[FieldTrip] l1l2 norm inverse solver in fieldtrip?

[Alexandre Gramfort]

Hi Robin,

the solver for inverse problem with L1/L2 prior as described in:

A Distributed Spatio-temporal EEG/MEG Inverse Solver

is not really tractable on real data. My recent work [1]
explains how to solve it more efficiently in a few seconds.

[1] http://www.ncbi.nlm.nih.gov/pubmed/22421459

This is what I implemented in mne-python:

http://martinos.org/mne/auto_examples/inverse/plot_mixed_norm_L21_inverse.html#example-inverse-plot-mixed-norm-l21-inverse-py

I have matlab code too but it's less optimized in terms of speed. If
you feel like porting
it into Fieldtrip that would be much appreciated. See this page that
deserves some updates:

http://embal.gforge.inria.fr/

If you're into these methods I invite you to have a look at the next
improvement using Time-Frequency transforms:

http://www.ncbi.nlm.nih.gov/pubmed/23291276

with demo code:

http://martinos.org/mne/auto_examples/inverse/plot_time_frequency_mixed_norm_inverse.html#example-inverse-plot-time-frequency-mixed-norm-inverse-py

This contribution explains how to correct for amplitude bias and take
care of loose orientation constraints when working with cortical
source spaces.

Best,
Alex

PS : sorry Robert for advertising mne on the fieldtrip mailing list ...

-- 
Alexandre Gramfort, PhD
Assistant Professor,
TSI, Telecom ParisTech,  CNRS LTCI
37-39 Rue Dareau, 75014 Paris, France
http://alexandre.gramfort.net
alexandre.gramfort at telecom-paristech.fr




On Fri, Feb 8, 2013 at 12:52 PM, Robin <robince at gmail.com> wrote:
> Hello,
>
> Having got through the preprocessing I am now investigating source
> reconstruction.
>
> The information on the web site is very useful. This tutorial page:
> http://fieldtrip.fcdonders.nl/tutorial/minimumnormestimate
>
> Refers to Ou, W., Hamalainen, M., Golland, P., 2008, A Distributed
> Spatio-temporal EEG/MEG Inverse Solver
>
> which looks interesting but I wondered if this method was actually
> implemented in fieldtrip (or elsewhere). When I look in
> minimumnormestimate.m this reference is not listed as one of the
> methods implemented. Is it available as a different named method?
>
> Thanks for any help.
>
> Robin
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