Described herein, in certain embodiments, are devices and methods for modulating the electrical activity of a brain in a targeted manner using a weak magnetic field, generally field with a strength of less than about 100 Gauss. The magnetic field is varied over time in a periodic manner, generally with a frequency tuned to specifically affect one of the intrinsic frequencies of the brain, optionally the alpha frequency. The “Low Field Magnetic Stimulation” devices and methods described herein modulate the electrical activity of a brain without requiring medication. Methods and devices described herein gently “tune” the brain and affect mood, focus, and cognition of human subjects.
