Biopsychology

Question 1

Human nervous system

Answer 1

Central nervous system (CNS)
brain + spinal cord
processes + responds to info in environment
coordinates working of different organs + cells

Peripheral nervous system (PNS)
Somatic - processes your brain runs with thinking
Autonomic - processes your brain runs without thinking. Has two divisions - sympathetic (excites) + parasympathetic (calms)

Question 2

Endocrine system

Answer 2

instructs glands to release hormones into bloodstream - carried to target organs

Ovaries - oestrogen
Pituitary gland (master gland) - oxytocin
Adrenal gland - adrenaline

Endocrine + NS link: fight/flight, adrenaline released from adrenal gland - physiological effect on ANS, more specifically sympathetic nervous system. Heart rate + breathing rate increase, pupils dilate, digestion stops so energy used in survival. After danger passed, parasympathetic system calms down body.

Question 3

Dendrites + axons of motor, sensory, relay

Answer 3

Motor: short dendrites, long axon
Sensory: long dendrites, short axon
Relay: short dendrites, short axon

Question 4

Outline effect of endogenous pacemakers on sleep/wake cycle

Answer 4

Internal body clocks - regulate bio rhythms e.g. circadian rhythm + influence of suprachiasmatic nucleus (SCN) on sleep/wake cycle

SCN - tiny nerve cell bundle found in hypothalamus in each brain hemi. Nerve fibres are connected to eye cross in optic chiasm on way to visual area + SCN lies above this structure to receive info on light directly from it
Process continues when eyes are closed enabling bio clock to adjust to changing daylight levels as we sleep

DeCoursey et al (2000) destroyed SCN connections in 30 chipmunk brains + returned to natural habitat to observe for 80 days - sleep/wake cycle disappeared + by end significant proportion killed by predators - they were awake + vulnerable to attack when should’ve been asleep
Suggests there’s direct link between SCN + sleep/wake cycle + how it can influence animal’s survival chances .

Pineal gland + its relationship with melatonin. SCN passes info it receives on day length + light to pineal gland which during night increases melatonin production (chemical that induces sleep + inhibited when awake)

Question 5

Outline effect of exogenous zeitgibers on sleep/wake cycle

Answer 5

External factors in enviro that may affect bio rhythms e.g. influence of light on sleep/wake cycle. Light can reset body’s SCN + have indirect influence on key processes controlling e.g. hormone secretion + blood circulation.

Campbell + Murphy (1998) - light detected by skin receptor sites on body even when same info isn’t received by eyes.
15 pps woken at various times + light shone on back of knees – managed to produce deviation in usual sleep/wake cycle of up to 3 hours.
Suggests light doesn’t necessarily rely on eyes to influence brain.

Social cues can also impact sleep/wake cycle: 6 weeks age, circadian rhythms begin + 16 weeks most babies entrained, but schedules imposed by parents likely to be key influence e.g. adult-determined mealtimes + bedtimes.

Research suggests adapting to local times for eating + sleeping is effective way of entraining circadian rhythms + beating jet lag

Question 6

Evaluate effect of endogenous pacemakers and exogenous zeitgibers on sleep/wake cycle (1-)

Answer 6

Research shows numerous circadian rhythms in many organs + cells of body - peripheral oscillators.
Found in e.g. adrenal gland, lungs, liver + skin - highly influenced by SCN but also act independently.
Damiola et al (2000) - changed feeding patterns in mice - altered circadian rhythms of cells in liver up to 12 hours whilst leaving SCN rhythm unaffected - imply there may be many other complex influences on sleep/wake cycle apart from SCN.

Question 7

Evaluate effect of endogenous pacemakers and exogenous zeitgibers on sleep/wake cycle (2-)

Answer 7

Influence of exogenous zeitgebers may be overstated.
Studies of individuals living in arctic regions (where sun doesn’t set during summer months) show normal sleep patterns despite prolonged exposure to light.
Suggests there are occasions when exogenous zeitgebers may have minimal impact on internal rhythms.

Question 8

Evaluate effect ofendogenous pacemakers and exogenous zeitgibers on sleep/wake cycle (3-)

Answer 8

Methodological issues
Campbell + Murphy’s study yet to be replicated + other psychologists have criticised the way study was performed – implied there may have been some limited light exposure to pps eyes - acts as major confounding variable
Also, isolating the exogenous zeitgeber light gives little insight into many other zeitgebers that influence sleep/wake cycle + extent to which these may interact.

Question 9

Outline split-brain research

Answer 9

Hemispheric lateralisation - 2 hemis functionally different + certain behaviours mainly controlled by one rather than other e.g. language which is localised as well as lateralised.

