateralisation: right hemisphere (A01)

Answer 47

dominant for facial recognition

case study of woman who had right hemisphere damage highlighted that right hemisphere also seems more adept at spatial relationships

woman would often get lost even in familiar situations

suggests that right hemisphere deals w/spatial information

Question 48

Hemispheric lateralisation: supporting evidence (A03) (1)

Answer 48

P: supporting evidence

E + E: Fink used PET scans to identify which brain regions were active during visual processing task when Ps were asked to attend to global elements of an image regions of right hemisphere were more active When required to focus in on finer detail specific areas of left hemisphere were more dominant

L: suggests tasks such as visual processing are feature of connected brain

Question 49

Hemispheric lateralisation: Evidence from plasticity studies fails to support lateralisation (A03) (2)

Answer 49

P: Evidence from plasticity studies fails to support lateralisation

E +E: When brain has become damaged through illness or accident + particular function has been lost rest of brain is able to reorganise itself to recover function eg. Turk et al discovered patient who suffered damage to left hemisphere but developed capacity to speak in right hemisphere

L: suggests that functions are not lateralised + brain can adapt following damage to certain areas

Question 50

Hemispheric lateralisation: contradictory evidence against lateralisation also comes from animal research (A03) (3)

Answer 50

P: Contradictory evidence against lateralisation also comes from animal research

E: Lashley removed between 10-50% of cortex in rats that were learning maze + found that no area was more important than any other in terms of their ability to learn maze

E: problem as it suggests that higher cognitive processes eg. learning are not lateralised but distributed in more holistic way involving entire brain

L: reduces validity of theory of lateralisation

Question 51

Hemispheric lateralisation: ‘lateralisation’ may be further complicated by age (A03) (4)

Answer 51

P: ‘lateralisation’ may be further complicated by age

E: means that research has shown lateralisation of function may change throughout an individual’s lifetime

E: eg. Szflarski who found that language became more lateralised to left hemisphere as children developed to adolescents but after age of 25 lateralisation decreased w/each decade of life

L: problem as it suggests hemispherical lateralisation is much more complex process than many realise w/many questions remaining as to why this happens

Question 52

split brain studies VERBAL RECOGNITION: procedure (A01)

Answer 52

visual image eg. picture of pencil was presented to left visual field via tachistoscope

Ps were asked to describe what they had seen- would then be repeated using right visual field

Question 53

split brain studies TOUCH RECOGNITION: procedure (A01)

Answer 53

patients’ hands were screened so they could not see objects in front of them

Ps would be asked to pick up an object using their right hand + then asked to describe what they had felt- would then be repeated using left hand

Question 54

split brain studies VERBAL RECOGNITION: findings (A01)

Answer 54

picture of an object was shown to patient’s right visual field patient could easily describe what was seen

but if same object was shown to left visual field patient could not describe what was seen + reported that there was nothing there

bc for most people language is processed in left hemisphere + therefore when picture was presented in left visual field this was processed by right hemisphere which has a lack of language centres to be able to describe it

allows us to infer that in normal brain messages from right hemisphere would have been relayed ‘across hemispheres’ to language centres in left hemisphere to describe it

Question 55

split brain studies TOUCH RECOGNITION: findings (A01)

Answer 55

patients could not verbally describe objects projected in their left visual field they were able to select matching object from grab-bag of different objects using their left hand

objects were placed behind screen so as not to be seen

left hand was also able to select an object that was most closely associated w/object presented to left visual field

each case patient was not able to verbally identify what they had seen but could nevertheless ‘understand’ what object was using right hemisphere + select corresponding object accordingly

Question 56

split brain research: support idea lateralisation is well controlled (A03) (1)

Answer 56

P: support idea lateralisation is well controlled

E: means methodology can be praised for using highly standardised procedures conducted in controlled environment to control possible extraneous variables

E: eg. images were flashed up for 1-tenth of second to ensure there was not time to spread info across both sides of visual field + subsequently both sides of brain

L: positive as it ensured research measured what it intended to give evidence high internal validity

Question 57

split brain research: evidence for lateralisation was flawed (A03) (2)

