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

[Stephen Politzer-Ahles]

Hello Neha,

I'm not sure about pop_topoplot, but topoplot() takes a 1-dimensional
vector (i.e., a 64x1 array, if you have 64 channels), so you can't plot all
30 trials in a single plot this way. You could make a topoplot of a single
trial's standard deviation:

topoplot( EEG.data(:,1), EEG.chanlocs, other options... )

or you could instead change your data to a 64x1 matrix representing the
standard deviations across all trials (instead of a 64x30 matrix with
standard deviation for each trial) and plot that.

Others on the list might have some other solutions, but those are the ones
I'm aware of.

Best,
Steve



Stephen Politzer-Ahles
New York University, Abu Dhabi
Neuroscience of Language Lab
http://www.nyu.edu/projects/politzer-ahles/

On Mon, Feb 23, 2015 at 7:29 AM, Neha Tadimeti <nehatadimeti at gmail.com>
wrote:

> Hello,
>
> Thank you very much for the reply.
>
> My data has the dimensions (64 X 30), where 64 corresponds to the number
> of electrodes and 30 corresponds to the standard deviations corresponding
> to 30 trials. I have 7 sets of such (64 X 30) matrices. I wish to have a
> scalp plot of these seven blocks and compare the changes in the spread.
>
> I tried *pop_topoplot(EEG,0, [1:64],[8 8],'stdvalues'
> ,0,'electrodes','on'); *I am pretty sure I have not defined the
> parameters correctly. I would be greatly elated if you could help me
> rectify.
>
> Thank you.
>
>
>
> On Sun, Feb 22, 2015 at 10:11 PM, Stephen Politzer-Ahles <spa268 at nyu.edu>
> wrote:
>
>> Hello Neha,
>>
>> This should be possible. topoplot() takes a vector of values (typically
>> amplitudes, or mean amplitudes over a time window) for each channel, so it
>> should work the same if you just put in the standard deviations instead.
>>
>> What "does not work" about what you tried? What was your code, what error
>> did you get, etc.?
>>
>> Best,
>> Steve
>>
>>
>>
>> Stephen Politzer-Ahles
>> New York University, Abu Dhabi
>> Neuroscience of Language Lab
>> http://www.nyu.edu/projects/politzer-ahles/
>>
>> On Sun, Feb 22, 2015 at 6:21 PM, 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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>>
>>
>
>
> --
>
> T.Neha,
>
> B.Tech ECE (2010-14),
>
> Amrita University,
>
> Kerala.
>
>
>
>
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