multiplotTFR for 128 channel Neuroscan EEG data ???

[Ingrid Nieuwenhuis]

Hi Carina,

Thanks for sending me the data. Indeed the biosemi 128ch layout doesn't
correspond to your layout. You have 128 channels labeled from 1 to 128. If
you open biosemi128.lay in a text-editor you can see that this layout file
has 150 channels labeled from A1 to P7. The labels in your data
(TFRmult.label) and the labels in the layout file don't match, that's why
you got an empty figure (I'll add an error in the plot function, so that
when no labels match you'll get an error message in the future).

So what you have to do now is to make your own layout file that matches the
data; with the correct x and y coordinates of the 128 channels and the same
label names as in your data. Just as an illustration I attached an adapted
version of the biosemi128.lay file, with only the first 128 channels, and
labels 1 to 128, just as in your data. With the following configuration:

cfg8 = [];
cfg8.baseline   = [0 0.1];
cfg8.xlim       = [0 0.3]
cfg8.ylim       = [15 29];
cfg8.zlim       = [-100 100];
cfg8.showlabels = 'yes';
cfg8.layout    = 'testlay128.lay';

I got the attached figure from your data.

Good luck,
Ingrid



-----Original Message-----
From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Robert Oostenveld
Sent: Wednesday, May 24, 2006 8:57 PM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: Re: [FIELDTRIP] multiplotTFR for 128 channel Neuroscan EEG data ???

Hi Carina

Are you sure that the biosemi 128ch layout corresponds with your
electrode layout? Open the layout file in a tetx editor and look at
http://www2.ru.nl/fcdonders/fieldtrip/doku.php?
id=fieldtrip:documentation:frequently_asked_questions#what_is_the_format
_of_the_layout_file_which_is_used_for_plotting

I suggest that you try the elec1010.lay or elec1005.lay, or even
better, that you construct your own layout file corresponding with
your own electrode locations.

Robert


On 24 May 2006, at 12:29, Carina Graversen wrote:

> Hi.
>
> I'm trying to use the Fieldtrip program to create a wavelet plot of
> my EEG
> data.
>
> I have used it previously for 64 channel recordings, but now I'm
> working
> with 128 channels of data, which is causing me some problems. The
> only thing
> I have changed is the command:
> cfg8.layout    = 'biosemi128.lay';
>
> But now the figure only outputs a grey page with no Time-Frequency
> distributions at all.
>
> Can anyone tell me what I'm doing wrong - below is a complete list
> of all
> the commands I use  :o).
>
> Best Regards,
> Carina Graversen
>
>
>
>
> %
> **********************************************************************
> ***
> % EVENTRELATEDAVERAGING
> %
> **********************************************************************
> ***
> cfg1 = [];                                                     % empty
> configuration
> cfg1.datafile                      = 'test128.eeg';            %
> 128 channel
> Neuroscan eeg file
> cfg1.headerfile                    = 'test128.eeg';
> cfg1.channel                       = 'all';
>
> dataFIC = preprocessing(cfg1);                                 %
> Preprocess!
>
> cfg2 = [];                                                     % empty
> configuration
>
> avgFIC = timelockanalysis(cfg2, dataFIC);
>
>
> % %
> **********************************************************************
> ***
> % % WAVELET
> % %
> **********************************************************************
> ***
> cfg7 = [];
> cfg7.output     = 'pow';
> cfg7.method     = 'wltconvol'
> cfg7.foi        = 1:2:30;
> cfg7.t_ftimwin  = 5./cfg7.foi;
> cfg7.tapsmofrq  = 0.4 *cfg7.foi;
> cfg7.toi        = 0:0.01:0.5;
>
> TFRmult = freqanalysis(cfg7, avgFIC);
>
> cfg8 = [];
> cfg8.baseline   = [-0.5 0.5];
> cfg8.xlim       = [0 0.5]
> cfg8.zlim       = [-3e-27 0.2];
> cfg8.showlabels = 'yes';
> cfg8.layout    = 'biosemi128.lay';
>
> multiplotTFR(cfg8, TFRmult);
>

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