Answer 57

P: split-brain research evidence for lateralisation was flawed

E: means that findings came from very unusual + limited sample of people who were not well matched to control group eg. only 11 split-brain Ps took part in all variations of basic procedure all of whom had history of epileptic seizures + had received drug therapy for different amounts of time which may have caused unique changes in each of their brains

E: Some of Ps may also have experienced more disconnection of 2 hemispheres than others as part of their surgery-control group consisted of Ps w/no history of epilepsy making them poorly matched

L: problematic as it brings conclusions of research + support for lateralisation into doubt

Question 58

Methods of Studying Brain: functional magnetic resonance imaging (fMRI) (A01)

Answer 58

technique for detecting changes in blood oxygenation + flow in brain

brain area is more active it consumes more oxygen + to meet this increased demand blood flow is directed to the active area

FMRI produce 3-D images showing which part of brain is involved in particular mental process

eg. P might be asked to alternate between periods of doing task + relaxed state

resulting fMRI data can then be used to identify which areas of brain were being used when doing each task

fMRI images show activity approximately 1-4 seconds after an event occurs + are thought to be accurate w/in 1-2 mm

Question 59

fMRI: less invasive than other scanning techniques (A03) (1)

Answer 59

P: less invasive than other scanning techniques

E+ E: they don’t use radiation or require instruments to be inserted into brain

L: fMRI scans are virtually risk-free

Question 60

fMRI: good spatial resolution (A03) (2)

Answer 60

P: good spatial resolution of 1-2 mm

E + E: Spatial resolution refers to smallest measurement that scanner can detect- Greater spatial resolution allows psychologists to investigate brain regions w/greater accuracy

L: helps researcher’s pinpoint specific responses + exact source of brain activity

Question 61

fMRI: machines are expensive (A03) (3)

Answer 61

P: machines are expensive

E+ E: to buy + maintain + they require trained operators

L: makes research expensive + difficult to organise

Question 62

fMRI: Low temporal resolution (A03) (4)

Answer 62

P: Low temporal resolution

E+ E: refers to the accuracy of scanner in relation to time fMRI scans have temporal resolution of 1-4 seconds which is worse than other techniques eg. EEG/ERP which have temporal resolution of 1-10 milliseconds

L: Consequently psychologists are unable to predict w/high degree of accuracy onset of brain activity

Question 63

Methods of Studying Brain: electroencephalogram (EEG) (A01)

Answer 63

measure electrical activity w/in brain via electrodes that are fixed to an individual’s scalp using skull cap

scan recording represents brainwave patterns that are generated from action of millions of neurones providing an overall account of brain activity

can be anything from 2 to 3 electrodes to over hundred Electrodes measure activity of cells immediately under electrode so using more electrodes gives fuller picture

scan recording represents brainwave patterns that are generated from action of millions of neurones providing an overall account of brain activity

‘Real-time’ recording of brain activity

Question 64

Methods of Studying Brain: event-related potentials (ERPs) (A01)

Answer 64

issue w/EEG is that it only provides measure of general brain activity means that brain response to single stimulus or event of interest is not usually visible in EEG recording

possible to tease out + isolate specific sensory, cognitive + motor responses w/in EEG data

stimulus such as picture or sound is presented many times to P

Using statistical averaging technique, random or background brain activity from original EEG recording is filtered out leaving only event-related potentials

ERP is 1 of most widely used methods in cognitive neuroscience research to study physiological correlates of sensory, perceptual + cognitive activity associated w/ processing information

Question 65

EEG + ERP: less invasive than other scanning techniques (A03) (1)

Answer 65

P: less invasive than other scanning techniques

E+ E: they don’t use radiation or require instruments to be inserted into brain

L: EEG + ERP scans are virtually risk-free

Question 66

EEG + ERP: cheaper methods in comparison to fMRI scanning (A03) (2)

Answer 66

P: cheaper methods in comparison to fMRI scanning

E+ E: more widely available to researchers

L: Consequently this could help psychologists to gather further data on functioning human brain leading to greater understanding of sleeping + disorders eg. Alzheimer’s

Question 67

EEG + ERP: High temporal resolution (A03) (3)

Answer 67

P: High temporal resolution

E+ E: advantage of EEG/ERP technique is that it has good temporal resolution as it takes readings every millisecond meaning it can record brain activity in real time

L: leads to an accurate measurement of electrical activity when undertaking specific task

