Biopsychology

brain:

-very advanced cerebral cortex (grey matter)

-2 symmetrical hemispheres w/ 4 lobes: frontal, parietal, temporal & occipital

-below cerebral cortex, human behaviour is instinctive

spinal cord:

-white bundle of nerves (40cm long) passing messages to & from brain

-involved w/ startle responses

somatic nervous system:
-concerned w/ environmental stimuli
-produces voluntary responses of skeletal muscles
-consists of nerves (excitatory neurotransmitters) which carry messages to ears, skeletal muscles, skin & eyes to give CNS experience of environment
autonomic nervous system:
-involuntary movement (unconsciously) from non-skeletal muscles which control bladder, digestion etc
-has both excitatory (sympathetic NS) & inhibitory (parasympathetic NS) neurotransmitters

parasympathetic: activates after danger passes to return body to homeostasis, vital to conserve energy

sympathetic: 'fight or flight' when under stress to aid survival e.g. pupils dilate, Hr increases, respiratory increases.

-afferent neurons; they move nerve impulses towards CNS/central organ
-receives stimulus from sensory receptors e.g. eyes, skin etc
-info enters through dendrites (usually long), passes to cell body (control centre), then sent through axon (usually short) to axon terminal
-all in electrical impulses, flowing 1 way only

-responsible for connecting sensory & relay
-located in CNS
-short dendrites & axons

excitation = increasing charge on post-synaptic neuron, making it more positively charged & more likely to fire
inhibition = decreasing charge on post-synaptic neuron, making it more negatively charged & less likely to fire

Hypothalamus = stimulates & controls release of hormones from pituitary gland
Pituitary gland = 'master gland' controls all other glands e.g. thyroid stimulation hormone signals action in thyroid, ATCH signals action in adrenal glands. TSH & ATCH hormones.
Thyroid gland = regulates metabolism & converts food into energy for muscles. Thyroxine hormone.
Parathyroid gland = increases concentration of calcium in blood from kidneys/bones. Parathormone hormone.
Pancreas = promotes absorption of glucose from blood into fat, liver & skeletal muscle cells. Insulin hormone.
Adrenal glands = fight or flight response. Adrenaline & Noradrenaline hormone.
Ovaries = develops/regulates reproductive system & secondary sexual characteristics. Oestrogen & Progesterone hormones.
Testes = develops reproductive system & secondary sexual characteristics. Testosterone hormone.
Pineal gland = regulates sleep-wake cycle. Melatonin hormone.

MOTOR AREA = found in frontal lobe, regulates movement. damage may hinder control of fine movements.

SOMATOSENSORY AREA = found in parietal lobe, processes sensory info. amount of this area devoted to certain body part will decide its lvl of sensitivity.

VISUAL AREA = found in occipital lobe, receives + processes visual info. eye sends info to & from right + left visual fields, so damage in either hemispheres can produce blindness in both eyes.

AUDITORY AREA = found in temporal lobe, analyses speech. damage may result in hearing loss.

BROCAS AREA = (language centre) found in frontal lobe, left hemisphere & concerned w/ speech production. damage may result in hearing loss.

WERNICKES AREA = (language centre) found in temporal lobe, circling auditory cortex in left hemisphere, functions language comprehension. damage in this area may cause inability to comprehend speech.

Broca's area = left hemisphere, responsible for speech production. damage can cause Broca's Aphasia; slow & influent speech. different words are damaged, so some are still fine, but some classes such as conjunctions cant be spoken.
Wernicke's area = left hemisphere, W found patients / damage in area close to auditory cortex (left temporal lobe) had inability to comprehend words & locate words they needed.

ARGUMENTS FOR
brain scan evidence = used brain scans & found Broca's area active through listening task & Wernicke's area active through reading task.
neurosurgical evidence = 44 OCD patients had cingulotomy to cut cingulate gyrus & 1/3 patients improved, showing symptoms of mental disorders are localised.
Clive Wearing case = damaged hippocampus.
ARGUMENTS AGAINST
rats running mazes = 10-50% of rats cortex removed, which had no effect on their ability on completing the maze, showing no particular area was important in learning, & learning is too complex to be localised...holistic/multifunctional.
plasticity = evidence shows when brain becomes damaged, its able to repair itself & recover function e.g. stroke victims being able to recover speech production.

