<div dir="ltr"><div style="font-size:14px">Dear fieldtrip users,</div><div style="font-size:14px"><br></div><div style="font-size:14px">I tried using DICS beamforming on MEG resting state data of healthy controls.</div><div style="font-size:14px">(e.g. no task, no baseline, eyes opened)</div><div style="font-size:14px"><br></div><div style="font-size:14px">I analyzed to localize oscillatory sources using beamformer techniques according to the following tutorial. </div><div style="font-size:14px">(link: <a href="http://www.fieldtriptoolbox.org/tutorial/beamformer" target="_blank">http://www.fieldtriptoolbox.org/tutorial/beamformer</a>)</div><div style="font-size:14px">However, the output image was weird to be considered as resting data. I would like someone to help me through source localization procedure.</div><div style="font-size:14px"><br></div><div style="font-size:14px"><br></div><div style="font-size:14px"><b>Q1. Is there something wrong in my script as below? </b></div><div style="font-size:14px">cfg = [];</div><div style="font-size:14px">cfg.output = 'powandcsd';</div><div style="font-size:14px">cfg.method = 'mtmfft';</div><div style="font-size:14px">cfg.foilim = [8 12];</div><div style="font-size:14px">cfg.tapsmofrq = 2;</div><div style="font-size:14px">cfg.channel = {'MEG'};</div><div style="font-size:14px">cfg.keeptrials = 'yes';</div><div style="font-size:14px">fft_rest = ft_freqanalysis(cfg, data_clean); % resting state MEG data (after preprocessing)</div><div style="font-size:14px"><br></div><div style="font-size:14px">%% Computing the leadfield matrices</div><div style="font-size:14px">cfg = [];</div><div style="font-size:14px">cfg.grad = fft_rest.grad;</div><div style="font-size:14px">cfg.vol = vol; % head model</div><div style="font-size:14px">cfg.grid = grid; % source model</div><div style="font-size:14px">cfg.keeptrials = 'yes';</div><div style="font-size:14px">cfg.normalize = 'yes'; </div><div style="font-size:14px">cfg.channel = {'MEG'};</div><div style="font-size:14px">rest_grid = ft_prepare_leadfield(cfg);</div><div style="font-size:14px"><br></div><div style="font-size:14px">%% Source analysis </div><div style="font-size:14px">cfg = [];</div><div style="font-size:14px">cfg.frequency = 'all';</div><div style="font-size:14px">cfg.grad = fft_rest.grad;</div><div style="font-size:14px">cfg.method = 'dics';</div><div style="font-size:14px">cfg.grid = rest_grid;</div><div style="font-size:14px">cfg.vol = vol;</div><div style="font-size:14px">cfg.keeptrials = 'yes';</div><div style="font-size:14px">cfg.keepfilter = 'yes';</div><div style="font-size:14px">cfg.dics.lambda = 0;</div><div style="font-size:14px">cfg.dics.projectnoise = 'yes';</div><div style="font-size:14px">rest_source = ft_sourceanalysis(cfg, fft_rest);</div><div style="font-size:14px"><br></div><div style="font-size:14px">mri_slice = ft_volumereslice([], mri) %mri: volumesegmented mri</div><div style="font-size:14px">cfg = [];</div><div style="font-size:14px">cfg.parameter = 'avg.pow';</div><div style="font-size:14px">rest_sointer = ft_sourceinterpolate(cfg, rest_source, mri_slice);</div><div style="font-size:14px"><br></div><div style="font-size:14px"><br></div><div style="font-size:14px"><b>Q2. Is there any way to check whether the beamforming is performed well?</b></div><div style="font-size:14px"><br></div><div style="font-size:14px">Any help would be greatly appreciated.</div><div style="font-size:14px"><br></div><div style="font-size:14px">MK CHOE</div><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div><font color="#888888">Mi Kyung CHOE</font></div><span style="color:rgb(136,136,136)">Department of Brain & Cognitive Sciences, </span><span style="color:rgb(136,136,136)">Seoul National University </span><div><font color="#888888">Human Brain Function Laboratory<br></font><div><font color="#888888">E-mail : <a href="mailto:cmk0803@hbf.re.kr" target="_blank">cmk0803@hbf.re.kr</a>, <a href="mailto:cmk0803@meg.re.kr" target="_blank">cmk0803@meg.re.kr</a></font></div></div></div></div>
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