[Eeglablist] Analysis of TMS-induced harmonics in the EEG

[JULIANA CORLIER]

Dear list, 

I would like to get some expert advice on how to assess/quantify the presence of harmonics in the EEG. 
Notably, our lab is using EEG recordings during repetitive transcranial magnetic stimulation (TMS) and we would like to assess whether the stimulation at a certain frequency elicits an entrainment at the stimulation frequency but also at other frequencies.  

My first approach was to check for ‘ratios of frequencies’ that show activation in the time-frequecy domain post stimulation, but that turned out to be a more tricky than I have aniticipated. 
I was wondering if there is a proper approach to harmonics analysis?
One would think that engineers and signal processing experts outside of neurosciences deal all the time with that.

Any advice is much appreciated! 

Thank you!

Juliana Corlier