St. Louis, Nov. 2, 1998 -- Faces you can name may be easier to remember than unknown faces because they activate more parts of the brain, a new study suggests. By imaging volunteers who were viewing famous or unfamiliar faces, the researchers concluded that patterns of brain activity depend on the type of information that is available for memorization.
"When you access both verbal and nonverbal information about an item such as a famous face, you get activation of both sides of the brain," says William M. Kelley, a graduate student at Washington University School of Medicine in St. Louis. "But if you can access only one type of information -- as in the case of an unfamiliar face, which provides only nonverbal cues -- you use only the right side of the brain." Kelley will present his findings Nov. 9 in Los Angeles at the annual meeting of the Society for Neuroscience.
Kelley works with Steven E. Petersen, Ph.D., professor of neurology, radiology and neurobiology. "You tend to remember things better when you have two ways to get the information into memory," Petersen says.
Using functional magnetic resonance imaging (fMRI), Kelley and Petersen previously compared the memorization of words, faces and namable objects such as frogs and ladders. The words activated a region in the left frontal lobe, whereas the unfamiliar faces activated a corresponding region on the right side of the brain. Namable objects activated both the right and left regions.
The researchers wanted to see whether these activation patterns depend on the type of material used or the type of information provided. So in the current study, they compared the two types of faces. They selected the famous ones by presenting pictures of people to 20 volunteers before the imaging study began. President Clinton, Princess Diana, David Letterman and Nancy Reagan were among the faces that were familiar to everyone in the group.
Kelley and Petersen then obtained fMRI images while nine other volunteers tried to memorize both the famous and unfamiliar faces for a subsequent test. The images showed that part of the right frontal lobe became active when the subjects viewed unfamiliar faces, as in the previous study. But famous faces activated both the right and left frontal lobes. In the subsequent memory test, the volunteers found it easier to remember having seen a face before if it was famous.
"These results suggest that activation patterns do not depend solely on the type of material used but rather reflect the types of information available for encoding such materials," says Kelley.
"It also suggests that it's a good idea to pay attention to someone's name as well as their face when you're introduced to them," Petersen adds.
Kelley will present his findings at 1:45 p.m. Pacific Time on Monday, Nov. 9, in Petree Hall D at the Los Angeles Convention Center.
The Charles A. Dana Foundation and Washington University's McDonnell Center for Higher Brain Function supported this research.