Sperry’s (1968) - unique group all experienced same surgical procedure where corpus callosum cut to control frequent + severe epileptic seizures - main communication line between 2 hemispheres removed.

Allowed Sperry to see extent to which 2 were specialised with certain functions

Image / word projected to pps right visual field, processed by left hemi + same / different image projected to left visual field, processed by right hemi
Normal brain: corpus callosum immediately share info between both hemis giving complete picture of visual world.
Split brain patient: presenting image to 1 hemi meant info not conveyed to other.

When pic shown to patients r.v.f ppt easily described what was seen but same pic shown to l.v.f could not describe what was seen + typically reported there was nothing there.
Language mainly processed in left hemi so pps inability to describe objects in l.v.f processed in right hemi, was due to lack of language centres in right hemi.
Normal brain: messages from right relayed to language centres in the left but not case for these pps

Question 10

Evaluate Sperry’s research (1+)

Answer 10

Sperry’s study produced impressive + sizeable findings - left hemi more geared towards analytic + verbal tasks whilst right more geared at spatial tasks
Right hemi only produce rudimentary words but adds emotional + holistic content to language.
Left is analyser, right is synthesiser - key contribution to our understanding of brain processes.

Question 11

Evaluate Sperry’s research (2+)

Answer 11

Good methodology - exp used highly specialised + standardised procedures.
Pps stare at fixation point, whilst one eye blindfolded. Image projected flashed up for a fraction of second meaning split brain patient would not have time to move eye across image + so spread info across both sides of visual field + so both sides of the brain.
Ensured only 1 hemi receiving info at a time
Useful + well-controlled procedure - internal validity

Question 12

Evaluate Sperry’s research (3-)

Answer 12

Issues with generalisation
Only 11 ppl took part in all variations of basic procedure, all of whom had a history of epileptic seizures - this may have caused unique changes in brain that may have influenced findings.
Some participants also experienced more disconnection of 2 hemis as part of their surgical procedure than others.
Finally, control group used made up of 11 people who had no history of epilepsy - could be seen as inappropriate

Question 13

Outline brain scanning techniques (fMRI)

Answer 13

Functional magnetic resonance imaging (fMRI)
Detects changes in blood oxygenation + flow happening due to neural activity in specific parts of brain = one area more active = consumes more oxygen - to meet increased demand blood directed to the area (haemodynamic response)

Produces 3D images showing brain parts involved in particular mental process - has important implications for understanding of localisation of function .

Question 14

Evaluate fMRI (1+)

Answer 14

Unlike other scanning techniques e.g PET it does not rely on radiation
If administered correctly its virtually risk free, non-invasive + straight forward to use

High spatial resolution showing detailed images by mm + provide clear picture of how brain activity is localised.

Question 15

Evaluate fMRI (2-)

Answer 15

fMRI is expensive in comparison

Can only capture clear image if person stays perfectly still.
Has poor temporal resolution - around 5 second time lag behind image on screen + initial firing of neuronal activity.

Can only measure blood flow in brain - cannot tell us activity of individual neurons - difficult to tell exactly what kind of brain activity is represented on screen.

Question 16

Outline brain scanning techniques (EEG)

Answer 16

Electroencephalogram (EEG)
Measures electrical activity within brain via electrodes fixed to individual’s scalp using skull cap.
Scan recording represents brain wave patterns generated from actions of millions of neurons - provides overall account of brain activity.
Often used by clinicians as diagnostic tool - unusual arrhythmic patterns of activity (no particular rhythm) may indicate neurological abnormalities e.g. epilepsy / tumours / sleep disorder

Question 17

Evaluate EEG (1+)

Answer 17

Proved to be valuable in diagnosis of conditions
E.g. epilepsy - disorder characterised by random bursts of activity in brain easily detected on screen. Has contributed to our understanding of stages involved in sleep.

Has extremely high temporal resolution (unlike fMRI) -can accurately detect brain activity at resolution of single millisecond + even less in some cases.

Question 18

Evaluate EEG (2-)

Answer 18

Generalised nature of info received limits EEG
It’s signal not useful for pinpointing exact source of new activity + it doesn’t allow researchers distinguish between activities originating in different but adjacent locations.

Question 19

Outline brain scanning techniques (ERP)

Answer 19

Event related potentials (ERP)
Within EEG data are all neural responses associated with specific sensory, cognitive + motor events that could be of interest.
Researchers developed way of isolating these responses - all extraneous brain activity from original EEG recording filtered out leaving responses relating to e.g. performance of specific task.
What remains are ERPs: types of brain waves triggered by particular events. Research has revealed many different forms of ERP + their links to cognitive processes e.g. attention

Question 20

Evaluate ERP (1+)

Answer 20

Much more specific when measuring neural processes than raw EEG data could ever achieve.
ERP’s are derived from EEG measurements also have excellent temporal resolution compared to fMRI
This led to widespread measurement of cognitive functions + deficits.

