brain organisation and function✅ Flashcards
define localisation of function
the idea that certain functions have specific areas within the brain
describe an A03 point of localisation of the brain regarding supporting cased studies
P- supporting evidence
E - Tan had stroke which damaged Brocas area –> couldn’t speak
E - demonstrates that when a localised area of brain is damaged there is impact on specific function
CP- case studies = idiographic so cant create nomothetic law –> less valid
describe the motor area of the brain
- responsable for planning and controlling fine voluntary movements eg: writing
- located in frontal lobe
describe the somatosensory area of the brain
- detects and processes sensory info that arises from different parts of body eg: taste
- located in parietal lobe
describe the visual cortex area of the brain
- processes visual info
- located in occipital lobe
describe the auditory cortex area of the brain
- processes auditory info
- located in temporal lobe
describe language lateralisation
- language is lateralised to the LEFT hemisphere
- if this center is damaged, right structure couldn’t ‘take over’
describe Broca’s area
- responsible for speech production
- located on the left side of the frontal lobe
what is an A03 point of Broca’s area
P - may not be limited to BA
E - Dronkers found evidence to suggest that other areas may have contributed to failure of speech production
- BA isn’t solely responsible
L - decreases validity of localisation
Describe Wernick’s area
- responsible for language comprehension
- located on the left side of the temporal lobe
what is the name used to descrive the condition people face when they have damage to wernick’s area?
Wernick’s aphasia
what is an A03 point of Wernick’s area
- Saygin et al. found some patients displayed symptoms of Wernick’s aphasia without any damage to this area
- language comprehension is more complex
in order for normal speech patterns to develop, what has to happen?
- two brain areas have to work together
- the arcuate fasciculus connects the two regions
what are some overall A03 point of localisation theories
- opposing evidence –> Lashley
- fails to take into account individual difference –> Herasty
what is an A03 point of localisation of function regarding Lashley’s opposing research
- Lashley claimed that not all cognitive functions were localised
- higher mental functions involved in learning arent
- equipotentiality theory = if some parts of brain is damaged others will take over
- damage nn brain determined by extent of damage not location
- decreases validity –> brain should be viewed hollistically
what is an A03 point of localisation of function regarding failing to take into account individual differences
- Herasty found women have proportionally larger brocas/wernicks area
- however - beta bias - men and women differences are ignored
- therefore creation of one universal theory may not be possible –> reduces validity of localisation theory
describe how Functional Magnetic Resonance Imaging (FMRI) works
- measures blood flow in the brain when a person performs a task
- energy requires glucose and oxygen
- oxygen is carried in bloodstream attached to haemoglobin and is released for use by active neurons, at which point haemoglobin becomes deoxygenised
- FMRI detects different magnetic qualities between oxyginated/deoxygenated haemoglobin and creates a dynamic 3D map of brain
- increase in bloodflow for oxygen = increase in neural activity
what are the results like of an FMRI
- shows activity approx. 1-4 seconds after occurrence
- accurate within 1-2 mm
what are some overall A03 points of FMRIs
- non invasive ✅
- expensive❌
- poor temporal validity ❌
describe an A03 point of FMRIs regarding being non-invasive
- risk free
- allows more patients to undertake the scan
- helps psychologists understand more about functioning human brain
CP –> must say still so not suitable for all eg: tourettes
describe an A03 point of FMRIs regarding expenses
- expensive to built/operate
- high maintenance cost, professional required
- sample sizes may be small due to limited availability of funding
- cost per participant = high
- lowers validity and makes it hard to generalisability
describe an A03 point of FMRIs regarding temporal resolution
- 5 second time lag behind image on screen and official firing of neuron activity
- lowers validy
describe how electroencephalograms (EEGs) work
- measure electrical activity through electrodes attached to scalp
-small electrical charges detected by electrodes are graphed over time, indicating the level of activity in brain
what are the 4 types of EEG patterns
- alpha waves
- beta waves
- theta waves
- delta waves
each pattern has two basic properties that can be examined :
- amplitude
- frequency
describe how Event Related Potentials (ERPs) work
- same as EEG yet stimuli are presented to participants (eg sound)
- average response is graphed
ERPs have very short latency divided into two categories:
- waves occurring withing 100ms following stimuli are sensory ERPs
- waves occurring after 100ms are cognitive ERPs
what are some overall A03 points of EEG/EEP
- less expensive than others ✅
- poor quality images❌
- good temporal resolution✅
describe an A03 point of EEG/ERPs regarding less expensive
- less expensive than other methods
- more widely available to researchers
- non invasive so accessible–> wider sample = more validity
describe an A03 point of EEG/ERPs regarding poor quality
- poor quality images due to poor spatial resolution
- cant provide accurate info about neural activities
- cant establish precise brain region activities associated with given task –> estimations only
describe an A03 point of EEG/ERPs regarding temporal resolution
- good temporal resolution
- takes readings every millisecond –> records brain activity in real time
- accurate measurement of electrical activity when undertaking a specific task
describe how post mortems work
- study physical brain of a person who displayed a particular behaviour when they were alive
- allows for a more detailed anatomical and neurochemical aspects of brain
- enable researchers to examine deeper regions of brain such as hypothalamus
give an example of a post mortem case study
HM –> hippocampus was removed due to stroke
what are some overall A03 points of post mortems
- allowed the brain to be deeper understood✅
- retrospective ❌
describe an A03 point of post mortems regarding deeper understanding
- we now have deeper understanding of abnormalities such schizophrenia
- post mortems have improved medical knowledge
- can generate hypotheses for further studies
describe an A03 point of post mortems regarding retrospectively
- limited as its retrospective as the person is already dead
- unable to follow up on anything that arises concerning relationships between brain abnormalities and cognitive functioning
what does brain plasticity refer to
