# [Eeglablist] Mean frequency for some frequency bands

Emmanuelle Renauld emmanuelle.renauld.1 at ulaval.ca
Fri Apr 26 13:30:30 PDT 2019

```Hello,

I was reading an article using the "mean frequency" and wasn't sure what it meant. I am used to see information on the alpha peak, but not the "alpha mean frequency".

I found one explanation here, and it happens to be published in my field of study (tDCS). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4893480/ (See the EEG Mean Frequency section in the Method). Is something like this already in EEGLAB? Would you have any idea how to use it? If I already have my spectrum and freqs, I guess something like this could work?

indx = find the index of my frequency range of interest
my_spectrum = spectrum(:, indx);
PSD_norm = my_spectrum./mean(my_spectrum, [], 2);  %for each electrode separatedly
mf = sum(  freqs .* PSD_norm , 2)  %2 => over the second dimension, result is mf for each electrode.

In this article, they use 0-100 Hz to find the mean frequency. However, here, they compute the mean frequency for each frequency band. https://www.ncbi.nlm.nih.gov/pubmed/14724047

Does this measure seem interesting to you, masters of EEG?