Task-switching

[psp48d at bangor.ac.uk]

Hi,

I have designed a task-switching paradigm, involving 3 lists (one for each
task). Each list contains 9 cues and 9 stimuli, and the list the stimuli is
chosen from is chosen by a randomisation using the following code:

Dim trialarray(2) as integer	

trialarray(0) = 1
trialarray(1) = 2
trialarray(2) = 3
Randomizearray trialarray
c.Setattrib "Lag_Condition", trialarray(1)

Dim Task
Task = c.GetAttrib ("Lag_Condition")


if Task = 1 then
Borderlist.Run c
elseif Task=2 then
Angledlist.Run c
else
Shadedlist.Run c
End if

This randomises on every trial, but how do I set the code so that it remains
random, but DOES NOT ALLOW the previous list to be relevant to the current
selection? I am trying to get it so the task never repeats, but remains random.
How is this done?!?!

Many thanks!

Jim Grange,
Bangor University
UK.



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