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    Hi FTers,<br>
    <br>
    I'd like to do two sorts of correlation calculations, and was 
    wondering if there's any easy way to do this within FieldTrip. <br>
    <br>
    1) I'd like to calculate the correlation between performance over
    trials and power within a specific frequency over trials. So I have
    the performance measure per trial, and my chan*freq measure after
    freqanalysis. So for each channel I have a series of power values
    (trials) and I have a series of performance measures (per trial),
    and now like to know (first within, and then over subjects) which
    channel's frequency power follows (correlates) with the performance.<br>
    <br>
    From the <a
      href="http://fieldtrip.fcdonders.nl/walkthrough#correlation">walkthrough</a>
    I understand I can give in these performance measures through the
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            font-family="'Calibri-Italic'" font-size="11.04">;), but
            which method to use for ft_freqstatistics? I don't see
            statistics = 'correlation' or 'pearson' or 'spearman' in
            method = 'analytic. Also how to make the design to correlate
            over trials?<br>
            <br>
            2) I'd like to calculate the correlation between the score
            on repeated questionnaire over participants with power
            within a frequency. So I have several power values per
            participant for each channel, and the repeated scores on the
            questionnaire for each participant. And now I'd like to
            calculate a value per channel reflecting the correlation
            over the repeats of the questionnaire and over participants.
            <br>
            <br>
            Any idea on FieldTrip settings? Both in general, is there a
            correlation statistics implemented, and more specifically
            for my question, how would I make the appropriate designs?<br>
            <br>
            Thanks so much!<br>
            Ingrid<br>
          </tspan></text></g></g>
    <pre class="moz-signature" cols="72">-- 
Ingrid Nieuwenhuis PhD
Postdoctoral Fellow
Sleep and Neuroimaging Laboratory
Department of Psychology
University of California, Berkeley
California 94720-1650
Tolman Hall, room 5305</pre>
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