Biological Psychology

Question 1

Localisation of function in the brain.

Answer 1

This is when specific functions have specific locations in the brain.
Some physical and psychological functions may be dominated by one hemisphere (side of the brain) this is called lateralisation. (activity on left usually controlled by right and likewise)
- Motor centre
-Somatosensory centre
-visual centre
-Auditory centre
-Language centres

Question 2

Motor centre

Answer 2

This generates voluntary motor movements and is located at the back of the frontal lobe in both hemispheres. Right hemisphere controls left side of the body and likewise for the left. Damage to this centre can cause loss of movement

Question 3

Somatosensory centre

Answer 3

This is responsible for detecting sensory information from the skin (e.g. touch and pain) localises to specific body regions. it is found at the front of the parietal lobe in both hemispheres, brain receives info from opposite side of the body.

Question 4

Visual centre

Answer 4

This is responsible for processing visual information received by the retina and transmitted via optical nerve, it is located in the occipital lobe at the back of the brain and the information in the left visual field is sent to the right visual cortex (right visual field to left visual cortex)

Question 5

Auditory centre

Answer 5

The Auditory centre is responsible for processing auditory information recieved by the cochlea and transmitted via the auditory nerve, it is located in the temporal lobe in either side of the brain.

Question 6

Language centres

Answer 6

There are two language centres in the brain which are both restricted to the left hemisphere.
Broca’s area which is responsible for speech production (found in the left frontal lobe) - damage to this area may lead to problems producing speech
Wernicke’s area is responsible for understanding language and is found in the left temporal lobe- damage to this area may lead to difficulties understanding language or producing language that makes sense.

Question 7

AO3 for Localisation of function:

Answer 7

Support for localisation of function comes from brain scan research,
Further support comes from case studies of brain damaged individuals
Evidence against localisation of function comes from animal research

Question 8

Evidence to support localisation of function comes from brain scans.

Answer 8

Brain scans have demonstrated how Wernicke’s area was present during an active listening task whereas Broca’s area was active during a reading task. (Tulving also found that episodic and semantic memories were recalled from different parts of the prefrontal cortex) this is positive as there is a wide range of research to support the idea that specific functions have specific locations in the brain.

Question 9

Evidence to support comes from brain damaged patients from case studies.

Answer 9

Many of Broca’s patients suffered damage to Broca’s area and developed a condition called Broca’s aphasia whereby they have difficulty producing speech, additionally Wernicke’s patients suffered damage to Wernicke’s area who had no problem producing speech but had problems with understanding speech, this is positive as it supports specific functions are localised to specific brain areas.

Question 10

Evidence against LOF comes from animal studies.

Answer 10

It was found when 10-50% of the cortex was removed in rats learning a maze it was found that no one area was important than any other in terms of their ability to learn the maze, This is a problem as it suggests learning is too complex to be localised and requires the involvement of the whole brain.

Question 11

Hemispheric lateralisation.

Answer 11

This refers to the fact that the two hemispheres of the brain are functionally different and that certain mental processes and behaviours are controlled by one hemisphere rather than the other.
For example language restricted to the left:
Split brain research can be used to investigate lateralisation.

Question 12

Split brain research. Who, surgery and procedure.

Answer 12

SPERRY - unique group of participants who had undergone surgical treatment for their schizophrenia (cutting their corpus collosum and other tissues that connect the two hemispheres.
His procedure involved asking the split brain patients to focus on a dot in the centre of the screen whilst projecting an image or word to each patients right visual field (processed by the left visual cortex) or left visual field ( processed by the right hemisphere followed by a task.

Question 13

Key findings from split brain research.

Answer 13

When the object was shows to the patients right visual field they had no problem describing the object but if it was shown to left visual field they could not say as it will be processed in the right cortex and language is restricted to the left cortex and no cross hemispheric communication can occur so will be unable to describe it.

Recognition by touch: participants were able to select a matching object from behind screen using their left hand when a word was presented to their left visual field (both tasks can be coordinated in right hemisphere) but participants would still not be able to verbally identify what they had seen but they could understand what the object was using their right hemisphere

Composite words

Question 14

Split brain research is

Answer 14

Well controlled -EV such as their head position- higher internal validity

Question 15

Split brain evidence was flawed

Answer 15

Small sample - 11 people low generalisability
Received different drugs for different amount of time
And control group had no history of epilepsy (poorly matched control)

Question 16

A problem is lateralisation

Answer 16

May be complicated by age
Lateralisation of function may change throughout an individuals life-time it was found that language became more lateralised to the left as children developed through adolescence this suggests It is much more complex process.

Question 17

Evidence from case studies have found that language may not be restricted to the left hemisphere

Answer 17

JW developed the ability to speak out of the right hemisphere and can speak about info presented to either the left or right brain. This is a problem as it disconfirms the conclusion that the right hemisphere cannot handle language.

