[FieldTrip] Using ICA to filter data

[Rodolphe Nenert]

Im still afraid that the power of this analysis will be very low.
Maybe you can try an ICA on your fMRI data and try to correlate each
component with your EOG timecourse.

Rodolphe N.

On Thu, Jun 16, 2011 at 1:16 PM, frank at greenant.net
<fieldtrip at greenant.net>wrote:

> It's a bit of a unique experiment, we're trying to use an ECG machine
> to acquire EOG, so it's only a single output channel.
>
> i guess what I need is a temporal ICA rather than a spatial one...
>
> On 17/06/2011, at 2:48 AM, Rodolphe Nenert wrote:
>
> To summarize, the ICA will decompose your signal into as many components as
> Electrodes.
> Therefore, trying to decompose only one source is useless.
> Did you use a full net of electrodes into your MRI machine or only EOG
> electrodes?
>
> Hope this helps,
>
> Rodolphe N.
>
> On Thu, Jun 16, 2011 at 11:42 AM, frank at greenant.net <
> fieldtrip at greenant.net> wrote:
>
>> I am trying to use fieldtrip to filter EOG data obtained in an MRI.
>> I want to be able to spot the saccades in the samples and ideally measure
>> their onset at the
>> end of each trial.
>>
>> As you may guess, it's quite noisy and it's broad spectrum noise, despite
>> pre-filtering.
>>
>> Ideally, I would like to isolate the component that corresponds to the MRI
>> interference
>> and then filter this out.
>>
>> I have managed to import the data and can run ft_componentanalysis
>> but it fails with:
>>
>> runica() - data size (1,30720) too small
>>
>> My data is single channel, 40 epochs, each of 6 seconds (time locked to
>> stim onset but not saccade onset)
>> Is there a different method I should be using?
>>
>> I have posted some sample data and the current script (which reads in the
>> data and runs preprocessing) to the following urls:
>>
>> http://greenant.net/temp/1_2_MRI_2011-04-29%2016:19:33.mat
>> http://greenant.net/temp/EOG_analysis.m
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>
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