Randomization problem. Is it complicated?

Hi all,

A question regarding the randomization with Matlab: I have created a script where I have 12 images and 12 sounds, combined into 24 trials. 1-1 1-2 2-1 2-2 3-3 3-4 4-3 4-4 And so on.... The script works very well and no bugs with psychtoolbox.

Any idea of how to randomise those 24 trials while avoiding 2 consecutive trials? For instance, randomise and avoid 3-4 and 4-4 or 4-3 to occur one after the other.

Looking forward for an answer :-)

Many thanks!

[Image Analyst]

What is your criteria for making sure one pair does not occur immediately after another pair? Why is image 4 and sound 3 not allowed to come after image 3 and sound 4? They're different images and sounds - nothing is consecutive.

Answer 1

[Walter Roberson]

For something like this, the easiest way is to loop, generating potential orders, exiting the loop if the order is acceptable and otherwise continuing to loop.

[LuS]

Hi, Thank you very much for your reply.

Here is what I tried and it is nit working :(

For trial=1:24
trialN=24
T=repmat(1:trialN, 1,2);
Trand=T(randperm(length(T)));
for K=1:length(Trand);
imtool(images{K});
end