[FieldTrip] fieldtrip question - help needed

[s.rombetto at cib.na.cnr.it]

Hello
yes I'm referring to the example script 'fixing a missing sensor'.  
Even if you consider the structure grad, you also load LABEL275.mat  
and GRAD275.mat, that is the layout in someway.

What I do is to process my data: I define trials and preprocess them.  
Then I use ft_rejectvisual to remove artifacts and noisy channels.
After this my data are ok, but I have some missing channels.
In order to solve the inverse problem, I'm using a software that needs  
all the channels....and this is the reason why I'm trying to "fix the  
missing sensor".

Sara

> Cara Sara,
>
> I am not sure whether I totally understand your question. Are you
> referring to the example script 'fixing a missing sensor'?
> When I look at it on our (renewed) wiki (still brings tears to my
> eyes), I don't see any mention of a layout.
>
> I agree with you that the example however can be made a bit more clear.
> This is my take on it, starting from the back of the pipeline:
>
> The 'fixing' algorithm replaces a 'dead' channel with the average
> signal recorded at its neighbours. In the current implementation, the
> description of the sensors and the data (=the grad-structure and the
> data.trial) which go into ft_channelrepair need to contain a full
> description of the sensor-array, including the faulty one. In other
> words, if your sensor array has 10 sensors, one of which you want to
> have repaired, the input to ft_channelrepair needs a data-structure
> containing data from the spatial location of those 10 sensors (this is
> in data.grad, and needed to determine which channels are the
> neighbours). For consistency, the time course of the faulty channel
> also needs to be there. The actual time courses of the faulty channel
> will not be used, and these can take any value. Depending on the
> hardware and recording protocol, a faulty channel is either present or
> not in the data. In the example script, the faulty channel was not even
> recorded, and this is the reason for the first part of the script: the
> creation of a dummy channel, initialized with 0's in order to make
> ft_channelrepair work. If, however, your dataset actually contains data
> on the faulty channel (which may look very noisy), you can skip the
> first part of the script, and directly go to the second part.
>
> Best wishes,
>
> Jan-Mathijs
>
>
> On Jan 13, 2011, at 4:09 PM, s.rombetto at cib.na.cnr.it wrote:
>
>> Hello
>> can anybody spend some more words on the chapter "Fixing a missing sensor"?
>> I'm trying to use it with a AtB (like ITAB-Chieti) device...but I
>> cannot understand how to use it. I've several troubles when I've to
>> declare the layout, since I don't have a layout file, but I construct
>> that starting from grad...
>> Do you have any hint for me?
>>
>> Sara Rombetto
>>
>>
>> -------------------------------------------
>> * Dott.ssa Sara Rombetto                   *
>> * Istituto di Cibernetica "E. Caianiello"  *
>> * Via Campi Flegrei, 34                    *
>> * 80078 Pozzuoli (NA)                      *
>> * Italy                                    *
>> * tel +390818675054                        *
>> * fax +390818675326                        *
>> -------------------------------------------
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>>
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>
> Dr. J.M. (Jan-Mathijs) Schoffelen
> Donders Institute for Brain, Cognition and Behaviour,
> Centre for Cognitive Neuroimaging,
> Radboud University Nijmegen, The Netherlands
> J.Schoffelen at donders.ru.nl
> Telephone: 0031-24-3614793
>
> _______________________________________________
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip



-------------------------------------------
* Dott.ssa Sara Rombetto                   *
* Istituto di Cibernetica "E. Caianiello"  *
* Via Campi Flegrei, 34                    *
* 80078 Pozzuoli (NA)                      *
* Italy                                    *
* tel +390818675054                        *
* fax +390818675326                        *
-------------------------------------------

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