Memory Scientists accidentally discovered a technique that could unlock how memory works while conducting an experimental brain surgery on an obese man to suppress his appetite, using the increasingly successful technique of deep-brain stimulation. The man's brain was being stimulated with an electric current sent through electrodes immersed into the brain. Far from losing appetite, the patient experienced a stirring in his memory. He vividly recollected a scene that took place 30 years earlier. More experiments found that his learning power enhanced dramatically when the brain was stimulated.

Scientists are now looking into how the technique can be applied to the treatment of patients with Alzheimer's disease, which affects 450,000 people in Britain alone. If successful, scientists hope that the new technique can provide a "pacemaker" for the brain.

Andres Lozano, a professor of neurosurgery at the Toronto Western Hospital, Ontario, who is leading the research, endorses that initial results are promising. This is the first time that electric stimulation of the brain has shown to improve memory. They were trying to increase the volume of the memory circuits by intensifying the activity of the brain, Professor Lozano said. Stimulation of memory circuits is more likely to be stored and retained.

The discovery came as a surprise to him and his team, Professor Lozano said. They had been trying to locate the point in the obese man’s brain that controls appetite. All other attempts to control his appetite had failed and brain surgery was the last resort. While the researchers were exploring the hypothalamus, the part of the brain associated with hunger, the man’s memory flooded back. He suddenly recalled a time he spent in a park with friends when he was around 20 years old. He could identify his old girlfriend and other people with identifiable clothes. However he could not decipher what they were saying.

Professor Lozano said that the discovery has wide implications. He is presently developing the technique as a treatment for depression.