[Eeglablist] How to epoch EEG data based on the latency of square waves in a trigger channel

[John Johnson]

Hi Kaelasha,

Here is some code I use.
https://gist.github.com/JohnAtl/328be258db7c2ac83d2ce5227bf51303#file-hl1_to_events-m

Regards,
John

John T. Johnson
PhD Candidate - Cognitive Motor Control Laboratory
Lab TA NEURO 3010 Neuroscience Methods
School of Biological Sciences
Georgia Institute of Technology
john.johnson at gatech.edu
he/him/his

On 3 Mar 2020, at 21:13, Kaelasha Tyler wrote:

> Hi all,
>
> I am wanting some advice on epoching EEG data based on the latency of
> square waves in a trigger channel. How would you do it?
>
> I am using a Compumedics Profusion4 software for EEG recording and
> receiving triggers into the data as brief square waves sent as a TTL 
> pulse.
> These square waves arrive in a separate trigger channel.
> Different conditions are marked by square waves with different 
> voltages.
>
> Because there is no high level information on triggers in the data 
> set, I
> cannot just use Tools>extract epochs in EEGlab. Basically I need to 
> add
> that information, based on the latency and the voltage of the square 
> waves.
>
> I can easily create a short Matlab routine to pick out the latencies 
> of
> these square waves, and create a vector of these latencies. But then 
> how to
> get that in to the data set?
>
> Any suggestions?
>
> Thanks in advance!
>
> Kaelasha
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