Question 68

EEG + ERP: poor spatial resolution (A03) (4)

Answer 68

P: poor spatial resolution

E+ E: EEGs/ERPs only detect activity in superficial regions of brain Consequently EEGS + ERPs are unable to provide info on what is happening in deeper regions of brain

L: making this technique limited in comparison to fMRI which has spatial resolution of 1-2 mm

Question 69

Post-mortem examinations (A01)

Answer 69

technique involves analysing person’s brain following their death

psychological research individuals whose brains are subject to post-mortem are likely to be those who have rare disorder + have experienced unusual deficits in mental processes or behaviour during their lifetime

Areas of damage w/in brain are examined after death as means of establishing likely cause of affliction person suffered

may also involve comparison w/ ‘normal’ brain to ascertain extent of difference

Question 70

Post-mortem examinations: ethical issues (A03) (2)

Answer 70

P: ethical issues in relation to informed consent + whether patient provides consent before his/her death

E+ E: many post-mortem examinations are carried out on patients w/severe psychological deficits who would be unable to provide fully informed consent + yet post-mortem examination has been conducted on his brain

L: raises severe ethical questions surrounding nature of such investigations

Question 71

Post-mortem examinations: provide detailed examination of structure of brain that is not possible w/other scanning techniques (A03) (1)

Answer 71

P: provide detailed examination of structure of brain that is not possible w/other scanning techniques

E+ E: Post-mortem examinations can access areas such as hypothalamus + hippocampus which other scanning techniques would struggle to reach

L: post-mortem examinations provide researchers w/insight into these deeper brain regions which often provide useful basis for further research

Question 72

Post-mortem examinations: issue of causation (A03) (3)

Answer 72

P: issue of causation

E+ E: deficit patient displays during their lifetime may not be linked to deficits found in brain- deficits reported could have been the result of another illness + therefore psychologists are unable to conclude that deficit is caused by damage found in brain

L: Other confounding factors include medication person may have been taking throughout their lives length of time between death + post mortem + age of person at death

Question 73

plasticity (A01)

Answer 73

brain’s capacity to change or adapt bc of new learning or brain trauma

well known that child’s brain changes during infancy as they acquire new knowledge + encounter new experiences but it is now known that this ability of brain does stop in childhood + that new neural connections can be made at any time of life

Question 74

functional recovery (A01)

Answer 74

Much recovery after trauma is due to anatomical compensation brought about by intensive rehabilitation

brain learns to compensate for lost functions

brain can be taught to learn how to use working faculties + function to compensate for ones that are lost forever

Question 75

functional recovery-brain after recovery: AXON SPROUTING (A01)

Answer 75

growth of new nerve endings which connect w/other undamaged nerve cells to form new neuronal pathways

When axon is damaged its connection w/neighbouring neurone is lost

some cases other axons that already connect w/that neurone will sprout extra connections to neurone replacing ones that have been destroyed

compensating for loss of neighbour- brain can re-wire itself by forming new synaptic connections close to area of damage

occurs for most part two weeks after damage happens

helps replace function but only if damaged axon + compensatory axons do similar job

If not problems can occur w/ function

Question 76

functional recovery-brain after recovery: NEURONAL UNMASKING (A01)

Answer 76

some of brain’s neurones are ‘dormant’

These neurones are alive but are not doing their specific function eg. they may fail to send messages to muscle

but when brain area becomes damaged these dormant areas become ‘unmasked’

unmasking of dormant neurones opens connections in regions of brain that are not normally activated which in time gives way to development of new structures

Question 77

functional recovery-brain after recovery: RECRUITMENT OF HOMOLOGOUS AREAS (A01)

Answer 77

opposite side of brain to perform specific tasks

eg. would be if Broca’s area was damaged on left side of brain similar area on right-side of brain would carry out its function

Question 78

factors affecting recovery of brain after trauma: age (A01)

Answer 78

deterioration of brain in old age + this therefore affects extent + speed of recovery

study by Marquez de la Plata et al found that following brain trauma older patients regained less function in treatment than younger patients + they were also more likely to decline in terms of function for 5 years following trauma

Question 79

factors affecting recovery of brain after trauma: gender (A01)

Answer 79

research to suggest that women recover better from brain injury as their function is not as lateralised

