[Eeglablist] Study statistics: factor assignment EEGLAB vs Fieldtrip statistics - bug?

[Kris BAETENS]

Dear users,

I'm exploring STUDY statistics for the first time in a 2x2 factorial design. I have sequentially compared "Compute 1st independent variable..." and "Compute 2nd independent variable...", using EEGLAB's permutation/Bonferroni option (n=1000, threshold = .05) and using Fieldtrip statistics (montecarlo, cluster correction, n=1000, threshold = .05).
The results are almost impossible to reconcile, unless what the EEGLAB statistics consider the 1st independent variable is the 2nd one for the Fieldtrip statistics option and vice versa. More specifically, the first independent variable in this example is associated with a somewhat left lateralized frontal effect for EEGLAB stats and an occipital effect for Fieldtrip stats, and the inverse is true for the second independent variable (in both cases with somewhat more significant channels for the Fieldtrip option, as would be expected, here). It would also seem that under the Fieldtrip option, the map displaying the significant channels has a title that intuitively corresponds to the factor of interest, whereas the EEGLAB option is counter-intuitive. To illustrate, in this 2 (alcohol versus no alcohol) by 2 (go versus nogo) design, the subplot showing the channels with significant differences between go and no go trials is entitled  "GoNoGo" for the Fieldtrip option, while the supposedly corresponding EEEGLAB statistics subplot is entitled "Alcohol".

Is this possibly an error? Not so difficult to disentangle in this case, but potentially critically confusing in case of factors with effects that are more difficult to disentangle...

Kind regards

Kris Baetens