<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Andrea,<div><br></div><div>¿Did you normalize the volume of the individuals after source reconstruction and before doing statistics? If not, this might explain the difference.</div><div><br></div><div>best,</div><div><br></div><div>Stephan</div><div><br></div><div><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><div>________________________________________________________</div><div>Stephan Moratti, PhD<br><br></div><div>see also: <a href="http://web.me.com/smoratti/">http://web.me.com/smoratti/</a><br><br></div><div>Universidad Complutense de Madrid</div><div>Facultad de Psicología</div><div>Departamento de Psicología Básica I</div><div>Campus de Somosaguas</div><div>28223 Pozuelo de Alarcón (Madrid)</div><div>Spain</div><div><br></div><div>and</div><div><br></div><div>Center for Biomedical Technology</div><div>Laboratory for Cognitive and Computational Neuroscience</div><div>Parque Científico y Tecnológico de la Universidad Politecnica de Madrid<br>Campus Montegancedo</div><div>28223 Pozuelo de Alarcón (Madrid)</div><div>Spain<br><br><br>email: <a href="mailto:smoratti@psi.ucm.es">smoratti@psi.ucm.es</a><br>Tel.: +34 679219982</div></div></span>
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<br><div><div>El 04/04/2013, a las 14:18, Andrea Brovelli escribió:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div> Dear all,<br><br>I used DICS and compared the quality of the beamforming using two different source spaces (3D grids):<br><br>1) MNI template space as described in <a href="http://fieldtrip.fcdonders.nl/example/create_single-subject_grids_in_individual_head_space_that_are_all_aligned_in_mni_space">http://fieldtrip.fcdonders.nl/example/create_single-subject_grids_in_individual_head_space_that_are_all_aligned_in_mni_space</a><br><br>2) Single subject 3D grid using anatomical MRI<br><br>The number of sources in the two models is similar (approx. 3500 sources). However, the results using the MNI template are less significant. That is, the statistical analysis testing a significant increase in power post-stimulus with respect to baseline give higher p-values (in some region of interest).<br><br>Questions:<br><br>Does anyone know why ?<br><br>Is the use of the MNI template the only (and best) way to allow statistical analysis across subjects in the source space ?<br><br>thanks a lot<br><br>Andrea<br><br><br><br>-- <br>_______________________________________________<br>fieldtrip mailing list<br><a href="mailto:fieldtrip@donders.ru.nl">fieldtrip@donders.ru.nl</a><br>http://mailman.science.ru.nl/mailman/listinfo/fieldtrip<br></div></blockquote></div><br></div></body></html>