[Eeglablist] How to remove effect from one kind of stimulus

[Tarik S Bel-Bahar]

Hello Qin,

maybe this will be of use to you:
from my perspective, you should probably just not use the trials where
C occured.
If that is what you are trying to do, then you should only make epochs
for ERPs from the trials that have the A and B stimuli.

If by "effects" and "try to remove the effect of stimulus C"   you
mean that you tried
to do a difference wave (subtracting the ERP of trials with A and B
from the trials with A, B, C.

the following sentence that you wrote is difficult for me to understand:
"I have tried the method of removing the eyes blink,
but the effect of stimulus is not as strong as the eyes blink in one trial"
it's not clear what the following words mean: "effect" which effect ?
amplitude ? difference amplitude ?
it's also not clear what you're up to with eyeblinks. Eye blinks are
usually detected by an algorithm.
Trials with eyeblinks are usually removed or de-blinked before analyses.
So it's not clear why you are looking at a trial with an eyeblink and
the C stimulus,
when want you want to look at, I assume, are blink-free trials with
only A and B stimuli.

Best wishes!




On Tue, Jan 8, 2013 at 9:59 PM, PengMin Qin <qin.pengmin at gmail.com> wrote:
> Hello,
>
> I have one experiment including three kinds of stimuli: A, B and C. In the
> stimuli sequence, some stimulus C were near the stimulus A and stimulus B. I
> only want to know the effects from stimulus A and B. So I try to remove the
> effect of stimulus C, and use the remaining signal to make up a new dataset
> only including stimulus A and B.  I have tried the method of removing the
> eyes blink, but the effect of stimulus is not as strong as the eyes blink in
> one trial. This method may do not work. Would you like to give me some
> suggestions?
>
> Best,
> Pengmin
>
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