<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Hai List,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I was trying to fit the dipole for MEG gradiometers data. I'm registering MEG and MRI by providing the x, y, z coordinates manually. I am getting the correct coregistered output. </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">For localizing the N35 ( at 35 ms) activity, I am using the dipole fitting. I am getting the position of the dipole but I do not see the dipole moment (in the code, source_planar.dip.mom=(0,0,0)).</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I have pasted the snippet below which is been used to fit the dipole. Can someone help me in rectifying the problem?</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Thank You</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">%% CO-REGISTER MR-IMAGE TO FIDUCIALS<br>cfg = [];<br>cfg.method = 'fiducial';<br>cfg.fiducial.nas=[x, y, z];<br>cfg.fiducial.lpa=[a, b, c];<br>cfg.fiducial.rpa=[l , m, n];<br>cfg.coordsys = 'neuromag';<br>mri_realigned_fiducials= ft_volumerealign(cfg, mri);<br><br><br>%% CO-REGISTER TO DIGITIZATION POINTS<br>meg='path\subject_ssep_avg_tsss.fif';<br>headshape = ft_read_headshape(meg);<br>cfg = [];<br>cfg.method              = 'headshape';<br>cfg.headshape.headshape = headshape;<br>cfg.coordsys            = 'neuromag';<br>mri_realigned_digitization_points = ft_volumerealign(cfg, mri_realigned_fiducials);<br><br>%% SEGMENT IMAGE INTO BRAIN, SKULL AND SCALP<br>cfg = []; %% initialize<br>cfg.output = {'brain' 'skull' 'scalp'};<br>mri_segmented = ft_volumesegment(cfg, mri_realigned_digitization_points);<br><br>%% CREATE BRAIN MESH<br><br>cfg = []; %% initialize<br>cfg.method = 'projectmesh';<br>cfg.tissue = 'brain';<br>cfg.numvertices = 5000;<br>brain_mesh = ft_prepare_mesh(cfg, mri_segmented);<br><br><br>%% CREATE HEADMODEL<br>cfg = []; %% initialize<br>cfg.method = 'singleshell';<br>headmodel = ft_prepare_headmodel(cfg, brain_mesh);<br><br>%% CREATE GRID WARPED TO STANDARD MNI BRAIN<br>cfg = []; %% initialize<br>cfg.grid.warpmni = 'yes';<br>cfg.grid.template = 'C:\Users\mca\Documents\MATLAB\fieldtrip-20181129\template\sourcemodel\standard_sourcemodel3d10mm.mat';<br>cfg.grid.nonlinear = 'yes';<br>cfg.grid.unit = 'mm';<br>cfg.mri = mri;<br>warped_grid = ft_prepare_sourcemodel(cfg)<br><br><br><br>%% CREATE LEADFIELD<br>cfg = []; %% initialize<br>cfg.channel = {'MEGGRAD'};<br>sensors = ft_read_sens((meg), 'senstype', 'meg');<br>cfg.grad = sensors;<br>cfg.grid = warped_grid;<br>cfg.headmodel = headmodel;<br>% cfg.normalize='yes';<br>leadfield = ft_prepare_leadfield(cfg);<br><br>%% source space<br>cfg = [];<br>cfg.dataset = meg;<br>cfg.continuous    = 'yes';<br>cfg.bpfilter      = 'no';<br>cfg.demean        = 'yes';<br>cfg.baselinewindow = [-inf 0];<br>cfg.bpfreq       = [1 100];<br>cfg.channel       = 'MEGGRAD';<br>cfg.precision     = 'single';<br>data_meg = ft_preprocessing(cfg);<br><br>%selecting the segment of time series after viewing butterfly plot<br>cfg = [];<br>cfg.toilim = [0.034 0.036];<br>data_post = ft_redefinetrial(cfg, data_meg);<br><br> %timelock analysis <br>cfg             = [];<br>cfg.channel     = 'MEGGRAD';<br>cfg.covariance='yes';<br>% tlck_pre = ft_timelockanalysis(cfg, data_pre);<br>tlck_post = ft_timelockanalysis(cfg, data_post);<br><br> <br>%% ECD<br><br>cfg = [];<br>cfg.resolution = 1;<br>mri_resliced = ft_volumereslice(cfg, mri_realigned_digitization_points);<br>mri_resliced_cm = ft_convert_units(mri_resliced, 'cm');<br><br>cfg = [];<br>cfg.latency = [0.035 0.036];<br>cfg.numdipoles =1;<br>% cfg.symmetry = 'x';<br>cfg.grid.resolution = 1;<br>cfg.grid.unit = 'cm';<br>cfg.gridsearch = 'yes';<br>cfg.headmodel = headmodel;<br>cfg.senstype = 'meg';</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"> cfg.channel = 'MEGGRAD';<br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">source_planar = ft_dipolefitting(cfg, tlck_post);<br><br><br><br>%%plotting the dipole<br>figure<br>hold on<br><br>ft_plot_dipole(source_planar.dip.pos(1,:), mean(source_planar.dip.mom(1:3,:),2), 'color', 'g')<br>pos = mean(source_planar.dip.pos,1);<br>ft_plot_slice(mri_resliced_cm.anatomy, 'transform', mri_resliced_cm.transform, 'location', pos, 'orientation', [1 0 0], 'resolution', 0.1)<br>ft_plot_slice(mri_resliced_cm.anatomy, 'transform', mri_resliced_cm.transform, 'location', pos, 'orientation', [0 1 0], 'resolution', 0.1)<br>ft_plot_slice(mri_resliced_cm.anatomy, 'transform', mri_resliced_cm.transform, 'location', pos, 'orientation', [0 0 1], 'resolution', 0.1)<br>ft_plot_crosshair(pos, 'color', [1 1 1]/2);<br>axis tight<br>axis off<br>view(12, -10)<br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div><br></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr">Thank You<div>Pooja Prabhu</div><div><br></div></div></div></div></div></div>