Question 21

Evaluate ERP (2-)

Answer 21

Lack of standardisation in methodology between different research studies make it difficult to confirm findings.

Also, to establish pure data in ERP studies, bg noise + extraneous variables must be completely eliminated -not always that easy to achieve.

Question 22

Outline brain scanning techniques (post mortem examinations)

Answer 22

Analysis of person’s brain following death
Person’s brain more likely to be used if they experienced rare + unusual mental disorder during their lifetime.
Damaged brain areas examined after death to establish likely cause of affliction person suffered - may also involve comparison with a neurotypical brain to see extent of difference.

Question 23

Evaluate post mortem examinations (1+)

Answer 23

Post mortem evidence vital in providing foundation for early understanding of key brain processes.
Broca + Wernicke both relied on post mortem studies to establish links between language, brain + behaviour decades before neuroimaging became possible.
Studies improve medical knowledge + help generate hypotheses for further study.

Question 24

Evaluate post mortem examinations (2-)

Answer 24

Causation is issue within these investigations.
Observed damage to brain may not be linked to deficits under review but to some other unrelated trauma / decay.

Also post mortem studies raise ethical issues of consent from patient before death - may not be able to provide informed consent e.g.HM lost ability to form memories + not able to provide such consent - nevertheless post mortem research has been conducted on his brain.

Question 25

Outline research into plasticity of the brain including functional recovery

Answer 25

Plasticity - brains tendency to change + adapt functionally + physically due to experience + learning.

As we age rarely used connections deleted + frequently used strengthened - synaptic pruning. At anytime in life existing neural connections can change / new neural connections can be formed due to learning experiences.

Maguire et al 2000 - London taxi driver brains - found significantly more volume of grey matter in posterior hippocampus than in matched control group. Part associated with development of spatial + navigational skills.
As part of training taxi drivers must take test called The Knowledge - assesses recall of city streets + possible routes. Result of learning experience is to alter structure of taxi drivers brains - longer they had been in job the more pronounced the structural differences were.
Similar results found by Draganski et al (2006) - imaged brains of medical students 3 months before + after final exams. Learning induced changes occurred in posterior hippocampus + parietal cortex presumably as a result of the exam.

Functional recovery - form of plasticity + brain’s ability to redistribute functions usually performed by damaged areas to healthy brain areas after trauma
Process occurs quickly after trauma (spontaneous recovery).
Secondary neural pathways activated to enable functioning to continue in same way as before - process supported by # of structural changes in brain:

Axonal sprouting: growth of new nerve endings connecting to other undamaged nerve cells to form new neuronal pathways.

Reformation of blood cells

Recruitment of homologous areas on the opposite side of the brain to perform specific tasks.

Question 26

Evaluate research into plasticity of the brain including functional recovery (1-)

Answer 26

Functional plasticity reduced with age.
Brain has greater propensity for reorganisation in childhood - constantly adapting to new experiences + learning.
Yet Bezzola et al (2012) - 40h of golf training produced changes in neural representation of movement in pps aged 40 to 60. Using fMRI, reduced motor cortex activity in the novice golfers found compared to control group, suggesting more efficient neural representations after training.
Shows plasticity does continue throughout lifespan

Question 27

Evaluate research into plasticity of the brain including functional recovery (2)

Answer 27

Practical applications.
Understanding processes involved in plasticity has contributed to field of neurorehabilitation. Following illness / injury to brain, spontaneous recovery tends to slow down after a number of weeks so forms of physical therapy may be required to maintain improvements in functioning.
E.g. movement therapy + electrical stimulation of brain to counter deficits in motor and/or cognitive functioning that may be experienced following e.g. a stroke.
Although brain has capacity to fix itself to a point, process requires further intervention to be completely successful

Question 28

Evaluate research into plasticity of the brain including functional recovery (3-)

Answer 28

However brain’s ability to rewire itself can have maladaptive behavioural consequences.
E.g. prolonged drug use shown to result in poorer cognitive functioning + increased risk of dementia later in life (Medina et al 2007).
Also, 60 to 80% of amputees known to develop phantom limb syndrome - continued experience of sensations in missing limb as if it was still there. Sensations usually unpleasant, painful + thought to be due to cortical reorganisation in somatosensory cortex that occurs due to limb loss.

