[Eeglablist] replicating EEGLAB stats on ERSP

[Delorme, Arnaud]

>  1.  Is my assumption correct that the tests performed were two-sided as after looking at the data returned from erspdata, I think the changes were in both directions however what showed up in significance was only after>before

Yes, the tests are two sided.

>  2.  I calculated individual ERSPs myself and compared it with ERSP data, the values are different even though the trend is the same. My values are smaller at each channel. I don't know what to make of it. What I noticed though was that the erspfreqs returned by the EEGLAB study was [2         2.18121168366910         2.37884220448729         2.59437920501642         2.82944511692498         3.08580937366862         3.36540172971081         3.67032678654271         4.00287983484530         4.36556413204400         4.76110974531056......] while when I used the same parameters in pop_newtimef they were integers
> 
> [2      3       4       5       6       7       8       9         10     11     12     13......], however both were of the size 34. Is there a reason for these discrepancies?

This is because at the STUDY level, EEGLAB will use a common baseline for both conditions (this is set by default but can be disabled).

>  1.  I did permutation tests myself on the values from erspdata for each channel (64 channels in total). I can't replicate the results. An example being for the LC condition EEGLAB STUDY returns the following as significant (after FDR)

There is some code to do comparison (unit test). You might want to check it out 

https://urldefense.com/v3/__https://github.com/sccn/eeglab-testcases/tree/master/unittesting_studyfunc/std_erspplot__;!!Mih3wA!AkR07dxHKvqgPS4-av7QWePEzo7xT4ysCMfpIX8HXHAvge6nRvDUy2jO70kccBFLvD0aIWy7ZKLYq9FW62R3D1sW$ 

Cheers,

Arno