biopsychology : split brain research and ways of studying the brain Flashcards
spit brain research
what is meant by hemispheric brain lateralisation?
when 2 different hemispheres are specialised to have different functions and some mental processes are controlled by one hemisphere
spit brain research
what function is the left hemisphere specialised for?
language, computation, logical reasoning
spit brain research
what function is the right hemisphere specialised for?
spatial reasoning, face recognition, music
spit brain research
describe the procedure Sperry used to research split brain patients: how was information presented to make sure it was only processed by one hemisphere?
prodecure:
- 11 patients who had corpus callosum cut (separate hemispheres)
- patients given a fixation point to look at on one screen and image/word presented to left visual field or right visual field (eye)
- information could not be transferred by one hemisphere to another and therefore you can see the function of each hemisphere in isolation
spit brain research
what were the responses of the split brain patients if word presented to RVF or LVF
RVF= say it, not write it
LVF= draw it, not say it
spit brain research
what were the responses of the split brain patients if image presented to RVF or LVF
RVF= describe, not draw
LVF= draw, not describe
spit brain research
ao3: why are there issues of generalisation from split brain research
because it is questioned wether the results can be generalised to ‘normal’ brains
spit brain research
ao3: why was Sperrys research important
he showed the brain has lateralised functions, and that the right hemisphere can produce basic words and phrases and contributes to emotional and holistic content in language, and the left hemisphere is more geared towards analytic and verbal tasks
spit brain research
ao3: what has happened to the differences between the 2 hemispheres
they have been exaggerated- not as different in ‘normal’ brains than split brains
ways of investigating the brain
what is fMRI used to measure? give an example
used to measure brain activity while a person is preforming a particular task
ways of investigating the brain
how does an FMRI work?
measures changes in blood oxygen levels as a result as neurological activity in the brain
higher oxygen levels mean those areas are more active
also detects radio waves from changing magnetic fields- live and shows what’s happening in brain
ways of investigating the brain
ao3: why is it a strength that fMRI have high spatial resolution
it can locate the precise area in the brain where the function is taking place
ways of investigating the brain
ao3: why is it a limitation that fMRI has poor temporal resolution
there is a time delay (around 5 seconds) between the brain preforming the function and the image produced
ways of investigating the brain
what is EEG used to measure?
electrical activity in the brain via electrodes fixed to a persons scalp using a skull cap
ways of investigating the brain
how does EEG work?
it produces a record of the tiny impulses produced by the brains activity, the scan recording represents the brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity.
ways of investigating the brain
what disorders/processes has EEG help us understand
EEG is often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity (i.e. no particular rhythm) may indicate neurological abnormalities such as epilepsy, tumours or disorders of
ways of investigating the brain
ao3: EEG showed generalised activity throughout the brain- why is this a limitation
it isn’t useful for pinpointing the exact source of neurological activity and does not allow researchers to distinguish between activities originating in different but adjacent locations
ways of investigating the brain
what are ERPS used to measure?
neural activity related to both sensory and cognitive processes
ways of investigating the brain
how do ERPs work?
use electrodes that are attached to the scalp like an EEG, however stimulus is presented to a participant and researcher looks for activity related to that stimulus and uses statistical analysis filter to filter out background neural activity- records very small changes in brain triggered by stimuli
ways of investigating the brain
give a strength of ERPS over using EEGs alone
data is derived from raw EEGs in superficial areas of the brain where activity is detected and have better temporal resolution , addresses the limitations of EEGs
ways of investigating the brain
what are brain post morgen examinations used to measure?
analyses a persons brain following their death, individuals whose brains are subject to post-mortem are likely to be those who have a rare disorder, areas of damage within the brain are examined after death to establish likely cause of the harm the person experienced
ways of investigating the brain
ao3: why is causation an issue with post morgen studies?
observed damage to the brain may not be linked to the defeicts under review but to some other unrelated trauma or decay
ways of investigating the brain
ao3: what is the key advantage of post mortem studies compared to other ways of investigating the brain
post-mortem evidence was vital in providing a foundation for early understanding of key processes in the brain, Broca and Wernicke both relied on post-mortem studies in establishing links between language, brain and behaviour decades before other ways of investigation were introduced. they improved medical knowledge and helped generate hypotheses for further study.
