Described are methods and a device for determining a valid intrinsic alpha frequency. Described herein are methods and a device for determining the appropriate intrinsic alpha frequency (IAF) to be applied for neuro-EEG synchronization therapy using alternating magnetic fields to gently “tune” the brain and affect the mood, focus and cognition of subjects. Methods and a device described herein use an algorithm to quantitatively analyze EEG recordings to determine if recorded EEG frequencies are valid, and if necessary, requiring additional recordings and analysis until a valid EEG is found. Methods and devices described herein can be utilized to calculate the intrinsic frequency of other EEG bands, including the Theta, Beta Gamma and Delta bands.
