[FieldTrip] fieldtrip Digest, Vol 30, Issue 20

[Eric Maris]

Hi Eelke,

It all depends on the null hypothesis that you want to test. It's better
to discuss this with you in person or at some meeting with other
colleagues (for non-Donders Discussion List readers, Eelke and I work at
the same institute), because at the end it is a matter of deciding on what
is an interesting null hypothesis (both for you and the reviewers of your
paper).

I remember a discussion with a colleague about the same issue (using
first-level t-statistics at the second level), and he was quite unhappy
when I questioned this approach (by asking whether this is really the null
hypothesis he was interested in). At the end, it turned out that he also
had tried the standard approach (using only condition means) but this did
not result in a significant p-value.

Best,

Eric


> -----Original Message-----
> From: eelke.spaak at gmail.com [mailto:eelke.spaak at gmail.com] On Behalf Of
> Eelke Spaak
> Sent: donderdag 16 mei 2013 16:44
> To: Eric Maris; FieldTrip discussion list
> Subject: Re: [FieldTrip] fieldtrip Digest, Vol 30, Issue 20
> 
> Hi Eric,
> 
> Thanks, that's what I expected. However, that approach does not take
> into account the different between-trial variances in the different
> subjects. What would you recommend to take those into account?
> 
> Best,
> Eelke
> 
> On 16 May 2013 16:31, Eric Maris <e.maris at psych.ru.nl> wrote:
> > Hi Eelke,
> >
> > This not valid. At the second level, you must use the condition means
> (per subject) as the observations about which you have a hypothesis and
> which therefore have to be permuted.
> >
> > Eric
> >
> >
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