The Daily Telegraph has a fascinating story about an accidental neurological discovery. While trying to “switch off” an obese man’s desire to overeat, neurologists using a brain stimulating device boosted his memory instead:
He had refused gastric surgery, and doctors decided deep brain stimulation of a structure linked with appetite called the hypothalamus. Electrodes are implanted in the brain under local anaesthesia, with the patient awake so their responses can be monitored.
The electrodes are stimulated by a “pacemaker” stitched into the chest. When the electrodes were stimulated by electrical impulses the patient began to experience feelings of deja vu.
He 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.
Prof Lozano says: “As we turned the current up, we first drove his memory circuits and improved his learning. As we increased the intensity of the current, we got spontaneous memories of discrete events.
“At a certain intensity, he would slash to the scene in the park. When the intensity was increased further, he got more detail but, when the current was turned off, it rapidly decayed.”
When the electrodes were stimulated for a second time, he experienced a similar effect. After three weeks of constant electrical stimulation the patient performed better in memory tests than he had previously done.