[Eeglablist] newtimef with large frequency windows

[Zachary Moran]

Hi all,


At the moment I'm working on a project in which I'm trying to get ERSP
estimates around some early evoked potentials (e.g., between 20 and 100 ms).
Though I'd like to implement a frequency window of 3 to 60 Hz, when I
attempt to do so, EEGLAB forces the output to fall within a window of 358.0
to 442.0 ms.  Unfortunately, the only way I'm able to get to earlier
time-points is to increase my minimum frequency to around 12 Hz thus
allowing for an overall larger time window.  However, I have seen the sort
of analysis that I'm looking for done (I think in EEGLAB, since it used ERSP
and ITC specifically) by Brockhaus-Dumke et al. (2008)  "Sensory gating
revisited: Relation between brain oscillations and auditory evoked
potentials in schizophrenia."  I've included an example of my script below:

<<figure; pop_newtimef( EEG, 1, 1, [-200  1000], [3         0.5] ,'type',
'phasecoher', 'topovec', 1, 'elocs', EEG.chanlocs, 'chaninfo', EEG.chaninfo,
'title','ERSP and ITC','padratio', 1, 'plotphase','off','freqs',[3 60]);>>

My dataset is sampled at 1000 Hz and has 1201 frames per epoch.  Does anyone
have any experience with this who knows how I might get around this problem
or any way of recentering the output window around desired ERP components
(e.g., from 75 to 125)?  Any help or information would be very greatly
appreciated.


Thank you very much,


Zach


Zachary Moran
Graduate Student
University of California-Los Angeles
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