Question 29

Outline localisation

Answer 29

Localisation - different brain areas responsible for different processes
19th century Broca + Wernicke found specific brain areas associated with physical + psych functions - before this ppl supported holistic theory – all brain parts involved in processing thought.
Certain area damaged through illness / injury - function associated with area also affected.

Lateralisation - some physical + psych functions controlled by particular hemi.
LHS controlled by right hemi + RHS controlled by left.

Outer layer cerebral cortex subdivided into 4 lobes:
Frontal lobes - has motor area controlling voluntary movement in opposite side of body. Damage may result in loss fine movement control

Parietal lobes - front has somatosensory area, sensory info from skin is represented.

Occipital lobe - back of the brain, visual area. Each eye sends info from r.v.f to left visual cortex + from l.v.f to right visual cortex - means damage to left hemi, e.g. can produce blindness in part of r.v.f of both eyes.

Temporal lobes - auditory area, analyses speech-based info. Damage may cause partial hearing loss + damage to Wernicke’s area affect ability to comprehend language.

Language restricted left side of brain in most. 1880s - Broca found Brocas area (language production)
Wernicke found Wernicke’s area (language comprehension)
Damage causes Brocas aphasia (lack of fluency /slow speech) + Wernicke’s aphasia (nonsense words)

Question 30

Evaluate the extent to which the brain is localised (1+)

Answer 30

Brain scan evidence of localisation.
Range of evidence that many neurological functions are localised
Peterson at al (1988): brain scans to demonstrate how Wernicke’s area active during listening task + Broca’s area active during reading task - suggests areas of brain have different functions.
Also LTM study by Tulving et al (1994): semantic + episodic memories reside in different parts of prefrontal cortex.
Several highly objective methods for measuring activity in brain exist - provides valid evidence for localisation of brain function.

Question 31

Evaluate the extent to which the brain is localised (2-)

Answer 31

However, Lashley’s (1950) research suggests learning processes are not localised but more holistic.
Lashley removed cortex areas (between 10 + 50%) in rats learning a maze. No area proven to be more important than another in terms of rat’s ability to learn maze + process of learning seemed to require every part of cortex, rather than particular area.
Suggests learning too complex to be localised + requires involvement of whole of brain.
However, some argue generalising findings conducted on rats to humans is not appropriate.

Question 32

Evaluate the extent to which the brain is localised (3-)

Answer 32

Cortical remapping / plasticity.
When brain damaged + particular function been lost, rest of brain appears able to reorganise itself in attempt to recover lost function. Lashley described this as the law of equipotentiality - surviving brain circuits contribute so same neurological action is achieved.
Does not happen every time, but there are several documented cases of stroke victims able to be recover those abilities seemingly lost due to illness.

Question 33

Outline circadian rhythms

Answer 33

Circadian rhythms - bio rhythms subject to 24-hour cycle. Regulates sleep/wake cycle + changes in core body temp

Siffre’s cave study - effects of extended periods underground on own bio rhythms. Deprived of exposure to natural light + sound but access to food + drink, Siffre resurfaced mid Sept 1962 after 2 months in Southern Alps caves believing it to be mid-August.

Decade later performed same exp but for 6 months in Texan cave. Each cave free-running bio rhythm settled down beyond usual 24h (around 25h ) but did continue to fall asleep + wake up on regular schedule.
Suggests ‘natural’ sleep/wake cycle may be slightly longer than 24 hours its entrained by exogenous zeitgebers associated with 24 hour day e.g. # of daylight hours + typical meal times.

Question 34

Evaluate circadian rhythms (1-)

Answer 34

Case studies + small samples
Sleep/wake cycle studies tend to involve small groups / individuals like Siffre - may not be representative of wider pop + limits extent meaningful generalisations can be made.
Siffre observed in most recent cave experience that at age 60, his internal clock ticked much slower than when he was young - so even if same person involved there are factors preventing general conclusions to be made.

Question 35

Evaluate circadian rhythms (2-)

Answer 35

Findings derived limited due to poor control.
Although pps deprived of natural light, still had access to artificial light - Siffre turned on lamp every time he woke up + remained on until he went to bed
Assumed artificial light have no effect on free-running bio rhythms but in other studies, researchers able to adjust participants’ circadian rhythms from 22 to 28 hours using dim lighting.
Limited internal validity of Siffre’s research.

Question 36

Evaluate circadian rhythms (3+)

Answer 36

Practical application to drug treatments.
Circadian rhythms coordinate # different processes e.g. heart rate, digestion + hormone levels. In turn effect on pharmacokinetics – how well drugs absorbed + distributed in body
Research shows certain peak times during day / night when drugs likely to be most effective – led to development of guidelines on timing of drug dosing medications e.g. anti-cancer, cardiovascular + anti-epileptic drugs (Baraldo 2008).
Useful application + external validity.

