¥Goal: to design an effective
random stimulus presentation
_end result will be stimulus timing files
_example: using an event related design, with simple
regression to analyze
¥Steps:
_0. given:
experimental parameters (stimuli, # presentations, # TRs, etc.)
_1. create
random stimulus functions (one for each stimulus type)
_2. create
ideal reference functions (for each stimulus type)
_3. evaluate
the stimulus timing design
¥Step 0: the (made-up)
parameters from HowTo 03 are:
_ 3 stimulus
types (the classic experiment: "houses, faces and donuts")
_presentation order is randomized
_TR = 1 sec, total number of TRs = 300
_number of presentations for each stimulus type = 50
(leaving 150 for fixation)
"fixation time should be 30% ~ 50% total scanning
time
_3 contrasts of interest: each pair-wise comparison
_refer to directory: AFNI_data1/ht03