-brain can recover after illness/injury (neural plasticity) & unaffected areas (healthy) can compensate for lost/damaged areas
-this can happen quickly after trauma, but after several weeks/months may need rehabilitative therapy for further recovery.
HOW IT WORKS
reorganises/rewires by forming new synaptic connections near damaged area & secondary pathways are activated to enable functioning to continue.
-axonal sprouting: new nerve endings connecting w/ undamaged nerve cells, forming new neuronal pathways.
-reformation of blood vessels.
-recruitment of homologous (similar) areas: areas on other side of brain take over specific tasks.
RESEARCH
-17yr old boy had left hemisphere removed at 2yrs old, due to non-cancerous tumour.
-received intensive rehabilitation, improving lang. fluency by age 5
-at 17yrs, scans found minor language problems

PRACTICAL APPLICATION
contributed to neurorehabilitation, & understanding of spontaneous brain recovery slowing down after a few weeks means intervention can be offered at the right time to aid recovery
NEGATIVE PLASTICITY
maladaptive effects of rewiring include prolonged drug use causing poorer cognitive functioning & risk of future dementia, as well as 60-80% amputees experiencing phantom limb syndrome (uncomfortable continued sensation in lost limb)
INDUVIDUAL DIFFERENCES
age: older patients w/ brain trauma regained less recovery in treatment than younger patients, who're also less likely to decline in function in 5yrs following trauma, however, challenging research found w/ fMRI that motor cortex activity in 40yr olds was worse than 60yr olds.
gender: women suggested better recovery as their function isnt as lateralised
education: the more time damaged patients spent in education (cognitive reserve), greater chances of disability-free recovery

- tested hemispheric lateralisation using visual & tactile tasks, using T-scope to individually test the hemispheres.
- asked to focus on 'fixation point', followed by image/word flashed for 1/10 sec to one or both visual fields.
-non-verbal processing was also tested by allowing participants to pick up/match objects out of sight.
- in normal brain: corpus callosum would share info between both hemispheres, in split-brain patient, this info couldnt be conveyed between hemispheres.

1)HEMISPHERIC LATERALISATION
when picture/word projected to left hemisphere (right visual field) they could easily name, when same was done to right hemisphere (left visual field) they couldnt.
-this shows language is processed in left hemisphere & can only name things w/ right visual field
2)VERBALISATION
unable to describe what's shown to left visual field (right hemisphere) but could use left hand to point out
-shows right hemisphere still processed info but couldnt verbalise.
3)HEMISPHERES WORK SEPARATELY & DRAWING ABILITY DOMINANT IN RIGHT HEMISPHERE
when 2 pictures/words projected at same time on either side of visual field, they could name image but when asked to draw w/ their left hand, they would draw the image they didnt name, but the other one they were shown.
-shows hemispheres work separately

METHODOLOGY
STRENGTH equipment: use of specialised scientific equipment can objectively measure the lateralisation of function as speed of which images were displayed were too quick for split-brain patients to move eyes across to other image, raising internal validity.
STRENGTH standardised procedure: using the same equipment, same tasks given, allowing reliability to be checked, consistent evidence of left hemisphere being language dominant has been found.
WEAKNESS control group: he was comparing split-brain patients w/ epilepsy history to ppl w/ no epilepsy history, so you could argue the differences could be explained by unique brain changes.
WEAKNESS small sample: hard to generalise to general population, but there are limited amount of 'split-brain' patients available, so this is unavoidable.
WEAKNESS artificial settings: in real life a severed corpus callosum can be compensated by using both eyes, so we cant generalise findings to how split-brain patients function on everyday basis.
USEFULNESS
-better understanding: we now know a lot more about how there is a lateralisation of function & how each hemisphere has certain brain processes.
-over exaggeration of hemispheres: neuroscientists argue that in 'normal brain' both hemispheres are in constant communication & behaviours associated w/ particular hemisphere can easily be performed by other when required.

Functional Magnetic Resonance Imaging: assesses changes of blood oxygenation/flow caused by neural activity in specific parts of brain, as active part will require increased oxygen & blood flow (haemodynamic response). it produces 3D activation maps, detailing which parts are involved w/ mental processes.

