A2 biopsychology

Question 1

What did Franz Gall (1758 - 1828) find?

Answer 1

Founded phrenology in 1796; divided brain into 27 theoretical organs, of which 19 we share with other animals. Suggested they could be felt as bumps on the skull

Question 2

What did Flourens (1795 - 1867) discover?

Answer 2

Animal lesion (cutting up) studies on cerebellum and medulla oblongata, usually in rabbits and pigeons.

Question 3

What is meant by localised functions?

Answer 3

• in very simple organisms, the nervous system is not functionally divided.
• more complex organisms have evolved specialised nerves, and connections for important tasks
• functions are associated with activity specific areas of the brain. This is called localisation of function.
• complex behaviours are often associated with whole net works of these areas work together

Question 4

What is the function of the motor cortex?

Answer 4

stimulates and controls conscious physical movements

Question 5

What is the function of the somatosensory cortex?

Answer 5

synthesises info from from peripheral neurons to create physical sensation

Question 6

What is the function of the visual cortex?

Answer 6

receives, orients, groups and passes on visual signals from retina, through the optic nerve giving us visual perception (sight)

Question 7

What is the function of the auditory cortex?

Answer 7

Receives signals from the ears, through the CN-VIII nerve giving us auditory perception (hearing)

Question 8

What is the function of Broca’s area?

Answer 8

language production. Combines essential signals from other regions to create speech.

Question 9

What is the function of Wernicke’s area?

Answer 9

Centre for understanding language - allows us to interpret physical and verbal communication.

Question 10

What is the difference between Wernicke’s aphasia and Broca’s aphasia?

Answer 10

Wernicke- loss of ability to understand language

Broca- loss of ability to produce language.

Question 11

Evaluate the localisation of funtions theory.

Answer 11

The claim that functions are localised to certain areas of the brain has been criticised. Lashley proposed the equipotentiality theory, which suggests that the basic motor and sensory functions are localised, but that higher mental functions are not. He claimed that intact areas of the cortex could take over responsibility for specific cognitive functions following brain injury. This therefore casts doubt on theories about the localisation of functions, suggesting that functions are not localised to just one region, as other regions can take over specific functions following brain injury. Reductionism

P - Case studies
E - Wernicke and broca aphasia
E - Dronkers et al. (2007) conducted an MRI scan on Tan’s brain, to try to confirm Broca’s findings. Although there was a lesion found in Broca’s area, they also found evidence to suggest other areas may have contributed to the failure in speech production.
L - other parts of the brain effect it

Finally, some psychologists argue that the idea of localisation fails to take into account individual differences. Herasty (1997) found that women have proportionally larger Broca’s and Wernicke’s areas than men, which can perhaps explain the greater ease of language use amongst women. This, however, suggests a level of beta bias in the theory: the differences between men and woman are ignored, and variations in the pattern of activation and the size of areas observed during various language activities are not considered. Ignore extraneous variables

Question 12

define plasticity

Answer 12

ability to change and adapt in response to experience

• humans are born with small incomplete brains
• connections are made after new experiences- very quickly in children
• connections, used more grow thicker and develop more branches
• connections that are not used enough are destroyed
• plasticity can help us recover from injury

neuroplasticity decreases over time

Question 13

define structural plasticity

Answer 13

experience causes a change to brain structure

Question 14

define functional plasticity

Answer 14

localised functions move from a damaged region to an undamaged region after injury

Question 15

what are the stages in plasticity?

Answer 15

stage 1- synaptic pruning= axons that aren’t used will weaken and eventually are lost

stage 2- neural unmasking= a hormone nerve growth factor (NGF) encourages growth

stage 3- axonal sprouting= chemicals called neurotrophins sustain and encourage growth

stage 4- synaptic connection= new connections make its parent network stronger

Question 16

what are the stages of functional recovery?

Answer 16

1) axon damaged (axotomy)
2) axonal sprouting - new dendrite/axon growth towards target
3) blood vessel reform (capillaries and glial cells)- glial cells wrap around capillaries
4) recruitment of homologous (similar) areas- usually on the opposite hemisphere

Question 17

What are some reasons for plasticity?

Answer 17

• learning new skills
• developmental changes
• response to direct trauma/injury

Question 18

define functional recovery

Answer 18

functions performed by lost areas of brain are performed by undamaged areas of the brain.

Question 19

define denervation supersensitivity

Answer 19

to compensate for lost axons, the remaining axons become more sensitive. This can result in pain

Question 20

what is constraint induced therapy?

Answer 20

stopping patients from using coping strategies (e.g. body language) makes them improve via functional reorganisation

Question 21

what did Maguire et al (2000) find?

Answer 21

experiment: structural MRI brain scans of 16 male taxi drivers were compared to scans of 16 matched non taxi driver controls.
findings: the posterior hippocampi in London taxi drivers were found to be way larger than their controls. Size is positively correlated with the amount of time spent as a taxi driver.
conclusion: shows that the brain can adapt to psychological demands, in this case to improve memory

Question 22

What did Danelli et al (2013) find?

Answer 22

case study of 14 year old EB at the age of 2 and a half, EB had a hemispherectomy of the left side of his brain to remove a tumour. This removed the languages centres of Broca’s and Wernicke’s area

immediately after surgery EB had lost all language ability (aphasia). However after 2 years of recovery EB had recovered his language ability. Right hand side adapted (only had dyslexic symptoms)

Shows the brain can adapt.

Question 23

define hemispheric lateralisation?

Answer 23

Lateralisation is the idea that the 2 hemispheres function differently and are responsible for different things. The 2 sides are joined via the corpus callosum.

