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Linearity
and Extended Activation
¥ Extended
activation, as in a block-trial experiment:
H HRF
accumulates over its duration (È 10 s)
2
Extended Activations
¥ Black curve = response to a single brief stimulus
¥ Red curve = activation
intervals
¥ Green curve = summed
up HRFs from activations
¥ Block-trials have larger
BOLD signal changes than event-related experiments