ways of studying the brain- biopsychology Flashcards
what is functional megnetic reonance imaging
works by detecing changes in both blood oxygenation and flow that occur as result of neural acitivty in specific parts of brain
when brain area more active consumes more oxygen and to meet increased demand blood flow directed to active area known as haemodynamic response
fmri produces three dimensional images showing which parts of brain involved in particular metnal processes and this has important implications for understanding of localisation of function
what is electroencephalogram
measures electrical activity within brain via electrodes that are fixed to individuals scalp using skull cap
scan recording represents brainwave patterns generated from action thousands neurons providing overall account of brain activity
eeg often used clinicians as diagnostic tool as unusual arrhymthmic patterns of activity indicate neurological abnormalities such as epilepsy tumours or some sleep disorders
what is event related potentials
eeg many scientific and clincal applications in raw form it is crude and overly general measure of brain activity
within eeg data are contained all neural responses associated with specific sensory, cognitive and motoro events that may be of interest to cognitive neuroscientists
researchers developed way of testing out and isolating responses, using statistic averaging technique all extraneous brain activity from original eeg recording filtered out leaving only responses relate
what remains are event related potentials types of brainwaves that are triggered by particular events
research revealed many different forms of erp and how far these are linked to cognitive processes such as attention and perception
what is post modern examinations
technique involving analysis of persons brain following death
research individuals whose brain subject to post mortem examination liekly to be those who have rare disorder and ahve experienced unusual deficits in cognitive processes or behaviour during lifetime
areas of damage wthin brain examined after death as means of establishing the likely cause of affliction person experienced
may involve comparison with neurotypical brain in order to ascertain extent of difference
what is functional magnetic resonance iamging
strengths- fmri does not rely on use of radiation
administered correctly virtually risk free non invasive and straightforward to use
produces images that have high spatial resolution depciting detail by mm and providing clear picture of how brain activity is localised
fmri can safely provide clear picture of brain activity
weakness-expensive compared to others
poor temporal resoution because there is around 5 second time laf behind image on screen and initial firing of neuronal activity
fmri may not truly represent moment to moment brain activity
what is electroencephalogram
strengths- useful in studying stages of sleep and diagnosis of conditions such as epilepsy
extremely high temporal resoluton
accurately detect brain activity at resolution of single milisecond
shows real world usefulness of technique
weakness-generalised nature of information received
eeg signal not useful for pinpointing exact source of neural actiivty
does not allow researchers to distinguish between activities oringating in different but adjacent locations
what is event related potentials
limitations eeg partly addressed through use of erps- bring more specificity to measurement of neural processes than could be achieved using raw eeg data
erps derived from eeg measurements good temporal reslution when compared to neurimaging techniques such as fmri
erps used to measure cognitive functions and deficits such as allocation of attentional resources and maintenance of working memory
lack of standardisation in erp methodolog between different research studies
makes it difficult to conffirm findings
in order establish pure data in erp studies background noise and extraneous material must be eliminated
may not always be easy to achieve
what is post mortem examinations
vital in providing foundation for early understanding of key processes in brain
broca and wernicke relied on post mortem studies in estblishing linkns between lang brain and behaviour decades before neuroimaging
used to study HMs brain idetify areas of amage which could then be associated with his memory deficits
continue to provide useful info
causation issue
observed damage to brain may not be linked to deficits under review bt to some other unrelated trauma or decay
post mortem stuies raise ethical issues of consent from idnivdual before death
pps may not be able to provide informed consent- HM lost ability to form memories and was not able to provide consent but been conducted on study
challenges usefulness of post mortem studies
