[Eeglablist] Plotting ERSPS averaged across several channels

Tom Bullock thomas.bullock at psych.ucsb.edu
Mon Nov 17 11:25:59 PST 2014


Hello,

I'm currently working with a STUDY with three groups and three 
conditions. I'm using the std_erspplot function to plot ERSPs.. When I 
input a single channel into std_erspplot, I get a 3x3 grid of ERSP 
plots, one plot for each channel and group e.g.

[STUDY erspdata ersptimes erspfreqs pgroup pcond pinter] = 
std_erspplot(STUDY,ALLEEG,'channels',{'Oz'});

I'd like to plot a separate ERSP for each condition and group, but with 
several channels averaged together (e.g. Oz, O1, O2, PO3, PO4) rather 
than just a single channel at a time.  However, when I select several 
channels, I get one ERSP plot for each individual electrode, averaged 
over all groups and conditions e.g.

[STUDY erspdata ersptimes erspfreqs pgroup pcond pinter] = 
std_erspplot(STUDY,ALLEEG,'channels',{'Oz' 'O1' 'O2' 'PO3' 'PO4'});

I've been through the documentation and cannot see a way to specify 
averaging across channels rather than across groups/conditions.  Is 
there a way to do this using the STUDY function?  One workaround migh be 
to create an averaged "channel" in my epoched dataset (e.g. channel 33 = 
mean(Oz, O1, O3,PO3, PO4)), recompute the ERSPS, and then plot that 
averaged "channel".  But before I do that, I just wanted to check if 
there's an faster, more flexible solution?

Any advice would be much appreciated.

Thanks!

Tom

-- 
Tom Bullock, PhD

https://labs.psych.ucsb.edu/giesbrecht/barry/Attention_Lab/Tom_Bullock.html

Postdoctoral Researcher, Department of Psychological and Brain Sciences,
University of California, Santa Barbara, CA 93106-9660

bullock at psych.ucsb.edu




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