Muse Monitor: what are the "Delta_TP9", and so on, values?



I am using Muse Monitor and I don’t totally understand what are the values in the “Delta_TP9”, “Delta_AF7”, etc., columns in the csv file.
Are these the PSD for each brainwave at each channel? (But I find it weird because the first column is time and usually the PSD is expressed according to the frequency…).

I hope someone will be able to help me.

Thank you.


If you click the “?” icon in Muse Monitor, you can read about this in the in app help, or you can view the same information online at by clicking on Technical Manual in the top menu.

Alpha, Beta, Gamma, Delta and Theta are brainwaves, the values for which are the Power Spectral Density for a specific frequency range. So for example, with Delta, that range is 1Hz to 4Hz. The higher the Delta number, the more brainwave activity you have between 1Hz and 4Hz at that point in time.

TP9, AF7, AF8 and TP10 are the four muse sensor locations. The naming comes from the standard 10-20 EEG system:



Thank you for replying.

I looked more into the absolute data for each brainwave and I noticed that the data changed only every 33 values (with a frequency recording of 256Hz).

So my questions are:
The absolute values are not really given in real time, right?
My thinking is that they are calculated on an interval of 33/256 seconds, is that so?

(I just want to make sure I understood well this all thing…).

Thank you.


That is correct. The RAW values are at ~256Hz (for the MU-02 model Muse), but the Interaxon API only calculates the absolute values at ~10Hz.

In the developer docs under available data, you can see the listed “transmission frequency” for each element.