Question 18

The brain

Answer 18

Centre of all conscious awareness, the brains outer layer is the cerebral cortex and it is divided into two hemispheres

Question 19

Spinal cord

Answer 19

Responsible for relaying information from the brain to the rest of the body.

Question 21

Brain plasticity

Answer 21

Ability of the brain to change, adapt and develop as a result of trauma learning and new experience. It was found that there was twice as many synaptic connections in at 2-3 year old than in an adult brain. As rarely used connections are deleted and frequent used connections are strengthened - synaptic pruning.
This plasticity is not restricted to a critical period and can occur at any stage of life - 60 year olds who were taught to juggle showed increase in grey matter in the visual cortex which then stopped and reversed when practising stopped.

Question 22

Functional recovery of the brain after trauma.

Answer 22

Unaffected areas of the brain are able to adapt and compensate for the function of those areas that are damaged - neural plasticity this recovery is spontaneously and occurs quickly after trauma but may stop after several weeks and require rehabilitate therapy for further recovery.
Brain can also rewire itself by forming new synaptic connections close to damaged area these are called secondary neural pathways are unmasked and activated to enable normal functioning

Question 23

What are the other structural changes in the brain.

Answer 23

Axonal sprouting - this is the growth of nerve endings which connect to other nerve cells to form new pathways.
Reformation of blood vessels
Recruitment of similar areas on the opposite side of the brain

Question 24

A03 for plasticity and functional recovery of the brain.

Answer 24

Support for plasticity comes from human research, an MRI scanner was used to scan the brains of London taxi drivers and they found a significantly more volume of grey matter in posterior hippocampus than a matched control group and the volume of the area was significantly correlated with the amount of time they had spent being a taxi driver this is positive as it shows the brain can adapt to learning and experience.

Question 25

Plasticity has practical application for brain trauma victims

Answer 25

This has led to developments in neuro-rehabilitation including movement therapy and electrical stimulation of the brain to counter the defecits in functioning. This is positive as although the brain may have the capacity to "fix" itself to a point the process requires further intervention for complete recovery.

Question 26

Plasticity can have negative consequences as

Answer 26

60-80% of amputees have been known to develop phantom limb syndrome- these sensations are usually unpleasant and painful this ‘negative plasticity is a problem as it shows that the brains ability to adapt to changes does not always have positive effects.

Question 27

Evidence for to support plasticity comes from animal studies

Answer 27

Rate places in more complex environments had increased number of new neurones than rats housed in simple laboratory cages the increased neurones of rats in complex environments were found in the hippocampus this is positive as it shows the human brain can adapt as a result of experience.

Question 28

FMRI

Answer 28

Measures changes in blood flow and oxygenation - haemodynamic response and activation maps (3D) P: records specific brain activity and can pinpoint specific responses supporting localisation of function - can show activity in deeper regions N: low temporal resolution, no real time recording of brain activity. - ignores networked structure of the brain.

Question 29

EEG

Answer 29

Electrical impulses via electrodes on scalp of individual through skull cap, shows brain wave patterns (action of millions of neurons) clinicians may use for diagnosis P: high temporal resolution as it provides a real time recording of brain activity. - takes into account networked structure of the brain the brain as a whole and how areas work together N: cannot see into deeper regions of the brain -only shows specific brain activity and cannot pinpoint specific responses.

Question 30

ERP

Answer 30

Using a statistical averaging technique extraneous brain activity from the original EEG recording can be filtered out ily leaving event related potentials: types of brain waves that relate to a specific function e.g. presentation of specific stimulus. P: records specific responses to specific stimuli this helps us with understanding brain functioning - also has high temporal resolution N: cannot see into deeper regions of the brain like other techniques can limits understanding. - lack of standardisation between researchers over the way data is statistically analysed.

Question 31

Post Mortem

Answer 31

Analysis of a persons brain following their death most likely those with a rare disorder or have experienced unusual behaviour in their lifetime. Areas of damage in the brain are examined as a mean of establishing the likely cause of affliction the person suffered this involves comparison with a neurotypical brain. P: allows us to see into deeper regions of the brain Was a vital foundation for the early understanding of the brain. N: raises ethical issue such as consent which cannot be given Technique is retrospective as the person is dead so researchers cannot follow up on anything that arises from examination

Question 32

Biological rhythm

Answer 32

Cycles in biological or psychological activity that occur over a certain amount of time, there are three different biological rhythms.

Question 33

Circadian

Answer 33

A cycle that occurs once a day -e.g. sleep wake cycle and growth hormone.

Question 34

Infradian

Answer 34

A cycle that occurs less than once a day such as the menstrual cycle and hibernation.

Question 35

Ultradian

Answer 35

Occur more than once a day - sleep wake cycle and digestion

Question 36

What are the mechanisms behind biological rhythms.

