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<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Dear dr. Maris,</span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>I would like to
ask a question</span><span lang=EN-US> </span><span lang=EN-US
style='font-family:"Calibri","sans-serif"'>regarding your</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>article:</span><i><span
lang=EN-US> </span></i><i><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Nonparametric
statistical testing of EEG- and MEG-data</span></i><span lang=EN-US
style='font-family:"Calibri","sans-serif"'> in Journal of</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Neuroscience</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Methods
2007. I hope you will answer it.</span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>My question is
about the following.</span><span lang=EN-US> </span><span lang=EN-US
style='font-family:"Calibri","sans-serif"'>I want to use the non-parametric
cluster analysis,</span><span lang=EN-US> </span><span lang=EN-US
style='font-family:"Calibri","sans-serif"'>the one you described in your
article, for my ERP analysis.</span><span lang=EN-US> </span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>In this</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>article
you quantified the difference between the two conditions (congruent and
incongruent)</span><span lang=EN-US> </span><span lang=EN-US style='font-family:
"Calibri","sans-serif"'>by calculating sample specific t-values, based on</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>the
t-distribution. These sample specific t-values were calculated based on a two
sided test statistic and an</span><span lang=EN-US> </span><span lang=EN-US
style='font-family:"Calibri","sans-serif"'>alpha of .05. Subsequently clusters</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>were
chosen</span><span lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>based
on the uncorrected critical t-value.</span><span lang=EN-US> </span><span
lang=EN-US style='font-family:"Calibri","sans-serif"'>This</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>uncorrected</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>critical
t-value</span><span lang=EN-US> </span><span lang=EN-US style='font-family:
"Calibri","sans-serif"'>is</span><span lang=EN-US> </span><span lang=EN-US
style='font-family:"Calibri","sans-serif"'>also</span><span lang=EN-US> </span><span
lang=EN-US style='font-family:"Calibri","sans-serif"'>based on a two sided test
statistic.</span><span lang=EN-US> </span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Now my question.
I understand that this uncorrected critical t-value threshold affects the
sensitivity of the statistical test rather than the validity. So is it also
possible to calculate the sample specific t-values belonging to</span><span
lang=EN-US> </span><span lang=EN-US style='font-family:"Calibri","sans-serif"'>the
one-sided test statistic, instead of two-sided? The same question accounts for
the uncorrected critical t-value used as threshold.</span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Thanks in
advance,</span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Best,</span><o:p></o:p></p>
<p><span lang=EN-US style='font-family:"Calibri","sans-serif"'>Emanuel</span><o:p></o:p></p>
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<span style='color:#1F497D'><o:p></o:p></span></p>
<p><o:p> </o:p></p>
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Het UMC St Radboud staat geregistreerd bij de Kamer van Koophandel in het handelsregister onder nummer 41055629.<BR> The Radboud University Nijmegen Medical Centre is listed in the Commercial Register of the Chamber of Commerce under file number 41055629.<BR>
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<p>The aim of this list is to facilitate the discussion between users of the FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis.</p>
<p> http://listserv.surfnet.nl/archives/fieldtrip.html</p>
<p> http://www.ru.nl/fcdonders/fieldtrip/</p>