STRENGTHS

-straightforward & risk free, instead of relying on radiation which can be harmful

-high spatial resolution (by the mm) so we can see exactly what activity is localised

WEAKNESSES

-expensive compared to other neuroimaging & requires person to stay completely still

-poor temporal resolution as it shows brain activity 4-5 secs after its occurred, so we could misinterpret activity

-cant tell us exact activity of neurons, just blood flow, so we cant distinguish what activity is being shown

Electroencephalogram: measures electrical brain activity via electrodes on a skull cap. the scan produces brainwave patterns through 4 main EEG waves - alpha, beta, theta & delta, which can vary in amplitude (intensity/size) & frequency (speed/quantity). they are often used as diagnostic tools for uncovering arhythmic patterns signalling epilepsy, sleep disorders etc.
STRENGTHS
-valuable for diagnosing conditions
-contributed to understanding of sleep stages/sleep problems
-high temporal resolution, shows real-time
WEAKNESSES
-cant detect deeper brain regions such as the hippocampus, meaning we cant detect potential problems
-hard to pinpoint exact source of neuron activity, so we cant distinguish where the brainwaves originate from

Event-related potentials: uses electrodes attached to skull cap to look at how EEG brainwaves/activity change in response to stimulus presented to person, & which types of brainwaves are triggered by particular events. stimuli will be presented 100's times & an average response is taken (statistical averaging technique).
STRENGTHS
-EEG's being too general are solved by ERP's as they specifically measure neural processes
-continuous measure of processing a response to stimuli, so collects quant. data
-mental issues such as phobias have been identified through finding a greater amplitude of activity in phobic ppl when shown feared image compared to non-phobic.
WEAKNESSES
-lack of standardisation of methodology between different ERP studies, so lower reliability
-cant eliminate all background noise/extraneous material, so we cant establish pure data, lowering validity

Post-mortem examinations: the analysises structure of the brain after death, usually brains w/ rare disorders/deficits during the lifetime are used for this to examine the damaged area, distinguishing if it could have caused the suffering. this may be compared to normal brain to see differences.
STRENGTHS
-vital in foundations of exploring key brain processes e.g. Broca's & Wernicke's area
-improves medical knowledge & generates hypotheses for further research e.g. transexuals found to have larger area of brain associated w/ gender
WEAKNESSES
-causation issues as damage may not be linked to deficits, but unrelated trauma/decay e.g. drugs & age can affect brain tissue
-ethics are of concern because patient may have such a significant brain abnormality they're unable to consent to post-mortem examination before death (too ill)

-endogenous pacemakers is internal body clock setting many bodily rhythyms.
-the suprachiasmatic nucleus (SCN) is what affects our sleep/wake cycle, & is a bundle of nerves located at hypothalamus at back of brain.
-its located just above optic area, meaning it can directly receive light stimuli & pass it to pineal gland, where melatonin can be produced (more at night, less in day).
-without light, SCN generates rhythm from its protein production & once certain level has been reached, message for melatonin production will be sent to pineal gland, e.g. blind ppl operate on this.

the sleep-wake cycle occuring once every 24hrs where there are differences in lvls of consciousness...sleeping at certain time every 24hrs & conducting activities in between. daylight is exogenous zietgeber effect.
RESEARCH: Siffre, Cave study
-spent 2months in cave w/ no clock, calendar, natural light/sound, but access to food & drink, only ate when his body 'told him to'.
-relied on endogenous pacemaker (circadian rhythm)
-when resurfaced, lack of external cues made him think it was 1 month earlier/day was longer than it was.
FINDINGS:
-repeated study for 6 months & similarly found 'free running' circadian rhythm was 25hrs, only 1 hr over.

WEAKNESSES
-small sample: tends to involve small groups/individual, therefore not representative & lowers generalisability.
-confounding variables: both studies had access to artificial light, which more recent research has found to have an effect on the circadian rhythm, lowering validity.
-individual differences: natural preferences ('lark'/'owl'), age & innate differences can effect cycle length, further lowering generalisability.
STRENGTHS
-practical applications: night shift works have disrupted rhythms, leading to reduced concentration at approx. 6am, which has been linked to mistakes made at work & their poor health. highlights economic implications as adjustments can be made to increase health & productivity amongst workers.

MORGANS HAMSTER STUDY
-hamsters bred to have abnormal SCN of 20hrs, & these SCN cells were then transplanted into normal hamster brains.
-they (normal hamsters) adopted 20hr cycle & also the new daytime activities of abnormal hamster donors.
FINDINGS
-shows significant role of SCN in the biological circadian rhythm (sleep/wake).
EVALUATION
-ethical issues w/ questionable animal research & generalising to humans.

-external cues, such as light which is important environmental factor in resetting our biological clock (entrainment).
-light passes through retina, passing info to SCN
SUPPORTING RESEARCH: Campbell & Murphy
15 participants woken up at various times & had light shone through the back of their knees.
FINDINGS
-sleep/wake cycle affected by 3 hours in some cases
EVALUATION
-issues w/ method as limited light would have been exposed to their eyes (confounding variable) lowering validity.

