I'm having trouble understanding how to set up the design matrix for the
following project.
Each subject is prsented with an instruction, 'word' or 'colour' followed by
the post instructions period then the stimulus is presented during scan 6 and
the response(button press) occurs. Scans 1-5 are the instruction-related scans,
scans 6-10 the response-related scans. The stimulus is congruent (eg RED in red)
or incongruent( RED in purple). We have 480 scans, 48 trials therefore 10
scans/trial. I have set 4conditons, word, colour, congruent, and incongruent.
Word or Colour is presented 24 times in random order and stimulus presentation
congruent or Incongruent, presented 24 times in random order. Am I correct to
do the following:
TR 2.5
480 scans
conditions 4
Stochastic Design NO
SOA Variable
variable durations NO
parametric modulation NONE
EVENTS
Basis Set HRF(alone)
interaction among trials NO
regressors 0
Any help or comments would be absolutely great.
thanks so much in advance,
Maria
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