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More Sample
FMRI Data Time Series
¥ Second:
Event-related FMRI
H ÒActivationÓ occurs in single relatively brief intervals
H ÒEventsÓ
can be randomly or regularly spaced in time
o If events are randomly
spaced in time, signal model itself looks
noise-like (to the human eye)
H BOLD
response to stimulus tends to be weaker since
fewer nearby-in-time ÒactivationsÓ have overlapping
hemodynamic responses
¥ Next slide:
Visual stimulation experiment
ÒActiveÓ voxel
shown in next slide