Ratcliffe et al examined 325 patients w/brain trauma for their level of response for cognitive skills to rehabilitation

patients were 16-45 years old at injury received rehabilitation at care facility + completed follow-up 1 year later

None of them had learning problems prior to trauma

When assessed for cognitive skills women performed significantly better than men on tests of attention/working memory + language whereas men outperformed females in visual analytic skills

Question 80

factors affecting recovery of brain after trauma: physical exhaustion, stress + alcohol consumption (A01)

Answer 80

function is recovered in an individual it is important to remember that often function is used w/considerable effort + although person can do task they are often fatigued by effort

Other factors such as stress + alcohol consumption can affect ability to use any function that has been regained

Question 81

factors affecting recovery of brain after trauma: evidence to support plasticity (A03) (1)

Answer 81

P: evidence to support plasticity

E+ E: Maguire et al used an MRI scanner to scan brains of London taxi drivers + found they had significantly more volume of grey matter in posterior hippocampus than matched control group- volume of this area was also positively correlated w/amount of time they had been taxi driver

L: positive as it supports idea that human brain can adapt as result of learning + experience

Question 82

factors affecting recovery of brain after trauma: plasticity has contributed to treatment + rehabilitation of brain injury patients (A03) (3)

Answer 82

P: Understanding processes involved in plasticity has contributed to treatment + rehabilitation of brain injury patients

E+ E: Following illness or injury to brain recovery tends to slow down after few weeks so forms of physical therapy are usually performed to maintain improvements in functioning

L: shows that although brain may have capacity to ‘fix itself’ to point this process requires further intervention if it is to be completely successful

Question 83

factors affecting recovery of brain after trauma: evidence to support plasticity also comes from animal studies (A03) (2)

Answer 83

P: evidence to support plasticity also comes from animal studies

E+ E: evidence of neuroplasticity
comes from an animal study conducted by Hubel + Wiesel- this study kittens had 1 of their eyes sewn up + brain’s cortical responses were analysed- found that area of visual cortex associated w/shut eye was not idle but continued to process info from open eye

L: positive as it supports idea that brain can change or adapt as result of experience

Question 84

factors affecting recovery of brain after trauma: functional recovery is affected by individual differences (A03) (4)

Answer 84

P: functional recovery is affected by individual differences

E: appears that certain individuals may have more of an ability to recover from brain trauma than others eg. Elbert et al showed that adults require far more intensive training than children after brain trauma

E: Schneider et al found that patients w/college education were seven times more likely than those who didn’t finish high school to be disability-free 1 year after brain injury

L: suggests no. of factors contribute to brain plasticity + recovery from brain trauma which makes it complex area to study

Question 85

biological rhythms (A01)

Answer 85

natural cycle of change in our body’s chemicals or functions

rhythms are governed by 2 things: body’s internal body clocks + external changes to environment

Question 86

biological rhythms: cardiac rhythms (A01)

Answer 86

cycle in biological or psychological activity that occurs once every 24 hours

most obvious example is sleep-wake cycle which occurs once every day

eg. include core body temp also follows daily rhythm as it is highest at around 4pm + lowest at around 4am

Question 87

cardiac rhythms: hormone production (A01)

Answer 87

Hormone release follows circadian rhythm eg. production + release of melatonin from pineal gland in brain follows circadian rhythm w/ peak levels occurring during hours of darkness

activating chemical receptors in brain melatonin encourages feelings of sleep

dark more melatonin in produced + when it is light again production of melatonin drops + person wakes

Question 88

cardiac rhythms: sleep-wake cycle (A01)

Answer 88

circadian rhythm not only dictates when we should be sleeping but also when we should be awake

Light + darkness are external signals that determine when we feel need to sleep + when to wake up

circadian rhythm also dips + rises at different times of day so our strongest sleep drive usually occurs in 2 ‘dips’ between 2-4 am + between 1-3 pm

Question 89

cardiac rhythms: practical application (A03) (1)

Answer 89

P: practical application

E+ E: Research into circadian rhythms provides an understanding of the consequences that occur when they are disrupted eg. night workers experience reduced concentration around 6am

L: leading to an increase in mistakes + accidents

Question 90

cardiac rhythms: small sample size (A03) (2) UNFINISHED

Answer 90

P: small sample size

Question 91

biological rhythms: infradian rhythms (A01)