Question 24

What is contralateral organisation?

Answer 24

functional areas that are localised in both hemispheres will always connect to opposite sides of the body.

organised backwards

Question 25

How can slit brain patients tell us about lateralisation?

Answer 25

Some people had had accidents that affect a certain part of the brain. Some people can speak clearly and not understand a question and some the other way.

Question 26

What did Sperry (1968) discover?

Answer 26

aim: investigate hemispheric lateralisation of function in split brain patients.

Stimulus shown to either LHS or RHS and accuracy in reporting is recorded.

findings: stimuli presented to RHS can be reported verbally but not signed with right hand. Stimuli presented to LHS is the opposite.
conclusion: severing corpus callosum prevents lateralised functional areas from receiving signals from other side. Language is lateralised to left hemisphere.

Question 27

write 3 paragraphs evaluating lateralisation of the brain

Answer 27

P - It is assumed that the main advantage of brain lateralisation is that it increases neural processing capacity (the ability to perform multiple tasks simultaneously).
E - Rogers et al. (2004) found that in a domestic chicken, brain lateralisation is associated with an enhanced ability to perform two tasks simultaneously (finding food and being vigilant for predators).
E - Using only one hemisphere to engage in a task leaves the other hemisphere free to engage in other functions.
L - This provides evidence for the advantages of brain lateralisation and demonstrates how it can enhance brain efficiency in cognitive tasks. However this experiment was done on animals so cannot be generalised to humans

P - much of the research into lateralisation is flawed because the split-brain procedure is rarely carried out now, meaning patients are difficult to come by.
E - such studies often include very few participants, and sperry and Gazzinga’s research only included 11 patients, all of which had varying degrees of epilepsy
E - consequently, some psychologists have argued that Sperry’s research is really a collection of case studies that take an idiographic approach. Although an idiographic approach provides rich and interesting info in relation to individual cases, we are unable to create general laws or apply the results, as found in nomothetic research
L - any conclusions drawn are representative only of those individuals who had a confounding physical disorder that made the procedure necessary. This is problematic as such results cannot be generalised to the wider population.

P - Finally, it could be argued that language may not be restricted to the left hemisphere.
E - Turk et al. (2002) discovered a patient who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere, eventually leading to the ability to speak about the information presented to either side of the brain.
E - This suggests that perhaps lateralisation is not fixed and that the brain can adapt following damage to certain areas.
L - May be reductionist or the sample may have extraneous variables

Question 28

Write 3 evaluative paragraphs about plasticity and functional recovery.

Answer 28

There is further research to support the notion of brain plasticity. Maguire et al. found that the posterior hippocampal volume of London taxi drivers’ brains was positively correlated with their time as a taxi driver and that there were significant differences between the taxi drivers’ brains and those of controls. This shows that the brain can permanently change in response to frequent exposure to a particular task.
There is research to support the claim for functional recovery. Taijiri et al. (2013) found that stem cells provided to rats after brain trauma showed a clear development of neuron-like cells in the area of injury. This demonstrates the ability of the brain to create new connections using neurons manufactured by stem cells.
While there is evidence for functional recovery, it is possible that this ability can deteriorate with age. Elbert et al. concluded that the capacity for neural reorganisation is much greater in children than in adults, meaning that neural regeneration is less effective in older brains. This may explain why adults find change more demanding than do young people. Therefore, we must consider individual differences when assessing the likelihood of functional recovery in the brain after trauma.

A final strength of research examining plasticity and functional recovery is the application of the findings to the field of neurorehabilitation. Understanding the processes of plasticity and functional recovery led to the development of neurorehabilitation which uses motor therapy and electrical stimulation of the brain to counter the negative effects and deficits in motor and cognitive functions following accidents, injuries and/or strokes. This demonstrates the positive application of research in this area to help improve the cognitive functions of people suffering from injuries.

Question 29

write 3 evaluative paragraphs on studying the brain

Answer 29

P - an advantage of the EEG, in comparison to fMRI, is that it has good temporal resolution.
E - Temporal resolution refers to the accuracy of the scanner in relation to time: or how quickly the scanner can detect changes in brain activity. EEG scanners take readings every millisecond, meaning it can record the brain’s activity in real time as opposed to looking at a passive brain.
E - however fMRI scans have a temporal resolution of 1-4 seconds which is worse than other techniques (e.g. EEG)
L - this suggest that EEG can provide a high degree of accuracy when examining the onset of brain activity, allowing psychologist to make accurate conclusions in relation to the timing of neural activity, in comparison to fMRI.

P - However, one strength of fMRI in comparison to EEG, is that it has good spatial resolution.
E - spatial resolution refers to the smallest feature that a scanner can detect, and is an important feature of brain scanning. Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy. fMRI scans have a spatial resolution of approximately 1-2mm which is significantly better than other techniques.
E - EEG, on the other hand, can only detect activity in superficial regions of the brain
L - therefore, psychologists can determine the activity of different brain regions with greater accuracy with fMRI, in comparison to EEG, which makes fMRI an ideal choice when trying to pinpoint specific brain regions.

P - Finally one issue of both fMRI and EEG is the inability to show causation
E - fMRI scans do not provide a direct measure of neural activity. fMRI scans simply measure changes in blood flow and therefore it is impossible to infer causation (at a neural level)
E - likewise, the issue with EEG is that electrical activity is often detected in several regions of the brain simultaneously.
L - consequently, psychologists are unable to conclude whether particular brain regions are associated with specific functions (fMRI) and which area/region the electrical activity took place (EEG) making solid cause and effect conclusions impossible