[Eeglablist] Saccades from eog data

[Arnaud Delorme]

Dear Scott,

I would probably low pass filter below 10 Hz to be sure to remove high frequency parameters before doing this test. Also this will depend on your data sampling rate. 15 points at 256 Hz is 60 ms but it is only 30 ms at 512 Hz.

Then you can try something like if you want to use the first channel

diffData = diff(EEG.data(1,:));
index = 1;
while index < EEG.pnts-14
	if all(diffData(index:index+14) > 0)
		EEG.event(end+1) = 'blink';
		EEG.event(end).latency = index;
		index = index + EEG.srate; % jump by one second
	end;
	index = index + 1;
end
EEG = eeg_checkset(EEG, 'eventconsistency');
[ALLEEG EEG CURRENTSET] = eeg_store(ALLEEG, EEG, CURRENTSET);
eeglab redraw

Best regards,

Arno

On Jun 21, 2011, at 2:29 PM, Scott Munro wrote:

> Hello,
>   We have a set a MEg data from a CTF machine that we have imported into eeglab.  We are trying to isolate the saccades in the horizontal eog channels.  I am hoping that eeglab will allow us to do that.  Up until now we have just been looking at a plot of the eog value and manually identifying the saccades, this of course is less than Ideal.
> 
>   No calibration routine was done so we found a paper that gives some criteria for isolating saccades.  Basically they label the start of a saccade when the voltage increased (or decreased) for 15 consecutive time points and the chnage over those 15 times points was greater than 100 micro volts.  We were hoping to use the same criteria.
> 
>   I am extremely new to eeglab and this type of data.  I have yet been able to find a way to implement a search of teh data for situations that meet this criteria.  
> 
>  Any help would be greatly appreciated.
> 
>   Thank you in advance.
> 
>    Scott Munro
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