the fact that the brain is able to adapt and change due to new experiences
what are some ways that the brain can create/alter neural pathways
- playing video games
- plasticity as a result of life experiences
describe how playing video games changes your brain
- Kuhn examined a group who played super Mario for 30 mins a day for 2 months
- found an increase in grey matter in areas such as cortex and cerebellum
- video games resulted in new synaptic connections in areas involved in spacial navigation and planning
describe how plasticity occurs as a result of life experiences
- Maguire studied brains of london taxi drivers and found they had more grey matter in hippocampus (memory)
- new experiences such as route planning creates new neural connections
what are the ways that functional recovery of the brain can occur
- neuronal unmasking
- stem cells
- axonal sprouting
- recruitment of homologous areas
describe how functional recovery of the brain can happen through neuronal unmasking
- if part of the brain become damaged, activity of surrounding neurones may increase
- this ‘unmasks’ these usually dormant neurons
- they revert from dormancy to active which allows connections between neurons to open up
describe how functional recovery of the brain can happen through stem cells
- its possible for stem cells implanted in the brain directly replace dying/dead cells
- can carry out different functions
describe how functional recovery of the brain can happen through axonal sprouting
- the growth of new nerve endings which connect with other undamaged nerve cells to form other neuronal pathways
describe how functional recovery of the brain can happen through the recruitment of homologous areas
- homologous area of the the brain on the opposite side is used to perform specific task
- after a period of time, functioning may shift back to original area
eg: is brocas area was damaged, right side equivalent would take over
what are some overall A03 points of plasticity and functional recovery research
- practical applications ✅
- research support - Taijiri✅
- may deteriorate with age ❌
describe an A03 point of plasticity and functional recovery research regarding practical applications
-increased understanding has contributed to Neurorehabilitation
–> includes use of motor therapy and electrical stimulation of brain to counter reduced brain functionality
- demonstrates that recovery is possible and Rehabilitation programmes have been successful
- adds validity + usefulness
describe an A03 point of plasticity and functional recovery research regarding research support
- Taijiri found that stem cells provided to rats after brain trauma showed clear development of neuron-like cells in injured area
- shows ability of brain to create new connections using neurons manufactured by stem cells
describe an A03 point of plasticity and functional recovery research regarding regarding deterioration with age
- Elbert colcluded that the capacity for neural reorganisation is greater in children than adults –> less effective in older brains
- may explain why old ppl find change more demanding
- must consider individual differences
define lateralisation
the idea that two halves of the human brain arent exactly alike
- each hemisphere has functional specialisations
give an example of lateralisation of language
- Broca found that damage to left hemisphere led to speech deficits
- left hemisphere is specialised for language based tasks
what enables communication between the two hemispheres of the brain?
corpus callosum
(bundle of fibres which connects two sides)
describe the aim of Sperry and Gazzaniga’s split brain research
to examine the extent to which the two hemispheres are specialised for certain functions
describe the method used in Sperry and Gazzaniga’s split brain research
- projected image/word to either patients left visual field (processed by right hemisphere) or right visual field (processed by left hemisphere)
- when info is presented to one hemisphere in a split brain patient, info is not transferred to other hemisphere
(corpus callosum is cut)
describe the different types of tests used by Sperry and Gazzaniga’s split brain research
- describe test –> picture was presented to either left or right visual field and pps had to describe it
- tactile test –>object was placed in pps left or right hand and they had to describe what they felt
- drawing –> pps were presented with a pic in either left or right VF + draw what they saw
describe the findings of the describe task regarding Sperr and Gazzaniga’s split brain research
picture presented to RIGHT visual field:
- patients could easily describe what they saw
- shows how dominant the left HS is in language production
picture presented to LEFT visual field:
- patient couldn’t describe object
describe the findings of the tactile task regarding Sperr and Gazzaniga’s split brain research
objects placed in RIGHT hand:
- patients could describe verbally what they felt
objects placed in LEFT hand:
- couldn’t describe verbally what they felt
describe the results of the drawing task regarding Sperr and Gazzaniga’s split brain research
picture presented to RIGHT visual field:
- right hand could attempt to draw but picture was never as clear as the left hand
- demonstrates superiority of the right hemisphere for visual motor tasks
picture presented to LEFT visual field:
- consistently draw clear pictures even tho pps were right handed
- demonstrates superiority of the right hemisphere for visual motor tasks
what is the left hemisphere dominant for
language/word processing
what is the right hemisphere dominant for
visual motor based tasks
what are some overall A03 points of brain lateralisation/split brain research
- may provide evidence for evolutionary benefits of lateralisation✅
- language may not be restricted to left hemisphere❌
- good methodology✅
describe an A03 point of brain lateralisation/split brain research regarding providing evidence for evolutionary benefits of lateralisation
- Rogers showed that brain lateralisation increases neural processing capacity
- in chickens, lateralisation is associated with enhancing ability to do 2 cognitive tasks at once (finding food and watching for predators)
- provides evidence for the advantaged of brain lateralisation
HWV research done on chickens –> cant confidently apply it to humans
describe an A03 point of brain lateralisation/split brain research regarding the argument that language may not be restricted to the left hemisphere
- Gazzaniga’s research has recently been discredited
- Patient known as J.W developed ability to speak out of the right hemisphere
- challenges idea that the right brain is unable handle language tasks
describe an A03 point of brain lateralisation/split brain research regarding methodology
- Gazzaniga’s experimental procedure is highly rigorous + standardised
- groundbreaking new way of investigating brain
- replicable = increased reliability
