By Bruce Bower, Science News
Youth is wasted on the young, but not so for face memory. In an unexpected discovery, people remember unfamiliar faces best between ages 30 and 34, scientists report in an upcoming issue of Cognition.
Many researchers think word skills, memory and other mental functions crest in the early 20s, as the brain attains full maturity. Consistent with that assumption, memory for names and for upside-down faces—a task that requires recognition of general visual patterns—hits a high point at ages 23 to 24, says a team led by psychology graduate student Laura Germine of Harvard University.
But in an unanticipated twist, face learning takes about a decade longer to be the best it can be, the researchers find in online experiments conducted with 44,680 volunteers, ages 10 to 70.
“Specialized face-processing in the brain may require an extended period of visual tuning during early adulthood to help individuals learn and recognize lots of different faces,” Germine says.
Although researchers have not previously looked for late-developing face memory, the new findings fit with evidence that a brain structure critical for face recognition—the fusiform gyrus—undergoes reorganization at least through young adulthood, comments psychologist Isabel Gauthier of Vanderbilt University in Nashville. Gauthier hypothesizes that this brain area underlies all sorts of visual expertise, with face recognition as its most prominent achievement (SN: 7/7/01, p. 10).
“What is somewhat surprising is that there is still room for improvement after years of learning faces,” Gauthier says.
It’s not clear why it should take at least 30 years to refine a person’s ability to remember new faces, remarks psychologist Catherine Mondloch of Brock University in St. Catharines, Canada. Facial features change during adolescence, so improvements in face memory among teens make sense, she notes. Perhaps additional enhancements occur as young adults enter the workplace and encounter increasing numbers of adult faces, Mondloch proposes.
Germine and her colleagues created an online face-recognition test, using six computer-generated faces of young, adult white males as targets. Participants first saw three differently aligned images of a target face, with each image shown for three seconds. They then viewed a lineup showing the target face and two other male faces posed in a new direction, and tried to pick the target.
After repeating this test for all six target faces, participants tried to identify target faces in 54 more lineups, with faces shown in novel views and under various lighting conditions.
Face recognition improved sharply on this test from age 10 to 20. Performance increased at a slower pace after age 20, reaching a zenith of 83 percent correct responses for study volunteers between ages 30 and 34. On average, 16-year-olds remembered faces about as well as 65-year-olds did, picking a previously seen face three-quarters of the time.
Germine’s group replicated these results in tests of memory for 10 white adult female faces and 10 white boys’ and girls’ faces. Males and females alike displayed the best face memory in their early 30s.
The researchers can’t exclude the possibility that a larger proportion of volunteers in their early 30s were white or were parents of young children, factors that would probably have upped their overall memory scores for faces of white adults and children. No data on participants’ race, ethnicity or families were collected.
On two other memory tests—involving recognition of 12 men’s names and 10 upside-down children’s faces, viewed briefly on a computer screen—top scores gravitated around 76 percent from ages 20 to 30, with an uptick at ages 23 to 24.
Scientists now need to track individuals from childhood to adulthood to confirm that face memory hits its prime shortly after age 30, Germine says.