„ Recall: -iresp
option outputs the HRF model for one stimulus
H When used with -stim_times, values are usually output using the dataset TR time
spacing
H Can changes to a different grid via new -TR_times dt option, which sets the
output grid spacing for -iresp
to dt for HRF models computed
via -stim_times
o Is useful
for producing nice smooth pictures of HRF
o Also works
with -sresp option (= std.dev.
of HRF)
„ Difficulty: using GLTs with results from -stim_times
H GLTs operate on regression
coefficients
H For most rtype models, regression coefficients donÕt correspond directly to HRF
amplitudes
o Exceptions:
GAM, TENT, BLOCK
o Planned solution: see next slide