Answer 91

last more than 24 hours eg. include menstruation breeding, hibernation + seasonal affective disorder

Question 92

infradian rhythms: support by theory of evolution (A03) (1)

Answer 92

P: support by theory of evolution

E+ E: eg. may have been advantageous for women to menstruate together + become pregnant at same time -In social group this would allow babies who had lost their mothers during childbirth to have access to breast milk thereby improving their chances of survival

L: suggests that synchronisation of menstrual cycle is an adaptive strategy

Question 93

infradian rhythms: menstrual cycle (A01)

Answer 93

woman’s menstrual cycle is monthly infradian rhythm that is governed by monthly changes in hormones that regulate ovulation

typical cycle lasts 28 days

During each cycle rising levels of hormone oestrogen cause ovary to release an egg

After ovulation hormone progesterone helps womb lining to grow thicker readying womb for pregnancy

If pregnancy does not occur egg is absorbed to body womb lining comes area + leaves body

Question 94

infradian rhythms: research (A01)

Answer 94

McClintock: 29 women w/irregular periods were studies

Samples of pheromones were gathered from 9 of women at different stages of their menstrual cycles via cotton pad placed in their armpits

pads were then rubbed on upper lip of other Ps

Stern + McClintock found that 68% of women experienced changes to their cycle which brough them closer to cycle of their ’odour donor’

Question 95

infradian rhythms: limitations to synchronisation studies (A03) (2) UNFINISHED

Answer 95

P: limitations to synchronisation studies

E+ E: eg. there are many factors that may cause menstrual cycle to change, including stress, extreme dieting + exercising

Question 96

ultradiation rhythms: stages of sleep (A01)

Answer 96

Stages 1: this is light sleep where person may be easily woken- alpha brain waves occur

Stage 2: Light sleep continues
Sleep spindles also occasionally occur

Stages 3 + 4: deep sleep or slow wave sleep
Delta waves occur w/lower frequency + higher amplitude difficult to wake someone at this point.

Stage 5: body is paralysed yet brain activity closely resembles that of awake brain
brain produces theta waves + eyes move around- Dreams are most often experienced during REM sleep

Question 97

biological rhythms: ultradiation rhythms (A01)

Answer 97

Ultradian rhythms are biological rhythms lasting less than 24 hours

eg. of ultradian rhythms include eye blinking, heartbeats, sleep patterns, breathing, pulse, appetite + digestion

When we sleep we go through 5 distinct stages that span about 90 minutes

cycle starts at light sleep progressing to deep sleep + then REM sleep

repeats itself about every 90 minutes throughout night typical person will go through about 5 full cycles in full night’s sleep

Question 98

ultradiation rhythms: improved understanding of age-related changes in sleep (A03) (1)

Answer 98

P: improved understanding of age-related changes in sleep

E+ E: eg. sleep scientists have observed that SWS reduces w/age leading to reduced alertness in elderly

L: suggests that knowledge of ultradian rhythms has practical value

Question 99

ultradiation rhythms: ignores individual differences (A03) (2)

Answer 99

P: ignore individual differences

E+ E: Tucker, 2007, found large differences in duration of each sleep stage in many Ps

L: makes it difficult to describe ‘normal sleep’

Question 100

endogenous pacemakers + sleep wake cycle: suprachiasmatic nucleus (SCN) (A01)

Answer 100

SCN is tiny bundle of nerve cells located in hypothalamus plays an important role in maintaining circadian rhythms eg. sleep/wake cycle SCN is damaged or destroyed, sleep becomes erratic

SCN lies just above the optic chaism receives information about light directly from this structure continues even when our eyes are closed

enabling biological clock to adjust to changing patterns of daylight whilst we are asleep

our biological clock is running slow then morning light automatically adjusts clock putting its rhythm in step w/world outside

synronisation of SCN by changes in light is known as entrainment

Question 101

endogenous pacemakers (A01)

Answer 101

internal body clocks that regulate many of our biological rhythms

Question 102

endogenous pacemakers + sleep wake cycle: pineal gland + melatonin (A01)

Answer 102

SCN passes info on day length + light to pineal gland

During night pineal gland increases production of melatonin chemical that induces sleep and is inhibited
during period of wakefulness

