thanks for your help.
I have one more question. if i compare 16 trials of say color wrong with 164 trails of read the words, would the result be the same as using 64 say color wrong with 164 trails of read the words. Does trial numbers make any differece with the result?
Thanks in advance.
bing
----- Original Message -----
From: "Stephen J. Fromm" <
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Date: Wednesday, September 23, 2009 8:50 am
Subject: Re: questions of event-related analysis
To:
[log in to unmask], Bing Ye <
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> On Tue, 22 Sep 2009 18:21:58 -0400, Bing Ye <
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> wrote:
> >Hi all:
> >
> >I am doing event-related analysis for my study. Subjects are
> doing a stroop
> test. there are two conditions reading the word and saying the
> color . I want
> to compare the incorrect responses when they say the color ink
> and correct
> responses when they read the word. but sometimes they only made
> a few
> mistakes when the say the color ink. My question is can i
> compare 3 incorrect
> responses to 64 corect responses. Would it yield the same or
> similar result
> when i compare 60 incorrect responses to 64 correct responses?
>
> It might have the same result, in the sense that the estimator
> is unbiased, but
> there's no way you can compare using only 3 incorrect responses--
> -the
> sample size is far too small to get anything useful. There
> are various rules of
> thumb in fMRI (which is what I assume you're doing), one of
> which is how
> many trials of a given condition you need.
>
> >
> >Could anyone let me know?
> >
> >Thanks a bunch.
> >
> >bing
> >
>
>
>