Answer 36

Endogenous pacemakers - internal biological clocks, that allow organisms to control internal rhythms they say a natural free running rhythm. Suprachiasmatic nucleus - main endogenous pacemaker in the body- tiny cluster of neurons in the hypothalamus implicated in maintaining bodily rhythms such as responding to light level (an external cue) to keep the cycle in rhythm. Exogenous zeitgeber these are external time givers (any external cue) that entrain our biological rhythms.

Question 37

The role of Endogenous Pacemakers and exogenous zeitgebers in the control of circadian rhythms.

Answer 37

Circadian rhythms- a cycle in biological or physiological activity that occurs once every 24 hours e.g. sleep wake cycle which occurs once a day and hormone production such as melatonin and growth hormone both peaking at midnight where’s cortisol is at its lowest. The main endogenous pacemaker (biological) in circadian rhythms is the suprachiasmatic nucleus a tiny cluster of neurons in the brain. SCN causes pineal gland to secrete melatonin which makes us feel sleepy. Circadian rhythms such as sleep wake cycle and are influenced by exogenous zeitgebers such as light or temp. SCN can respond to light however even without light SCN still the rise and fall of serotonin.

Question 38

A03 for circadian.

Answer 38

Evidence for support the idea that the SCN is the main endogenous pacemaker in sleep wake cycle comes from Morgan. When SCN is removed is hamsters and then their circadian rhythms will disappear completely and there circadian rhythms come back when a SCN from foetal hamster is put back into hamster this is important as it shows a relationship between the SCN and the maintenance of curcadian rhythms. However if a SCN of a mutant strain of hamster with a shorter cycle of 20 hours it will adopt the same activity patterns as the mutant. This shows that the circadian rhythm is inbuilt into the SCN. A huge strength of bodily rhythms is that they have practical applications for employers can use research to organise shift working patterns to increase worker productivity to create an efficient work force thus suggests that workers lives in the economy can be benefitted. Human evidence supports the roles of different factors controlling circadian rhythms. Siffre lived underground for 6 months with no cues from the sun about the time of day (no exogenous zeitgebers) his sleep wake cycle shifted to a pattern of 25 hours. This suggests endogenous pacemakers are important in controlling sleep wake cycle as he has a roughly daily cycle despite absence of exogenous zeitgebers. However it suggests exogenous zeitgebers such as light are important to entrain our body to stay in synchrony with the outside world 24 hours not 25.

Question 39

The role of endogenous pacemakers and exogenous zeitgebers in the control of infradian rhythms

Answer 39

Infradian is a cycle in biological or psychological activity that occurs less than once every 24 hours e.g human menstrual cycle (about every 28 days) and seasonal affective disorder which is a form of seasonal depression. Many Infradian rhythms are controlled by endogenously e.g. the menstrual cycle is controlled by the pituitary gland that releases hormones to control ovulation. Infradian rhythms are also controlled by exogenous zeitgebers such as light which plays a key role is SAD. Biochemicals such as pheromones can influence those nearby.

Question 40

A03 for Infradian

Answer 40

It can be argued that this is a nomothetic approach as it makes generalisations across all people and ignores individual differences. E.g. the menstrual cycle is shown to vary greatly. This is a problem as it does explain individual differences and may be more valid if an ideographic approach. A big strength is that it has practical applications as an increased understanding of SAD has enabled researchers to develop light therapy to reset the SCN. This is positive as it suggests that ongoing research into bodily rhythms can help benefit people’s lives. Evidence to support this comes from Russell. Samples of sweat from one group of women by applying bands underneath arms and this was applied to the upper lip of the second group menstrual cycles synchronised with donor positive as it shows pheromones act as exogenous zeitgebers.

Question 41

The role of endogenous pacemakers and exogenous zeitgebers in ultradian rhythms

Answer 41

More then once every 24 hours Main example is the stages of sleep that we go through in cycles lasting about roughly 90 mins each stage is characterised by different brain wave activity using EEG Stages 1 + 2: light sleep easily woken becomes more rhythmic (alpha waves) slowly becoming Theta waves Stages 3+4: delta waves (deep sleep) slowly becoming wave sleep difficult to rouse someone. Stage 5 REM sleep, body is paralysed but brain activity is high and is correlated with the experience of dreaming As all humans display similar trends suggests that rhyme is controlled by endogenous pacemaker.

Question 42

A03 for ultradian

Answer 42

Evidence to support the sleep wake cycle is controlled endogenously come from dement who found REM activity occurred on average every 92 minutes and by waking up participants during REM sleep found that they were more likely to be dreaming this is positive as it supports the timings of the sleep wake cycle Evidence to support the role of external factors in the sleep wake cycle comes from research into alcohol drugs and sleep they found that although alcohol may accelerate sleep onset and may send us into a deep sleep it also leads to a more fragmented cycle this is positive as it suggests that the ultradian rhythms of sleep stages can be changed due to external factors.