Hi Keith,<br><br>If you are interested in model comparison, then I&#39;d say you can use whichever number of subjects, irrespectively of the number of connections. In fact, you can make statistical inferences about models in only one individual subject. <br>

However, if you then want to go on and do classical statistical tests on the connectivity parameters, then it might be a good idea to increase the number subjects/parameters per cell.<br><br>I&#39;m CCing this to the SPM list in case other people want to comment on it.<br>

Hope this helps!<br>

<br>Marta<br><br><br><div class="gmail_quote">On 9 May 2011 10:44, Keith Kawabata Duncan <span dir="ltr">&lt;<a href="mailto:[log in to unmask]" target="_blank"><a href="/cgi-bin/wa-jisc.exe?LOGON=A3%3Dind1105%26L%3DSPM%26E%3Dquoted-printable%26P%3D3041239%26B%3D--20cf30549f05459f9604a2ee19ab%26T%3Dtext%252Fhtml%3B%2520charset%3DISO-8859-1%26pending%3D" target="_parent" >[log in to unmask]</a></a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">



 Hi Marta,<br>
<br>
Maria thought you might be able to help me with a DCM question. I was wondering if increasing the number of connections in a model requires increasing the number of subjects - a bit like increasing the number of cells in a factorial design?<br>



<font color="#888888">
<br>
Keith<br>
</font></blockquote></div><br><br clear="all"><br>-- <br>Dr. Marta I. Garrido<br>Research Associate<br>Wellcome Trust Centre for Neuroimaging<br>University College London<br>12 Queen Square<br>London<br>WC1N 3BG<br>United Kingdom<br>



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