Methods in cognitive neuroscience II Flashcards
what are three advantages of fMRI
safe and repeatable
high spatial resolution
moderate temporal resolution
what are four disadvantages of fMRI
expensive
not used with metal
aoustic noise
generate internal body heat
what is a problem with fMRI
succeptible to noise from heartbeat etc
what is donders subtration method
assumption of pure insertion
what does subtraction method assume
switching from one procedure to another may not merely insert or delete some processing stages; may also change the quality of other contaminant stages shared across different task
what is DTI
diffusion tensor imaging for determining anatomical connections vis axonal fibre tracts
what does EEG measure
electrical brain potentials
where does electrical brain activity come from?
positive and negative ions separation
how is information transmitted in the brain
by action potentials and postsynaptic potentials
what is temporal summation
when receive two potentials in succession leads to larger spike in acitivyr
what is spatial summation
from two neurons increasing activity
what are ERPs a reflection of
post synaptic dendritic potentials
compare post synaptic potentials with axonal action potentials
last longer and so are easier to record
what do ERPs represent
net electrical fields associated with activity of a sizable population of neurons- indiviual neurons must fire synchronously
what are the four reference points for EEG placement?
ionion
nasion
left and right preauricular points
what does ERP stand for
event related potentials
what are three things we find from ERPs
activity relating to beginning of event
brain stem responses
conceptual components
what are three measurable components of attentional memory
polarity
latency
topography
what are two considerations of ERPs
insufficient synchronous firing
geometric arrangement not open field (thalamus)
what are two advantages of EEG
excellent temporal resolution
cheap and non invasive
what is the disadvantage of EEG
poor spatial resolution
what causes poor spatial resolution in EEG
distance between source and electrodes
poor conductivity of some tissue
what is the inverse problem of EEG
we have result of activity but cannot find the source of that activity
what are the three techniques whihc produce high spatial resolution
pet
fmri
optical imaging
