[Eeglablist] eeg data statistic analysis

[Antonella Rosmino]

Dear EEGlab community,
I am writing in the hope that you can help me clarify my ideas about the steps preceding or following the extraction of EEG data characteristics. Data collected from a 60-channel headset was divided into 2-second epochs, and I obtained as output the calculation of the average frequency of each individual stimulus per subject. The goal would be to understand how each modality (visual, auditory, or audiovisual) in which the stimulus is presented affects the average alpha, beta, and theta frequency bands of all subjects.
Now, please excuse me, but I am neither an engineer nor a neuroscientist; I am working with EEG data as a designer.
So, before proceeding with the statistical analysis of the data (ANOVA repeated measures (Friedman)), I would like to understand what steps I should take and when. Should the log10 function always be applied, even if I assume a non-normal distribution of the data? (Do you have any reference studies?) Should the standard deviation be applied? But when should the normality distribution check be done, if it needs to be done?
Do you know of any similar studies that follow the same objectives that I could use as examples?

I hope you can help me in some way!
I am glad if you have managed to follow me this far!

Thank you.
Best regards,
Antonella