What stat test to use for improved task?

I have an experiment where a group of subjects have to learn to associate some sounds to images (day, sound 1-image 1, sound2 -image 2, sound3-image3, sound4-image4). They do a memory test (we present sounds and images several times, including sound 5 - image 5, sound 6, image 6, which are controls and were not learned. If it is the correct pair they should mark yes, otherwhise, mark no). Then the subjects nap. During the nap I play sound 2 and sound4 so that the subjects can hear. They wake up and redo the test.

We test if drug playing sounds during napping increases memory by comparing the memory test before and after the nap. My hipothesis is that their accuracy on the memory test for associating sounds 2 to image 2 and sounds 4 to image 4 will be higher).

I need to find a statistical test to show that the memory test performance has increase in the pairs where the sounds where played. We can't infer anything about the distribution. So, I think a non parametrical test is what I need.

I know that ma matlab has a Kruskall-wallis function. But I don't think it is applicable to this test.

Can anyone guide me of what nonparametric test there is in matlab. to do so?

Thanks,

[John D'Errico]

This is the kind of question that would surely be best served by posting on a stats site, where you will find more people able to offer help. Only then would you worry about MATLAB, once you know what you need to do. And I would bet that any test you would find will be availble in some way. So first, learn what you need to do. Only then should you worry about the implementation specifics.

Answer 1

[Star Strider]

Theis seems to me to ba a paired test, so the Wilcoxon signed rank test (the signrank function) would likely be appropriate.

Another option could be Friedman’s test (the friedman function), however I am not certain that fits the design of your study.

(I am not currently posting this as an Answer because I am not certain that it solves the problem. If it does, I will move it to an Answer.)

[L]

Thanks @Star Strider! Your suggestion was very nice since the signrank function can do exaclty what I want. Please move it as an answer!

[Star Strider]

Thank you!