[FieldTrip] plotting differences in power spectrum

[McConnell, Keith]

Hello,

I have an MEG experiment in which I expect my stimulus to incite multiple reactions.  I have run the experiment so that the stimulus is applied at two different intensities.  I would like to use the lower intensity stimulus response as a 'mask' for the higher intensity response.

I can calculate the power spectrum for both intensities and find the difference.

Although I can generate an ft_multiplot for each individual power spectrum, I cannot generate a  ft_multiplotTFR of the difference between the two spectra.

I get the following error messages:

Error using ft_checkdata (line 366)
This function requires freq data as input.

Error in ft_multiplotTFR (line 135)
data = ft_checkdata(data, 'datatype', 'freq');

Can anyone provide some help?

Thanks,

Keith

Keith McConnell, M.S.

513.636.0739 (desk)
513.504.9907 (cell)

Division of Pulmonary Medicine
Cincinnati Children's Hospital Medical Center
Cincinnati, OH  45229

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