Dear Melmoth, <br><br>Non-linear DCM is a fairly recent extension to DCM for fMRI where you can specify regions exerting an influence on the coupling between other regions. <br><br>The article introducing this extension is: <br>
<br style="font-family: arial,helvetica,sans-serif;"><strong style="font-family: arial,helvetica,sans-serif;">Stephan et al. Nonlinear Dynamic Causal Models for FMRI</strong><span style="font-family: arial,helvetica,sans-serif;">.<b>
</b></span><b><em style="font-family: arial,helvetica,sans-serif;">NeuroImage</em><span style="font-family: arial,helvetica,sans-serif;">,
42(2):649-662,
2008.</span><br style="font-family: arial,helvetica,sans-serif;"><br></b>best wishes,<br>Hanneke<br><br><br><br><div class="gmail_quote">On Thu, Jul 22, 2010 at 1:13 PM, Dr Melmoth <span dir="ltr">&lt;<a href="mailto:[log in to unmask]"><a href="/cgi-bin/wa-jisc.exe?LOGON=A3%3Dind1008%26L%3DSPM%26E%3Dquoted-printable%26P%3D208120%26B%3D--0015175d077e816dfe048ceaec66%26T%3Dtext%252Fhtml%3B%2520charset%3DISO-8859-1%26pending%3D" target="_parent" >[log in to unmask]</a></a>&gt;</span> wrote:<br>
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Dear all<div><br></div><div><div>In specifying a DCM model, an option appears, after I have specified my matrices A, B and C:</div><div><br></div><div>&quot;Effects of attention on regions and connections</div><div>Non-linear DCM?&quot;</div>
<div><br></div><div>If I select yes I am then asked to specify some further matrices, e.g. &#39;Effects of V1 activity on connections&#39;</div><div><br></div><div>If I select no it progresses straight to slice timing.</div>
</div><div><br></div><div>The manual doesn&#39;t cover this.  Can anyone explain what this is? Or point me to some materials which do?</div><div><br></div><div>Many thanks</div><div><br></div><font color="#888888"><div>Melmoth</div>
</font><div><br></div><div class="hm"><div><br></div><div><br></div><div><br></div> 		 	   		  <br><hr>Get a new e-mail account with Hotmail - Free. <a href="http://clk.atdmt.com/UKM/go/197222280/direct/01/" target="_blank">Sign-up now.</a></div>
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</blockquote></div><br><br clear="all"><br>-- <br>Hanneke den Ouden, PhD<br><br>Donders Centre for Cognitive Neuroimaging<br>PO Box 9101,  6500 HB Nijmegen<br>The Netherlands<br>Tel: +31 (0)24 36 10983<br>Fax: +31 (0)24 36 10989<br>
<br>Visiting address:<br>Trigon, room 0.64 <br>Kapittelweg 29, Nijmegen<br>