plasticity, functional recovery of the brain after trauma, split brain research into hemispheric lateralisation, ways of investigating the brain

Question 1

what is plasticity also referred to as?

Answer 1

neuroplasticity or cortical remapping

Question 2

what is plasticity?

Answer 2

the brains tendency to change and adapt both functionally and physically as a result of experience and new learning

Question 3

what happens to rarely used and frequently used connections as we age?

Answer 3

rarely used connections are deleted

frequently used connections are strengthened

Question 4

what is the strengthening and deleting of connections process called?

Answer 4

synaptic pruning

Question 5

what happens during infancy according to Gopnick et al.?

Answer 5

the brain experiences a growth in the number of synaptic connections, peaking at approximately 15,00 at age 2-3

Question 6

can existing neural connections change, and new neural connections form at any time in life due to experience and learning?

Answer 6

yes

Question 7

who studied the brains of London taxi drivers?

Answer 7

Maguire et al

Question 8

what did Maguire et al. find?

Answer 8

London taxi drivers had significantly more volume of grey matter in the posterior hippocampus than in a matched control group

Question 9

what is the posterior hippocampus associated with?

Answer 9

the development of spatial and navigational skills in humans and other animals

Question 10

what is the learning experience that seems to alter London taxi driver’s brains?

Answer 10

‘the knowledge’- assesses their recall of the city streets and possible routes

Question 11

what was the positive correlation that Maguire et al. find?

Answer 11

the longer the taxi drivers had been in the job, the more pronounced the structural difference was

Question 12

who else found similar findings to Maguire et al’s. study? (2 people)

Answer 12

Draganski et al

Mechelli et al

Question 13

what is functional recovery? is it a form of plasticity?

Answer 13

following damage through trauma, the brains ability to redistribute or transfer functions usually performed by a damaged area(s) to other, undamaged area(s)
yes

Question 14

what do neuroscientists suggest in terms of how quickly functional recovery happens?

Answer 14

the process of functional recovery can occur quickly after trauma (spontaneous recovery), and then slow down after several weeks or months

Question 15

how does the brain recover?

Answer 15

it rewires and reorganise itself by forming new synaptic connections close to the area of damage

Question 16

what do secondary neural pathways that aren’t typically used to carry out certain functions do in functional recovery according to Doidge?

Answer 16

they are activated/’unmasked’ to enable functioning to continue

Question 17

what are 3 structural changes in the brain that support Doidge’s ideas?

Answer 17

axonal sprouting
reformation of blood cells
recruitment of homolongous (similar) areas

Question 18

what is axonal sprouting?

Answer 18

the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

Question 19

what does recruitment of homolongous (similar) areas mean?

Answer 19

homolongous (similar) areas on the opposite side of the brain are recruited to perform specific tasks. after a period of time, functionality may then shift back to its original side

Question 20

what field has plasticity contributed to?

Answer 20

neurorehabilitation

Question 21

what does neurorehabilitation show regarding plasticity and functional recovery?

Answer 21

although the brain has the capacity to ‘fix’ itself to a point, it requires further intervention if it is to be completely successful

Question 22

does plasticity have practical applications?

Answer 22

yes

Question 23

can the brains ability to rewire itself sometimes have maladaptive behavioral (negative) consequences?

Answer 23

yes

Question 24

does functional plasticity tend to reduce or increase with age?

Answer 24

reduce

Question 25

who showed that neural plasticity continues throughout the lifespan in a study using golfers?

Answer 25

Bezzola et al

Question 26

what did Hubel and Wiesel find in their early study on neuroplasticity and functional recovery using kittens and what was their procedure?

Answer 26

they sewed one eye of a kitten shut and analysed the brains cortical responses. the area of the visual cortex associated with the shut eye was not idle, but continued to process information from the open eye

Question 27

does evidence suggest that a persons educational attainment may influence how well the brain functionally adapts after injury (the more education- the greater the chances of a disability free recovery (DFR))?

Answer 27

yes

Question 28

what is hemispheric lateralisation?

Answer 28

the idea that the 2 halves (hemispheres) of the brain are functionally different and that certain mental processes and behaviors are mainly controlled by one hemisphere rather than the other

Question 29

how was hemispheric lateralisation investigated?

Answer 29

using split brain studies

Question 30

who were the participants in the split brain research?

Answer 30

epileptics who had experienced a surgical separation of the hemispheres in the brain

Question 31

who conducted the split brain studies?

Answer 31

Sperry

Question 32

why did Sperry conduct studies on split brains?

