14 May 1999

Research on Alzheimer's Patients Offers Insight on Memory's Place in the Brain

It is well established that Alzheimer's Disease destroys memory. But a new study has found that the brain attempts to reorganize itself to compensate for that memory loss. The study was conducted at the Georgia State University.

Dr. John Woodard, from the University's Memory Assessment Clinic, tests the short-term memory ability of adults with Alzheimer's Disease using Positron Emission Tomography (PET). Research subjects underwent PET scans after rehearsing a set of words similar to a shopping list. By measuring blood flow within the brain using PET, Woodard demonstrates that the brains of Alzheimer's patients continue to use the same brain regions as older individuals without memory difficulties, and also recruit additional brain regions. The use of additional brain regions, presumably, compensates for the loss of other memory areas ravaged by the disease.

"Such a finding is important, since the frontal lobe of the brain has traditionally been associated with a very minor role in memory functioning. This study suggests that the frontal lobe plays a greater role in memory functioning than was previously thought," Woodard said.

Woodard used PET scans to track blood flow and neuronal activity in the brains of six AD patients and six people of the same age without memory difficulties. He found that the brains of Alzheimer's patients show a marked increase in activity in the frontal lobe when the patients were required to store and retrieve information such as lists of words.