„ 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