[Eeglablist] (no subject)

[Arnaud Delorme]

>1) The output from Plot->Channel properties shows the power spectrum (as
>computed using Matlabs' pwelch() function ).  The output is scaled in dB,
>and (for my data anyway) is negative at some frequencies (indicating a
>loss in power).  Just to be clear, is this because it uses some arbitrary
>value for its baseline?  I just want to make sure its not using the
>prestim interval.
>  
>
Yes, this is correct. This does not use any baseline. dB indicates here 
10*log10(power^2). We will change the axis label to make that the 
default instead of dB.

>2) The output from Plot > Time frequency transforms > Channel
>time-frequency shows another form of the power spectrum.  Again, just to
>be clear, does this one show the changes in post-stimulus power relative
>to the mean pre-stim interval?
>  
>
Yes, it does by default. You may enter " 'baseline', Nan " in the edit 
box of the time-frequency graphic interface to compute the absolute 
power value (in 10*log10(power^2) )

Best,

Arno