Remembering faces is often like a game of Guess Who. And neuroscientists have long thought that the tissues that make up this region of the brain stops growing fairly early in life. But a recent discovery is challenging this idea, Andy Coghlan reports for New Scientist. The study, published in the journal Science, suggests that the part of the brain in charge of facial recognition actually continues to develop until around age 30.
But the change wasn't an in increase in neurons, but rather an increase in connections between existing neurons, Jon Hamilton reports for NPR. "You can imagine a ten-foot by ten-foot garden, and it has some number of flowers in there," Jesse Gomez, a Stanford University neuroscience researcher and lead study author tells Hamilton. "The number of flowers isn't changing, but their stems and branches and leaves are getting more complex."
For the study, Gomez and his colleagues ran a series of MRI scans on 22 children between the ages of five and 12 and compared them to brain scans taken of 25 adults between ages 22 and 28. When they looked at the scans, a region at the base of the brain known as the fusiform gyrus (the region where facial recognition is processed) stood out. The amount of brain tissue in the region became about 12.6 percent more dense, while the rest of the brain remained more or less the same, Ian Sample reports for The Guardian.
While it’s still unclear exactly why the changes occur, it’s possible that it comes as a result of having to meet—and keep track of—an in creasing number of people the older you get.
"When you're a young child, you need to recognize your family and a handful of friends," Stanford University psychology professor Kalanit Grill-Spector, who worked on the study, tells Hamilton. "But by the time you've reached high school or college your social group has expanded to hundreds or even thousands of people."
Generally, most changes to the brain occur during specific times of life, such as adolescence and pregnancy, when connections between neurons are shifted and pruned. By studying how this part of the brain develops with age, Gomez hopes to learn more about the brains of people who have trouble recognizing faces into adulthood, as in the case of conditions like face blindness or autism, Coghlan reports. In the meantime, this discovery might help researchers understand more about the aging process—as well as just how we can keep track of all the people we meet over the course of our lives.