[Eeglablist] Full-epoch length single-trial corrections and assessing significance for frequency-bands

[Belen De Sancristobal]

Dear all,
I am following the Methods described in Grandchamp, R. and Delorme, A. Front Psychol, 2011.
In particular, I am applying the full-epoch length single trial correction using eqs. 1, 3, 5 and 6 (this is what is called ERSP_Full-log in the paper). I follow this equations for each frequency and channel of interest individually. However I am interested, at the end, on grouping my results in 6 frequency bands (delta, theta, alpha, low-beta, high-beta and low-gamma). Here is my first question: Can I average my ERSP across frequencies within each band after applying eq. 6 and not before? This means that I do my average across frequencies after I average across trials.  
I am building my own Matlab code in order to make sure that I understand the steps.

My second concern is regarding the computation of significance. Here I am following the baseline permutation method described in the same paper. It is said that prior to computing statistics, single-trial power estimates need to be baseline corrected. Since to compute my ERSP estimates I followed the full-epoch length single trial correction procedure, I did not divide by the baseline (actual pre-stimulus baseline) until I averaged across trials (classical baseline approach as opposed to single-trial baseline correction). Hence, I understand that to proceed with the statistics I have to, after doing the full-epoch length single trial correction, divide by real baseline on a single-trial basis as well. Is this correct?
Once I have done that I compute the surrogate distribution for my baseline period and compute the exact p-values for the original ERSP values from a Wilcoxon test. However, this original ERSP values are now the ones obtained from a single-trial baseline correction as opposed to baseline correction on the resulting trial averages. Does this makes sense or I am confused?
Because I am interested on frequency bands, for this statistical analysis I am already using ERSP signals that are averaged across frequencies within bands.

Hope it is clear enough.
Thanks a lot,
Belen S