Linearity
and Extended Activation
¥ Extended activation, as in a block-trial experiment:
H HRF accumulates over its duration (È
10 s)
H
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