Question 37

Evaluate circadian rhythms (4+)

Answer 37

Application on shift work.
Night workers engaged in shift work experience reduced concentration around 6 in morning (circadian trough) so mistakes + accidents more likely to occur (Bolvin et al 1999).
Research - shift workers three times more likely to develop heart disease, maybe cus stress of adjusting to different sleep/wake patterns + lack quality sleep during day - research has economic applications + how to best manage worker productivity.

Question 38

Outline ultradian rhythms

Answer 38

bio rhythm with frequency of more than one cycle in 24 hours e.g. stages of sleep
5 distinct stages of sleep together span approx 90 mins - each stage characterised by different levels of brainwave activity + monitored using EEG.

Stages 1 + 2: light sleep - person easily woken. At beginning of sleep, brainwave patterns become slower + more rhythmic (alpha waves), becoming even slower as sleep becomes deep (theta waves).

Stages 3 + 4 involve delta waves which slower + have greater amplitude than earlier wave patterns. Where deep sleep occurs + more difficult to rouse someone at this point.

Stage 5: REM sleep, where body is paralysed yet brain activity speeds up significantly in way resembling awake brain. REM (rapid eye movement) - fast, jerky activity of eyes under eyelids. REM activity during sleep highly correlated with experience of dreaming

Question 39

Evaluate ultradian rhythm (1+)

Answer 39

Supporting evidence for stages of sleep.
Dement + Kleitman (1957) monitored sleep patterns 9 adult pps in sleep lab, brainwave activity recorded on EEG + researchers controlled coffee + alcohol effects
Brain activity varied according to how vivid dreams were + pps woken during dreaming reported very accurate recall of dreams.
Replications of investigation noted similar findings, though small size of original sample criticised by some. Nevertheless study suggests REM (dream) sleep is important component of ultradian sleep cycle.

Question 40

Evaluate ultradian rhythm (2-)

Answer 40

Way research conducted tells little about ultradian rhythms in humans.
When investigating sleep patterns, pps subjected to specific level of control + attached to EEG monitors - invasive for ppt, leading them to sleep in way that does not represent ordinary sleep cycle - makes investigating ultradian rhythms difficult as lack of ecological validity can lead to false conclusions being drawn.

Question 41

Outline infradian rhythms

Answer 41

bio rhythm with frequency less than one cycle in 24 h e.g. menstruation. Typical cycle 28 days complete.

Oestrogen: rising levels make ovary develop egg + release through ovulation
Progesterone: womb lining grow thicker to ready body for pregnancy- if doesn’t occur egg absorbed into body + womb lining leaves body (menstrual flow.)

McClintock (1998): how menstrual cycle synchronise due to female pheromones influence. 29 women with history of irregular periods, 9 of them pheromone samples gathered at different stages of cycle with cotton pad on armpit.
Worn at least 8 hours, treated with alcohol + frozen to be rubbed on upper lip of the pps.
Day 1 pads from start of cycle applied to all 20 women, day 2 pad from second day etc
68% experienced changes to cycle - brought closer to odour donor cycle

Seasonal affective disorder (SAD): type of infradian rhythm (circannual rhythm) + depressive mental disorder with seasonal pattern.
Persistent low mood + general lack of activity/interest in life, triggered during winter months when daylight hours shorter. May be due to disruption to sleep/wake cycle caused by long daily darkness periods

Melatonin also causes SAD: during night pineal gland secretes melatonin until dawn when there is increase in light, but lack of light in winter means secretion process continues for longer – knock on effect on serotonin production in brain, chemical linked to onset of depressive symptoms.

Question 42

Evaluate Infradian rhythms (1-)

Answer 42

Methodological limitations in synchronisation studies.
Many factors may affect women’s cycle e.g. stress / diet changes - act as confounding variables.
So any pattern of synchronisation seen in McClintock’s study is no more than what would have been expected to occur by chance - what have we actually learnt from this research?
Research also involves small samples + relies on them to self-report onset of their cycle - subject to social desirability bias + dishonesty.
Reliability is questionable

Question 43

Evaluate Infradian rhythms (2+)

Answer 43

Practical application for SAD.
One of most effective treatments is phototherapy – light box stimulates very strong light in the morning + evening - thought to reset melatonin production.
Relieved symptoms in up to 60% of patients (Eastman et al 1998) but same study recorded placebo effect of 30% using sham negative ion generator - pps told it was another form of treatment.
Despite some practical application + external validity to SAD later findings cast doubt on chemical influence of phototherapy.