I conducted an experiment on a sample of people (N) performing two different tasks (t1 and t2). For each task, each subject performed the task under two conditions (c1 and c2). I recorded EEG data while participants performed the experiment.
I am interested in comparing the two conditions for task1 (t1) and for task2 (t2) separately (c1 vs c2 for each task separately).
problem1: I would like to compare three calculated indices under five frequency bands.
Attempted solution: I calculated 15 p-values for each task.
problem2: I would like to compare one index under two conditions (c1 vs c2) for 64 electrodes for each task separately. I am considering only one frequency band which I found important from the results of problem 1.
Attempted solution: I calculated 64 p-values for each task.
Question: I am not sure how to count the number of comparisons. For Problem 1, are the number of comparisons 15 or 30?
For Problem 2, are the number of comparisons 64? Or 64 x 2? Or 64 x 2 x5?
It gets really confusing when the number of parameters and dimensions increase!