¥ Second: Event-related FMRI
H ÒActivationÓ occurs in single relatively
brief intervals
H ÒEventsÓ can be randomly or regularly
spaced in time
² If events are randomly spaced in time,
signal model itself looks
noise-like
H BOLD response to stimulus tends to be
weaker since fewer nearby-in-time
ÒactivationsÓ have overlapping hemodynamic
responses
¥Next slide: Visual
stimulation experiment