Melatonin has also been linked to seasonal affective disorder (SAD)

Question 103

endogenous pacemakers + sleep wake cycle: supporting evidence (A03) (1)

Answer 103

P: supporting evidence

E: support idea that SCN is key endogenous pacemaker in sleep-wake cycle comes from Morgan Studying hamsters it was found that if SCN was removed circadian sleep-wake cycle completely disappeared

E: Transplanting SCN cells from foetal hamsters to these hamsters helped to re-establish sleep-wake cycle if hamster was given transplanted SCN from mutant strain of hamster w/shorter sleep-wake cycle of 20 hours it will adopt the same activity patterns as mutant donor

L: animal studies support view that SCN is vital in maintaining sleep-wake cycle

Question 104

endogenous pacemakers + sleep wake cycle: case study of Siffre lends further support for role of SCN (A03) (2)

Answer 104

P: case study of Siffre lends further support for role of SCN

E+E: Siffre lived underground in cave in Texas for 6 months w/X external cues such as daylight- was found that his sleep-wake cycle settled to ‘free-running’ rhythm of around 25 hours- study suggests endogenous pacemakers such as SCN are important in controlling sleep-wake cycle

L: Despite absence of any exogenous zeitgebers Siffre was able to maintain relatively normal cycle

Question 105

endogenous pacemakers + sleep wake cycle: practical application (A03) (3)

Answer 105

P: real world application for role of endogenous pacemakers in circadian rhythms

E+ E: eg. our circadian rhythms affect when drugs are most affective therefore when prescribed drugs it is now advised that they are taken at different times of day to maximise their effects

L: suggests that we have an internal clock that controls our 24-hour sleep-wake cycle as medication is advised to be taken around this cycle

Question 106

exogenous Zeitgebers + sleep wake cycle: social cues (A01)

Answer 106

mealtimes, bedtimes + social events also act as zeitgeber

Research also suggests that adapting to local times for eating + sleeping is an effective way on entraining circadian rhythms + beating jet lag when travelling long distances

Question 107

endogenous pacemakers + sleep wake cycle: contradictory evidence (A03) (4)

Answer 107

P: contradictory evidence

E+ E: Folkard studied university student Kate Aldcroft who volunteered to spend 25 days in controlled environment of laboratory- During her time in lab she had no access to daylight or other zeitgebers that might have reset SCN end of 25 days her sleep-wake cycle had extended to 30 hours

L: reduces validity of role of endogenous pacemakers in sleep-wake cycle as it appears that exogenous zeitgebers are required to synchronise SCN

Question 108

exogenous Zeitgebers + sleep wake cycle: light (A01)

Answer 108

important zeitgeber in humans

It helps to maintain sleep–wake cycle by resetting SCN

Receptors in SCN are sensitive to changes in light levels during day + use this information to synchronise activity of body’s organs + glands

Light resets internal biological clock each day keeping it on 24-hour cycle

Question 109

exogenous Zeitgebers + sleep wake cycle: supporting evidence (A03) (1)

Answer 109

P: supporting evidence

E+ E: role of exogenous zeitgebers in circadian rhythm control comes from Campbell and Murphy- found that shining light on back of participants’ knees shifted circadian rhythm

L: implies that natural light plays role in ‘entraining’ our biological clocks to keep sleep-wake cycle in synchrony w/outside world

Question 110

exogenous Zeitgebers + sleep wake cycle: contradictory evidence (A03) (3)

Answer 110

P: contradictory evidence

E+ E: Miles studied young man who was blind from birth Despite exposure to social cues such as regular mealtimes his sleep/wake cycle remained abnormal

L: suggests that social cues alone are not effective in resetting biological rhythm

Question 111

exogenous Zeitgebers + sleep wake cycle: practical application (A03) (2)

Answer 111

P: practical application

E+ E: Research on exogenous zeitgebers has led to treatments for jet lag eg. Burgess et al found that exposure to bright light prior to an east-west flight reduced jet lag Ps who were exposed to bright light felt sleepier 2 hours earlier in evening + woke 2 hours earlier in morning eg. closer to local times conditions they would find after an east-west flight

L: huge benefits to the economy as preventing jet lag increases productivity eg. people are more likely to return to work earlier if they are less sleepy