-lasts longer, women's period has typical 28 day cycle (21-35 days)
-1/2 way through ovulation, oestrogen is at highest point, after egg is released, progesterone increases, priming for possible embryo development/preparing womb for pregnancy by thickening blood.
-when pregnancy doesnt occur, egg absorbes to lining, which is then shed, causing menstrual flow.
-exogenous zietgebers can also have some affect e.g. lack of light.

REINBURG: cave study
-female spent 3 months in cave w/ small lamp.
-cycle shortened from 28 to 25.7 days
-shows lack of light affects cycle
MCCLINTOCK & STERN: pheromones
-sweat (pheromones) from pads of women at different stages of cycle (control group) given to 20 women on each day of their cycle (experimental group).
-females given pad from women who were about to ovulate experienced shorter cycles & vice versa.
-68% of experimental group experienced changes bringing them closer to 'sweat donor' (synchronisation).
-shows why females living together experience similar cycles

EVALUATION
STRENGTHS
-evolutionary advantage: synchronisation of pregnancies means childcare can be shared between women who give birth at same time, due to lactating (milk) & releasing oxytocin at same time, improving bonds to babies.
WEAKNESSES
-individual differences/method issues: many confounding variables e.g. stress, diet & exercise can affect a cycle & using small sample of self-reporting women means other factors could effect cycle, making alleged cause of pheromones questionable.
-replication: repeated research has reported no synchronisation, lowering reliability.
-animal studies: pheromone knowledge predominantly comes from animal sex selection, so we cant assume this is a definite affect on human behaviour, lowering validity.

-occurs less than every 24 hrs
-typical sleep cycle: stages 1-4, back to stage 2 & finally to REM.
-one cycle lasts typically 90 mins, cycle repeated 4-5 times
-stage 1 = high frequency, low amplitude sleep
-stage 4 = delta waves, Hr & blood pressure fall, muscles relax, lasts approx. 30 mins.
-stage 1-4 = approx. 1 hour
-after this, we go back down to stage 2.
-usually just after 1hr, we reach REM (rapid eye movement, paralysed body, dreaming).
-big individual differences, as well as age factors.

KLIETMAN: sleep stages
-participants in lab reported when they would sleep & would be connected w/ EEG's (they werent allowed caffeine).
FINDINGS
-participants could recall dreams when waken from REM, but not other stages, other studies have shown dreams mostly occur in REM, but individual differences exist.
-participants fell into own pattern, going into REM from every 70-104 mins (92 min AVG), other studies found REM occurs approx. every 90 mins, but individual differences exist.
DEMENT: role of REM
-compared REM-deprived group w/ NREM-deprived group
FINDINGS
-REM-deprived more irritable, aggressive, unfocused, showing role of REM on mental health
GARDNER
-stayed awake for 264 hrs
-experienced blurred vision & disorganised speech
FINDINGS
-after sleeping just 15 hrs, he recovered: 25% overall sleep, 70% stage 4, 50% REM, little of other stages.
-shows flexibility in the sleep stages & variable nature of the ultradian rhythm.

KLIETMAN: sleep stages
-participants in lab reported when they would sleep & would be connected w/ EEG's (they werent allowed caffeine).
FINDINGS
-participants could recall dreams when waken from REM, but not other stages, other studies have shown dreams mostly occur in REM, but individual differences exist.
-participants fell into own pattern, going into REM from every 70-104 mins (92 min AVG), other studies found REM occurs approx. every 90 mins, but individual differences exist.
DEMENT: role of REM
-compared REM-deprived group w/ NREM-deprived group
FINDINGS
-REM-deprived more irritable, aggressive, unfocused, showing role of REM on mental health
GARDNER
-stayed awake for 264 hrs
-experienced blurred vision & disorganised speech
FINDINGS
-after sleeping just 15 hrs, he recovered: 25% overall sleep, 70% stage 4, 50% REM, little of other stages.
-shows flexibility in the sleep stages & variable nature of the ultradian rhythm.

WEAKNESSES

-individual differences: there are many innate differences in sleep cycles (70 - 104 hrs), so they need to be accounted for & focussed on when conducting sleep cycle research.

-lack of ecological validity: invasive & artificial situation of EEG cap being used & high degree of control doesn't reflect what an ordinary nights sleep would be.

-flexible: flexibility of stages exhibited by Gardner shows stages arent as fixed as initially proposed, however, Gardners individual experience cant be generalised to general population.