VOA常速英语2008年-Study Finds Brain Stimulation May Improve Memor

Medical researchers in Canada say a brain stimulation¹ procedure used to treat people with Parkinson's and other diseases could help restore the memory of dementia patients. The researchers stumbled upon the discovery when the technique unexpectedly brought back detailed² memories in one patient. VOA's Alex Villarreal has more.

Surgeons at Toronto Western Hospital had hoped that delivering electrical signals to a brain area called the hypothalamus would regulate the appetite of a 50-year-old morbidly³ obese⁴ man.

The technique, called deep brain stimulation, uses a surgically-implanted device to shoot an electrical pulse into targeted areas of the brain while the patient remains⁵ conscious.

Dr. Ali Rezai, of the Cleveland Clinic, explains, "The language of the brain is electricity. By applying electrical currents we can actually shut down different parts of the brain or activate⁶ different parts of the brain."

But in the middle of the operation, something surprising happened. The patient suddenly experienced a flood of detailed memories from an incident decades before.

"He reported he was in a park, that he was with his friends, he recognized the people and he recognized what they were saying. As we increased the intensity⁷ of the stimulation, more of the details filled in," says Dr. Andres Lozano.

Later tests revealed the patient's memory improved while his brain was being stimulated⁸. And after three weeks of constant stimulation, he performed significantly higher on learning tests.

"This is the first time that this area of the brain has been implanted in that an effect on memory has been witnessed," Dr. Lozano said.

Deep brain stimulation is most commonly used to treat movement disorders⁹, such as Parkinson's disease, helping¹⁰ patients with severe tremors¹¹. It also can help victims of chronic¹² pain and depression.

With this new discovery, researchers are now testing the procedure as a way to restore memories in patients with Alzheimer's.