Units of source estimates

Hi All,

Hoping this is an easy question for someone to answer, otherwise I can
answer it myself with the literature / source code: Which of the source
estimation techniques implemented in MNE-python return estimates of the
current amplitude?

For example, my understanding is that:
(1) MNE returns estimates in current amplitude Am/m^2
(2) dSPM and sLORETA return standardized estimates (arbitrary units?)

I would expect the sparse estimates to return current amplitudes, but I'm
not sure. What about beamformers?

Thanks,
Emily
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Sorry, I think the MNE estimates are in Am, not Am/m^2.

hi,

Hoping this is an easy question for someone to answer, otherwise I can

answer it myself with the literature / source code: Which of the source
estimation techniques implemented in MNE-python return estimates of the
current amplitude?

well it differs a lot between solvers and even options.

For example, my understanding is that:
(1) MNE returns estimates in current amplitude Am/m^2

it's in Am

(2) dSPM and sLORETA return standardized estimates (arbitrary units?)

it is MNE scaled by some standard deviation so it has no units. It's
comparable
to a T or and F statistic.

I would expect the sparse estimates to return current amplitudes, but I'm

not sure.

sparse solvers (TF-)MxNE family, gamma-MAP, MUSIC, single dipole fit returns
dipole amplitudes in Am.

What about beamformers?

it depends on the options. If you use something like the Neural Activation
Index (NAI)
to "normalize" LCMV solutions you also have quantities without units. I am
less an
expert on beamformer options but they won't return you Am.

HTH
Alex

Thanks,
Emily

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