[Eeglablist] Problem with base line in time-frequency

[Johan.poncelet]

Ok, thanks.
I will waiting for the baseline possibility.

For the limitation for the windows in time frequency:
 Ok there is a limit because of the wavelet. You speak about 500ms on 
each side. I have epoched from -1000 to 2000 ms. So I should have had a 
result in time frequency from -500 to 1500. And I obtained an analyse 
from -126ms to 1200. Is this normal?

Best regards
Johan


Arnaud Delorme a écrit :
>
>> I have epoched my data from -1000 ms to +2000ms in order to have a 
>> very large one.
>> When I apply the time frequency function (study, compute ERSP), I 
>> obtain a time freq representation from -126ms to 1200ms maxi.
>>
>> Why?
>>   
>
> This is because the time-frequency decomposition trim the time window. 
> If your lower frequency is 3 Hz and you have a 3-cycle wavelet (at 3 
> Hertz) for instance, this wavelet duration is 1000 ms (1 s). This 
> means that 500 ms will be trimmed on each side.
>
>> Now i would like to do different ERSP. I would like that the [-1000, 
>> -500] period to be my baseline. And then have a representation from 
>> -500 to +1500.  Is it possible? I have tried with the option 
>> 'baseline' in the ERSP box but EEGlab give me error message.
>>   
>
> The baseline cannot be entered yet through this interface but we have 
> entered an bug repport for enhancement so this should be possible soon.
>
> Best regards,
>
> Arno
>


-- 
Johan Poncelet
Laboratoire Neuroscience et Systèmes Sensoriels
CNRS UMR 5020
Equipe Variabilité et Plasticité de l'Audition
Université Claude Bernard Lyon 1
50, avenue Tony Garnier
69366 LYON cedex 07
Tel 06 81 88 66 92
Johan.poncelet at olfac.univ-lyon1.fr
Johan.poncelet at gmail.com