Plotting power spectra of estimates on mne_analyze

✉️ Mailing List Archive (read-only)
1

Hi MNE users,

I want to plot on mne_analyze the power spectrum values of a set of
estimates obtained from a raw file. I got the estimates in matlab using
the forward matrix, the raw file and the noise covariance matrix but I
have not been able to create a file that mne_analyze can load and plot on
the cortex.

I understand mne_write_stc_file (although this one seems to be for time
domain files) or mne_write_w_file can help me but I am not sure how to use
them since I do not have a way to link channels and vertices.

Thank you very much for your help,

2

Hi Andres,

I'm not sure what you mean by "way to link channels and vertices."

This seems to suggest you created your power spectrum in sensor
space. Is this true?

If so what did you use the forward matrix for?

If you got the power spectrum values in source space (using some
inverse solution), then the solution to your problem is easy. Just
use one of the functions below to write those values to either a w
file or stc file.

Dan

3

Thank you Dan,

I got the power spectrum in source space (in matlab, after getting the
estimates).
My problem was that since I used matlab, I did not know which set of the
calculated power spectra belonged to either the left or the right group of
vertices (for left and right hemispheres).

It seems the first half of results belongs to the left hemisphere and the
second to the right one.
Is this correct?

Thanks for your comments,

-- Andr?s

Hi Andres,

I'm not sure what you mean by "way to link channels and vertices."

This seems to suggest you created your power spectrum in sensor
space. Is this true?

If so what did you use the forward matrix for?

If you got the power spectrum values in source space (using some inverse

solution), then the solution to your problem is easy. Just use one of
the functions below to write those values to either a w file or stc
file.

Dan

Hi MNE users,
I want to plot on mne_analyze the power spectrum values of a set of

estimates obtained from a raw file. I got the estimates in matlab
using

the forward matrix, the raw file and the noise covariance matrix but I

have not been able to create a file that mne_analyze can load and plot
on

4

Hi Andres, the structure,

raw = fiff_setup_read_raw()

contains the channel names in raw.info.ch_names

For agnostic labeling these names designate left hemisphere and
right hemisphere using 'lh' and 'rh'. For this case the first
half of the channels correspond to the left hemisphere and the
last half to the right hemisphere.

Best regards,

Kyle

5

Hi Andres,

if you are talking about the hemisphere of the vertices. This will
depend on your matlab scripts. You should specify and specifically
choose each hemisphere. I don't have the manual in front of me, but I
am sure there is a description of the forward matrix structure in it.
This will tell you exactly how to do what you want. I believe the
matlab section is chapter 10.

Dan

6

Thank you very much everybody for your comments and collaboration.
I was able to create the files.

Now, I have another question: How can I make visible the stc files in
mne_analyze?

After loading a surface in mne_analyze I load the stc file in Managing
overlays. After selecting the file I do not see any data on the surface or
any way to set a threshold to see my results.

What should I do in order to visualize the data?

Thanks very much for any comments on this regard,

-- Andr?s