Dear Stephan,

This is already implemented in the source extraction functionality
that you can access via batch. If you specify radius of 0 you will get
just one dipole, but this might not be a good idea as the signal you
are really interested in might be projected on a different dipole
because of the orientations. So I'd suggest to take some radius around
your location of interest.

Best,

Vladimir

On Tue, Jul 3, 2012 at 4:38 PM, Stephan Moratti <[log in to unmask]> wrote:

Hi everybody,

I have a question: I would like to reconstruct single trial time series of a

dipole location on my surface mesh that I have used before for source

reconstruction using MSP in SPM8.

I see in the code the following parameters but later get lost:

% inversion parameters

%--------------------------------------------------------------------------

J    = model.inverse.J;                        % Trial average MAP estimate

T    = model.inverse.T;                        % temporal projector

U    = model.inverse.U;                        % spatial  projector[s]

Is   = model.inverse.Is;                       % Indices of ARD vertices

Ic   = model.inverse.Ic;                       % Indices of channels

It   = model.inverse.It;                       % Indices of time bins

pst  = model.inverse.pst;                      % peristimulus time (ms)

Nd   = model.inverse.Nd;                       % number of mesh dipoles

Nb   = size(T,1);                              % number of time bins

Nc   = size(U,1);                              % number of channels

Nw   = size(woi,1);                            % number of contrast windows

Nj   = numel(J);

So which of these matrices I would have to multiply with my single trial

data to reconstruct the time series of a specific dipole (mesh) location. If

I do J*T' I get the evoked response. Is there a kind of inverse operator

that can be multiplied with the single trial sensor data?

Thanks in advance,

Best,

Stephan

________________________________________________________

Stephan Moratti, PhD

see also: http://web.me.com/smoratti/

Universidad Complutense de Madrid

Facultad de Psicología

Departamento de Psicología Básica I

Campus de Somosaguas

28223 Pozuelo de Alarcón (Madrid)

Spain

and

Center for Biomedical Technology

Laboratory for Cognitive and Computational Neuroscience

Parque Científico y Tecnológico de la Universidad Politecnica de Madrid

Campus Montegancedo

28223 Pozuelo de Alarcón (Madrid)

Spain

email: [log in to unmask]

Tel.:    +34 679219982