"These tests also differentiate between recognizing a face and actually naming it, which can help identify the specific type of cognitive impairment a person has," said study author Tamar Gefen, of Northwestern University Feinberg School of Medicine in Chicago. (Agencies)
Gefen worked alongside Emily Rogalski, also with Northwestern University, for the research. For the study, 30 people with primary progressive aphasia, a type of early onset dementia that mainly affects language, and 27 people without dementia, all with an average age of 62 were given a test.
The test includes 20 famous faces printed in black and white, including John F Kennedy, Lucille Ball, Princess Diana, Martin Luther King, Jr and Elvis Presley. Participants were given points for each face they could name. If the subject could not name the face, he or she was asked to identify the famous person through description.
Participants gained more points by providing at least two relevant details about the person. The two groups also underwent MRI brain scans. Researchers found that the people who had early onset dementia performed significantly worse on the test, scoring an average of 79 percent in recognition of famous faces and 46 percent in naming the faces, compared to 97 percent in recognition and 93 percent on naming for those free of dementia.
The study also found that people who had trouble putting names to the faces were more likely to have a loss of brain tissue in the left temporal lobe of the brain, while those with trouble recognizing the faces had tissue loss on both sides of the temporal lobe.
"In addition to its practical value in helping us identify people with early dementia, this test also may help us understand how the brain works to remember and retrieve its knowledge of words and objects," Gefen said.
The research was published in Neurology, the medical journal of the American Academy of Neurology.
"These tests also differentiate between recognizing a face and actually naming it, which can help identify the specific type of cognitive impairment a person has," said study author Tamar Gefen, of Northwestern University Feinberg School of Medicine in Chicago.