Dear Enrico,
There is no standard polhemus format. Different pieces of software that come
with polhemus devices can produce very different files. Furthermore, there
are differences between different labs as to how fiducials and channel
locations are measured and in what order. The coregistration function
expects a polhemus file of the kind used at FIL and it is not very
surprising that your polhemus file is not the same.
Regarding the second error, it seems you have a cell array where a matrix is
expected. Recheck your files. Sensors and fiducials should be just numerical
matrices.
There is a GUI you may find useful that can be invoked from Other/sensors
(it may not work on some Matlab versions; will definitely work on 7.1 under
Windows). It facilitates creating location and fiducial files and supports
several EEG location formats. Write me off list with an example (small) of
your SPM EEG file and your locations file if you have problems using the
GUI.
Best,
Vladimir
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On
Behalf Of Enrico Schulz
Sent: Wednesday, January 23, 2008 6:19 PM
To: [log in to unmask]
Subject: [SPM] EEG source localisation problem
Dear spm5 source localisation experts,
I tried to use the SPM5 implemented source localisation with an
individual 3D brain and individual Polhemus coordinates. Unfortunately,
I received a lot of error messages depending on which processing way I
used (GUI, batch file from help button and Rik Henson's batch).
I assume this has something to do with my polhemus files and my self
created sensor location and fiducial files. I did not find an
instruction for the required data format. Furthermore, I don't have a
headshape file that contains more data points than electrode positions
and fiducials.
Is anyone out there who can give me some support for an exact and
individual source localisation?
Thanks in advance,
Enrico
I got this error via GUI after importing the polhemus file:
??? Index exceeds matrix dimensions.
Error in ==> spm_eeg_inv_datareg at 225
sensors = sensors(sens,:);
Error in ==> spm_eeg_inv_datareg_ui at 143
D = spm_eeg_inv_datareg(D);
Error in ==> spm_eeg_inv_imag_api>DataReg_Callback at 86
handles.D = spm_eeg_inv_datareg_ui(handles.D);
Error in ==> spm_eeg_inv_imag_api>Reg2tem_Callback at 80
DataReg_Callback(hObject, eventdata, handles);
Error in ==> spm_eeg_inv_imag_api at 54
feval(varargin{:}); % FEVAL switchyard
??? Error while evaluating uicontrol Callback
This error message appears after using individual sensor location files
(without polhemus *.pol file):
??? Undefined function or method 'sum' for input arguments of type 'cell'.
Error in ==> mean at 29
y = sum(x)/size(x,dim);
Error in ==> spm_detrend at 33
y = x - ones(m,1)*mean(x);
Error in ==> spm_eeg_inv_datareg>spm_eeg_inv_rigidreg at 353
S = spm_detrend(data2');
Error in ==> spm_eeg_inv_datareg at 104
M1 = spm_eeg_inv_rigidreg(fid_mri', fid_eeg');
Error in ==> spm_eeg_inv_datareg_ui at 143
D = spm_eeg_inv_datareg(D);
Error in ==> spm_eeg_inv_imag_api>DataReg_Callback at 86
handles.D = spm_eeg_inv_datareg_ui(handles.D);
Error in ==> spm_eeg_inv_imag_api at 54
feval(varargin{:}); % FEVAL switchyard
??? Error while evaluating uicontrol Callback
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