Dear Duncan,

The attached file should fix the problem if you put it in your SPM
folder. It comes down to the fact that your dataset contains sensor
location for one EEG electrode and this confused the code.

Best,

Vladimir

On Tue, Oct 12, 2010 at 6:12 PM, Astle, Duncan <[log in to unmask]> wrote:
> Thanks so much for your help.
>
> Attached is one of the problematic data sets.
>
> Thanks,
> Duncan
>
> _________________________________________________
> Dr. Duncan Astle,
> British Academy Research Fellow and University Lecturer,
> Department of Psychology,
> Royal Holloway,
> University of London.
>
> [log in to unmask]
>
> -----Original Message-----
> From: Vladimir Litvak [mailto:[log in to unmask]]
> Sent: 12 October 2010 17:25
> To: Astle, Duncan
> Subject: Re: [SPM] MEG invertion problem
>
> Send me one problematic mat file and I'll look at it tomorrow.
>
> Vladimir
>
> On Tue, Oct 12, 2010 at 4:37 PM, Astle, Duncan <[log in to unmask]> wrote:
>>
>>  I tried that. Re-doing the MRI, coreg and forward model, but I still get the same problem.
>>
>> It still asks me if I want to display the EEG or MEG and then goes on to crash.
>>
>> Any more suggestions?
>>
>> Thanks so much,
>> Duncan
>>
>> _________________________________________________
>> Dr. Duncan Astle,
>> British Academy Research Fellow and University Lecturer,
>> Department of Psychology,
>> Royal Holloway,
>> University of London.
>>
>> [log in to unmask]
>>
>> -----Original Message-----
>> From: Vladimir Litvak [mailto:[log in to unmask]]
>> Sent: 12 October 2010 16:15
>> To: Astle, Duncan
>> Cc: [log in to unmask]
>> Subject: Re: [SPM] MEG invertion problem
>>
>> Try re-doing all the 'template', 'coregistration', 'forward model'
>> steps on those problematic datasets AFTER marking the EEG channels as
>> bad.
>>
>> Vladimir
>>
>> On Tue, Oct 12, 2010 at 4:00 PM, Astle, Duncan <[log in to unmask]> wrote:
>>> Hi Vladimir,
>>>
>>> I tried that, and according to the channels list it certainly doesn't think that there are any EEG channels. However, when I try the inversion I still get this message:
>>>
>>> ??? Error using ==> spm_eeg_lgainmat at 32
>>> No good EEG channels were found.
>>>
>>> Error in ==> spm_eeg_invert at 182
>>>    [L D{i}] = spm_eeg_lgainmat(D{i});
>>>
>>> Error in ==> spm_eeg_invert_ui at 103
>>>        D                            = spm_eeg_invert(D);
>>>
>>> Error in ==> spm_eeg_inv_imag_api>Inverse_Callback at 94
>>> handles.D = spm_eeg_invert_ui(handles.D);
>>>
>>> Error in ==> spm_eeg_inv_imag_api at 53
>>>        feval(varargin{:}); % FEVAL switchyard
>>>
>>> ??? Error while evaluating uicontrol Callback
>>>
>>> Any ideas?
>>>
>>>
>>> Thanks
>>> Duncan
>>>
>>> _________________________________________________
>>> Dr. Duncan Astle,
>>> British Academy Research Fellow and University Lecturer,
>>> Department of Psychology,
>>> Royal Holloway,
>>> University of London.
>>>
>>> [log in to unmask]
>>>
>>> -----Original Message-----
>>> From: Vladimir Litvak [mailto:[log in to unmask]]
>>> Sent: 12 October 2010 15:42
>>> To: Astle, Duncan
>>> Cc: [log in to unmask]
>>> Subject: Re: [SPM] MEG invertion problem
>>>
>>> Dear Duncan,
>>>
>>> Changing the channel type to 'Other' should do the job. Just make sure
>>> that you save the dataset properly (either do save(D) in a script or
>>> press the 'Save' button in the GUI). If you change the channel type
>>> and you then open the dataset again in the reviewing tool there should
>>> not be any channels with 'EEG' type there.
>>>
>>> Vladimir
>>>
>>> On Tue, Oct 12, 2010 at 3:37 PM, Duncan Astle <[log in to unmask]> wrote:
>>>> Dear all......
>>>>
>>>> So I am attempting to do a group invertion with my MEG data. Everything seems to be working fine, apart from for 3 of the participants' data sets. For these I think it is trying to use the 'EEG channels' - but there arn't any, and ultimately the invertion fails. It thinks this because there was an one electrode marked as an EEG electrode.  I have tried changing the channel information, so that it is listed as 'other', but it still doesn't work.
>>>>
>>>> Could some one clever please help me find out why it thinks that there are EEG channels, and how to stop it. The other participants' data seem to work fine......
>>>>
>>>> Many thanks,
>>>> Duncan
>>>>
>>>
>>
>