[Eeglablist] topo maps of grand averaged data

[Hamish Innes-Brown]

The way I did this a while ago (possibly not the BEST way) was to  
load all my subject averages for a given condition into the EEG  
structure.

I did this pretty simply like this:

% script for plotting the tones and word averages quite nicely.

% first load them all in
path = 'c:\_CAPAH\avg\';
cd(path)
wordsList=dir(fullfile(path,'*W.avg'));
tonesList=dir(fullfile(path,'*T.avg'));


for i = 1:size(wordsList,1)
     wavg(:,:,i) = loadavg(wordsList(i).name);
end

for i = 1:size(tonesList,1)
     tavg(:,:,i) = loadavg(tonesList(i).name);
end





In tis case I searched the directory for all *W.avg files and *T.avg  
files and loaded them into separate matrices using the EEGLAB  
"loadavg" command.

Then you go into the  File -> Import data -> From ASCI or matlab array

and type the name of your matrix into the field and off you go.  You  
will probably want to load a standard electrode locations file as  
well if you want to use topoplot.

It might be worth keeping in mind that you're putting avgerage data  
into a structure that was always meant to contain single-trials, and  
so you wouldn't want to do anything much apart from plot the data  
using this method.  I'm not sure, but I imagine if you were to run  
ICA on this the output might not be what you expect.  I haven't  
really thought about that though.


-hamish-



On 23/02/2006, at 12:40 PM, Clayton Hickey wrote:

>
> Hello Everyone,
>
> I have a potentially simple question regarding grand averaging...
>
> I'm in the relatively late stages of analyzing a dataset and have  
> created grand averaged waveforms. My question is this: is there an  
> easy way to create topo maps from the grand averaged data?  
> Currently I am creating an empty EEG structure, 'manually'  
> averaging the datasets, and placing this into the empty  
> structure... this entails copying a lot of other variables, and all  
> in all is a bit of a hassle. As eeglab has in general a high-level  
> of functionality, I've got a feeling I'm missing something...
>
>
> thanks in advance for any suggestions,
>
> Clayton Hickey
> Human Electrophysiology Lab
> Simon Fraser University
> Vancouver, Canada
>
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Hamish Innes-Brown
Mental Health Research Institute
National Neuroscience Facility
Level 2, 161 Barry St
Carlton South VIC 3053
Australia
+61 3 8344 1881  hinnesbrown at gmail.com

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