It may take many of us more than one encounter to recognize a person’s face. Usually, we stare at the center of a person’s nose rather than their eyes to recognize them. