[Eeglablist] Using Topoplot() function for Non-ICA data

[Allan Campopiano]

Hi Neha,

It seems like you want SD across trials for each electrode, but if I
misinterpreted that, let me know. Basically, you can use topoplot to plot
any values as long as you have channel locations and some data vector that
is posing as EEG data. So something like this would work.

% your array of SD values
SD=std(EEG.data,1,3);

% Say you want to plot at 100ms. Convert ms to time point (see
pop_topoplot).
TimePt=round((100/1000-EEG.xmin)/(EEG.xmax-EEG.xmin) * (EEG.pnts-1))+1;

% change colormap limits to whatever you want (MinVal MaxVal)
figure; topoplot(SD(:,TimePt),'Your_Channel_Locations_File', 'shading',
'interp', 'maplimits', [MinVal MaxVal]);
colorbar

If you want more of a grid style figure so you can see the SD values across
trials for every latency you could do
figure; imagesc(SD)
set(gca,'YDir','normal')

Also type help surf if you want 3D grid style figures.

Sincerely,
Allan




*Allan Campopiano* | Electrophysiology Technician-Analyst
Laboratory of Cognitive and Affective Neuroscience
Brock University | Psychology Department | 500 Glenridge Ave.
St. Catharines, ON Canada L2S 3A1
*T* 905-688-5550 x3451 *F *905-688-6922

On Sun, Feb 22, 2015 at 9:21 AM, Neha Tadimeti <nehatadimeti at gmail.com>
wrote:

> Hello,
>
> I am a graduate student at Rutgers University. I am currently doing a
> research on EEG - BCI data.
>
> I have calculated the mean and standard deviation of the distribution for
> each electrode data for each trial. Now I wish to visualize how the spread
> (Standard deviation) is changing across trials at each electrode on the
> brain. I basically want to color code the brain with standard deviation as
> its parameter.
>
> I tried using topoplot() function as a command line by giving my
> parameters as input instead of ICA data. It does not work that way.
>
> Can anybody suggest if EEGLAB can help me plot 2-D or 3-D images of
> non-ICA data. If not, I would really appreciate if any alternative methods
> are suggested.
>
> Thank you.
>
> Regards,
> Neha Tadimeti.
>
>
>
>
>
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