Dear Dave,
I was doing a stroop vocal recorded experiment. I add all stimuli in one formal block. Since one block has 12 trials and four color words are divided into congruent and incongruent conditions (as well a neutral condition), I put these three conditons into one block, and wrote the script like this:
" trials = [1-144 =
noreplace (con1.BMP, con2.BMP, con3.BMP, con4.BMP, con1.BMP, con2.BMP, con3.BMP, con4.BMP, incon1.BMP, incon2.BMP,incon3.BMP, incon4.BMP, incon5.BMP, incon6.BMP, incon7.BMP, incon8.BMP, incon9.BMP,incon10.BMP, incon11.BMP, incon12.BMP, n1.BMP, n2..BMP, n3..BMP, n4.BMP,n1.BMP, n2..BMP, n3..BMP, n4.BMP,n1.BMP, n2..BMP, n3..BMP, n4.BMP....)]"
('con' stands for congruent condition, 'incon' stands for incongruent condition, 'n' stands for neutral condition)
This would help me to make sure that trials are set according to my expectation, with neutral and congruent trials appearing for three times each, while each incongruent trial appearing for only once. But this couldn't guarentee that the stimulusitem also being presented according to this rule, since the trialcode and stimulusitem are unrelated.
So my confusion is how can I make sure the stimulusitem are presented according to the rule above?
One more question, how can I present the stimulusitem randomly between blocks (not within each block)?
Thanks so much for any of your help!
Yours,
Lulu