Eye blink duration

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g.usai
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Joined: Thu Mar 04, 2021 10:57 am

Eye blink duration

Post by g.usai »

I'm trying to figure out if it's possible to get the duration of each eye blink using the timestamp associated with it. Is it possible to get it by doing the difference between the timestamp associated with the eye blink and the timestamp associated with the next or previous sample in the csv?
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James
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Joined: Wed Jan 02, 2013 9:06 pm

Re: Eye blink duration

Post by James »

Eye blinks are consider instant single events by Interaxon's algorithm. There's no on/off for eye blink.
If you wanted to do your own calculations on the RAW EEG, then I think it might be possible for you work this out.
Looking at the EEG, the two are noticeably different.
Below is a normal fast blink:
fast-blink.png
fast-blink.png (11.48 KiB) Viewed 793 times
and a slow blink:
slow-blink.png
slow-blink.png (12.53 KiB) Viewed 793 times
You can clearly see the difference that the EMG of the eyelid muscles makes to the graph, so you'd just need some math to work it out.

Note that by default Mind Monitor only saves data in the CSV file every second. In order to do this kind of EEG analysis, you'd need to increase the "Recording Interval" in settings to "Constant" to get the full 256Hz RAW EEG data required. Then you could process it in something like MATLAB to work out the blink duration.
g.usai
Posts: 2
Joined: Thu Mar 04, 2021 10:57 am

Re: Eye blink duration

Post by g.usai »

Thank you
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