[Eeglablist] manually adding channel location and event information

[Kaelasha Tyler]

Hi Mayuri,

To add channel locations, its edit>channel locations in EEGlab.
Then you can manually add the channel label near the top of the pop up box,
eg 'F3' as it corresponds to the channel number in your data, and this
channel number is indicated lower down in the pop up box. So you can go
through and add 'F3' for chan 1, 'F4' for channel 2, etc etc as it relates
to you data set.
You can then press 'Look up locs' button in the same pop up box and it will
add the channel location details provided these are part of the regular
10-20 system.
Then 'Ok' and it should have added these channel locations into your EEGlab
data.

I am not sure about visED, but when you say that your mat file contains
trigger pulse data, do you mean that one row of data in your mat file is a
pulse or square waves across various latencies?
If so, you could just manually work out the latency in your mat file by
writing a short script or even by plotting that one trigger channel and
manually detecting the latency of the pulses. Then recording those
latencies in a small matlab column matrix calling it latencyMatrix for
example?
Then you can add this into the eeglab .set file by running the following
short script when the file is currently open in EEGlab.
You could alter to your purposes:

for i = 1:40;% max = your number of triggers

    EEG.event(1,i).type = 10; %What ever you want to label the triggers in
your data

    EEG.event(1,i).latency = latencyMatrix(i, 1) % These values should just
correspond to the latencies of your triggers

    EEG.event(1,i).urevent = 10;

end

Then save the .set file in eeglab.

Other people may have an easier way of doing this?

Hope this helps.

Kae




On Sat, Feb 15, 2020 at 3:05 AM Mayuri Sivaraj <mayuri.sivaraj at cdu.edu.au>
wrote:

> Hello,
>
> I'm new to EEG signal processing and EEGLAB. I'm using EEGLAB to process
> the recorded EEG data. I have a few questions.  I tried to find answers to
> these questions however I was unsuccessful. kindly help me out in this.
>
> The Recorded EEG data is in matfile format (information contained in the
> file: trigger pulse data, stimulus data, 8 channel data). the mat file
> doesn't contain channel location information and event information.
>
>   1.  how to add channel location information manually? what file format
> is required ?
>   2.  I'm trying to add event information manually. visED plugin has been
> mentioned in some of the posts. how to use visED plugin in eeglab? I could
> not find online documentation on visED plugin.
>
>
> thanks in advance,
> mayuri
>
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