The technique involves implanting electrodes into the brain: in this case into an area in the limbic system called the hypothalamus, which is thought to control the appetite. When the electrodes were stimulated by electrical impulses the patient began to experience feelings of deja vu.

He then had a sudden perception of being in a park with friends. He felt younger, thought he was around 20-years-old, and his girlfriend of the time was there. He was an observer, and saw the scene in colour. As the intensity of the stimulation increased, details in the scene became more vivid.
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The results suggest it might be possible to use deep brain stimulation directly to boost memory. “We hopefully have found a circuit in the brain which can be modulated by stimulation, and which might provide benefit to patients with memory disorders,” said Professor Lozano. He is now leading a pilot study into whether deep brain stimulation can help people with early Alzheimer’s disease. They are initially testing six patients.