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<span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">Dear Jo,</span>
<div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><br class="">
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<div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Have you plotted the 2 headshapes in a single figure, and likewise for the gradiometers? In other words, which of the 4 objects is off in terms of expected location in space?</div>
<div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Have you checked for the problematic subject, whether the order of the landmark-clicking in the polhemus procedure was consistent with how the coordinate system is defined?<br class="">
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<div class="">Best wishes,</div>
<div class="">JM</div>
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<blockquote type="cite" class="">
<div class="">On 19 Feb 2020, at 15:15, <a href="mailto:joachim.lange@med.uni-duesseldorf.de" class="">
joachim.lange@med.uni-duesseldorf.de</a> wrote:</div>
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Dear Fieldtrippers,<o:p class=""></o:p></div>
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I’m not sure whether my problem is a Fieldtrip or a Neuromag problem, but maybe someone can help me here.<o:p class=""></o:p></div>
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<o:p class=""> </o:p></div>
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I’ve recorded MEG data with a Neuromag system and the headshape and hpi coils using the polhemus system. When I read the headshape and the sensor locations from the fif-file and plot them using Fieldtrip, the plots look as expected, i.e., the “headshape” and
the hpi coils are located within the MEG sensors / helmet (see attached example figures S1_1 and S1_2 from different angles). For one subject, however, the sensors from the hdr.grad-file seem rotated and it even looks like the “headshape” is partly outside
the MEG sensors / helmet (see attached figures S2_1 and S2_2).<o:p class=""></o:p></div>
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I have no idea what is going wrong here and/or how I could correct the apparently wrong positions. Any help would be much appreciated.<o:p class=""></o:p></div>
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Thanks,<o:p class=""></o:p></div>
<div style="margin: 0cm 0cm 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">
Jo<o:p class=""></o:p></div>
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<o:p class=""> </o:p></div>
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Ps: the simple FT-code:<o:p class=""></o:p></div>
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<span class="Apple-converted-space"> </span><o:p class=""></o:p></div>
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hdr = ft_read_header(‘subject.fif’);<o:p class=""></o:p></div>
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headshape = ft_read_headshape(‘subject.fif’);<o:p class=""></o:p></div>
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figure;<span class="Apple-converted-space"> </span><o:p class=""></o:p></div>
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ft_plot_sens(hdr.grad, 'style', 'b.', 'coil', 'false');<span class="Apple-converted-space"> </span><o:p class=""></o:p></div>
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ft_plot_mesh(headshape.pos(1:4,:),'vertexsize',20,'vertexcolor','r'); %HPI coils<o:p class=""></o:p></div>
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ft_plot_mesh(headshape.pos(5:end,:),'vertexsize',20,'vertexcolor','k'); %”manual” headshape<o:p class=""></o:p></div>
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<span id="cid:89CCF4E1-C5DB-4D2F-8720-0A7FE6DB450C@dccn.nl"><S1_1.tif></span><span id="cid:FACD37CD-DC0C-404C-A316-32D7AEE18008@dccn.nl"><S1_2.tif></span><span id="cid:1061C95E-762F-40CC-B981-3507AD060845@dccn.nl"><S2_1.tif></span><span id="cid:3641AFC9-60D1-436B-A4F0-0146AEFBEEA9@dccn.nl"><S2_2.tif></span><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">_______________________________________________</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">fieldtrip
mailing list</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip" style="color: purple; text-decoration: underline; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class="">https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">
<a href="https://doi.org/10.1371/journal.pcbi.1002202" style="color: purple; text-decoration: underline; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class="">https://doi.org/10.1371/journal.pcbi.1002202</a></div>
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