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<div class="pre" style="margin: 0; padding: 0; font-family: monospace">Hello fieldtrippers ,<br /> <br /> For my Phd , I am trying to investigate the dynamics of alpha oscillations during anticipatory attention. I have analysed the data in the sensor level and based upon these analyses I have define time-frequency windows of interest to which I have applied the DICS beamformer.<br /> <br /> Based on statistical results, I have defined regions of interest (the left Heschl Gyrus, for example). Now I would like to have a look at the time couse of these sources.<br /> <br /> I have followed this tutorial: <a href="http://www.fieldtriptoolbox.org/tutorial/salzburg?s[]=virtual&s[]=sensors" target="_blank" rel="noreferrer">http://www.fieldtriptoolbox.org/tutorial/salzburg?s[]=virtual&s[]=sensors</a><br /> <br /> However, there is a step I would like to expert opinions. In the tutorial, after having defined voxels of interest , they have re-calculated the leadfield for these voxels. (let's call that method A)<br /> <br /> Should this operation be different to Method B which involves marking only the voxels of interest in the leadfield (that has been used for the DICS) as inside the brain?<br /> <br /> I've tried both methods, and results are different. So I would like to know why such difference exists and which is method is better?<br /> <br /> Also in the aforementioned tutorial , there is this:<br /> <br /> cfg.grid.pos=[btiposCML;btiposHGL;btiposHGR]./1000; % units of m<br /> <br /> Which I don't think is correct since conversion should be done from mm to cm (if we follow the tutorial)<br /> <br /> Thank you very much<br /> <br /> <br /> Hesham ElShafei</div>
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