Answer 32

to see the extent to which the 2 hemispheres were specialised for certain functions, and whether the hemispheres performed tasks independently of one another

Question 33

what procedure did Sperry use?

Answer 33

a general procedure in which and image or word could be projected to a patients right visual field (processed by the left hemisphere) and the same or different image or word could be projected to the left visual field (processed by the right hemisphere)

Question 34

why did Sperry use this procedure on split brain patients?

Answer 34

in the ‘normal’ brain, the corpus callosum would immediately share the information between both hemispheres, giving a complete picture of the visual world. however, presenting the image to one hemisphere of a split brain patient meant that the information could not be conveyed from one hemisphere to the other

Question 35

what were the findings of Sperry’s study when patients were asked to describe what they could see?

Answer 35

when a picture of an object was shown to a patients right visual field, the patient could easily describe what they saw. if, however, the same object was shown to the left visual field, the patient could not describe what was seen, and typically reported that there was nothing there. this is because language is processed in the left hemisphere, and not the right, meaning they weren’t able to describe what they saw in their left visual field

Question 36

what were the findings of Sperry’s study when patients had to recognise an object by touch?

Answer 36

when an object were placed in the right hand (processed by the left hemisphere), the patients could verbally describe what they felt, and could identify the test object by by selecting a similar object. when an object was placed in the left hand (processed by the right hemisphere), however, the patient could not describe what they felt and could only make wild guesses. they could identify the test object by selecting a similar object

Question 37

what were the findings of Sperry’s study when patients were asked to draw what they saw?

Answer 37

when a picture was presented to the right visual field (processed by the left hemisphere), the right hand would attempt to draw the picture but it never came out as clear as the left hand, which shows that the right hemisphere is superior in processing visual motor tasks. the left hand was able to draw a considerably clearer image of the picture, even though all the participants were right handed

Question 38

what does the split brain research suggest about hemispheric lateralisation?

Answer 38

the left hemisphere is the analyser (analysing, verbal tasks)
the right hemisphere is the synthesiser (spatial tasks, music, contributes emotional and holistic content to language)

Question 39

was Sperry’s procedure strong or weak? why?

Answer 39

stong

it was a highly specialised and standardised procedure

Question 40

did Sperry’s work prompt a theoretical and philosophical debate about the degree of communication between the 2 hemispheres?

Answer 40

yes

Question 41

what did Pucetti suggest?

Answer 41

the 2 hemispheres are so functionally different that it represents a form of duality in the brain- we are all 2 minds

Question 42

what do other researchers argue (against Pucetti’s idea)?

Answer 42

the 2 hemispheres form a highly integrated system and are both involved in most everyday tasks

Question 43

are there issues with generalisation in Sperry’s research? why?

Answer 43

yes

unusual participants- split brain epileptics only make up a tiny percentage of the population

Question 44

how do functional magnetic resonance imaging (fMRI)’s work?

Answer 44

it detects the changes in blood oxygenation and flow that occur as a result of neural (brain) activity in specific parts of the brain. when a brain area is more active it consumes more oxygen and to meet this increased demand blood flow is directed to the active area

Question 45

what are electroencephalograms (EEG’s)?

Answer 45

a record of the tiny electrical impulses produced by the brains activity. by measuring characteristic wave patterns, the EEG can help diagnose certain conditions of the brain

Question 46

what are event-related potentials (ERP’s)?

Answer 46

the brains electrophysiological response to a specific sensory, cognitive, or motor event can be isolated through statistical analysis of EEG data

Question 47

what are post-mortem examinations?

Answer 47

when the brain is analysed after death to determine whether certain observed behaviors during the patients lifetime can be linked to abnormalities in the brain

Question 48

what are the strengths of fMRIs?

Answer 48

it does not rely on the use of radiation
risk free
non-invasive
straightforward
images are clear, and can easily see how brain activity is localised

Question 49

what are the weaknesses of fMRIs?

Answer 49

expensive

poor temporal resolution- 5 second lag

Question 50

what are the strengths of EEGs?

Answer 50

able to diagnose conditions e.g. epilepsy
helped our understanding of sleep stages
high temporal resolution

Question 51

what are the weaknesses of EEGs?

Answer 51

generalised nature of the information received

Question 52

what are the strengths of post mortem examinations?

Answer 52

provided a foundation for early understanding of key processes in the brain
improve medical knowledge
help generate hypotheses for further study

Question 53

what are the weaknesses of post mortems?

Answer 53

causation issues

ethical issues- unable to consent