ways of studying the brain Flashcards
functional magnetic resonance imaging (FMRI) description
detects changes in blood oxygenation and flow that occurs due to neural activity in the brain
if the brain is more active = increased demand for oxygen
FMRI produces 3D image showing activity in active area
high flow = high brain activity
electroencephalogram (EEG) description
measures electrical activity within the brain via electrodes using a skull cap
scan shows brain wave patterns generated from neurons
data is used to detect brain disorders
event-related potentials (ERPs) description
ERPs are whats left when all extraneous brain activity from an EEG recording is filtered out
electrodes are attached to scalp
stimulus presented to participant to look for activity - presented multiple times and average response is graphed - reduces extraneous neural activity
time between stimulus and response is called latency
if waves occur 100 millisecs after stimulus = sensory
anything after = cognitive
post-mortem examinations
involves analysis of persons brain after death
areas examined to establish the likely cause of deficit/ disorder
FMRI strength - risk free
p - risk free because it doesn’t rely on radiation
e - produces images with high spatial resolution showing detail to the mm
e - means that FMRI can safely provide a clear picture of how brain activity is localised
FMRI weakness - expensive and poor temporal resolution
e - poor resolution because of the 5 sec lag between initial neural activity and image
e - means FMRI may not truly represent moment-to-moment brain activity
EEG strength - high temporal resolution
p - practical use and high temporal resolution
e - has contributed to our understanding of sleep stages. high resolution = brain activity in 1 millisecond
e - shows real world use
EEG weakness - information is generalised and source is not pinpointed
e - produces a generalised signal from thousands of neurons - difficult to know the exact source of neural activity
e - can’t distinguish activity of different but adjacent neurons
ERPs strength - specificity snd good temporal resolution
e - measures of neural processes is more specific that EEGs - better resolution than FMRI
e - means ERPs are frequently used in cognitive research
ERPs weakness - lack of standardisation and background noise
e - no standardisation = difficult to confirm findings in studies involving ERPs. background noise and extraneou material must be eliminated
e - these issues are a problem as they aren’t always easy to achieve
post mortem strength - localisation and medical research
e - Broca and Wernicke’s areas both relied in post mortem
e - they continue to provide useful information
post mortem weakness - knowing causation and ethics
e - observed damage may not be linked to the deficits under review. raise ethical issues of consent after death
e - challenges their usefulness in psychological research
