[Eeglablist] Plotting ERSPS averaged across several channels

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


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] = 

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.



Tom Bullock, PhD


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

bullock at psych.ucsb.edu

More information about the eeglablist mailing list