Unlike Deep Brain Stimulation, in which electrodes are implanted into the brain and which has also shown promise for enhancing memory as well as for the treatment of depression, the Northwestern study involves a non-invasive method called Transcranial Magnetic Stimulation (TMS). This uses magnetic pulses to induce electrical activity in particular regions of the brain and has previously been shown to enhance the learning ability of rats and shown promise in the treatment of migraines.