A new study looks deep inside the brain, where previous learning was reactivated during sleep, resulting in improved memory. Neuroscientists teamed up with clinicians to study the brain electrical activity in five of the center's patients in response to sounds administered by the research team as part of a learning exercise. While prior studies have used EEG recordings captured by electrodes on the head to measure memory processing during sleep, in this study electrical activity was recorded from inside the brain.