How to use data from Muse Monitor app, displaying or converting logarithmic data

csv
excel
graph
musemonitor

#1

Hello Muse Community,

I have been using the Muse device with the Muse Monitor App for android devices, and I have been exporting the data recordings into .csv files which I then open in Microsoft Excel. I am looking to track the mV values sampled from each Hz band (delta-gamma) throughout the recording.

My problem is that when I open these files and search under columns TP9, AF7, AF8, and TP10 of each frequency band, they values provided are logarithmic and provide no usable information regarding the absolute values recorded.

Has anyone dealt with this issue? Is it possible to make conclusions with my data in this logarithmic ratio form? Are there any applications or formulas I can use to convert these values back into an absolute value?


#2

@amatiasso, the logarithmic power spectral density (PSD) values as read from the Interaxon APIs are in the approximate {-1:+1} range, which is what you see in the Excel recording. In the Muse Monitor text value display these are shown in a more legible {0:100} range. This is purely to make it easier for the layman to understand. It is simply a linear translation: displayValue = (PSD + 1) * 50.

You can find information about this in the in app help by pressing the ‘?’ button, or in the online Technical Manual on the Muse Monitor website.


#3

Thank you so much for your timely reply.
I have converted the PSD values to match display values via the formula given above. So, the value I get after using this formula would be the AVG mV output for a given frequency band, correct?


#4

No, to quote the Interaxon documentation it is:

“the logarithm of the sum of the Power Spectral Density of the EEG data over that frequency range”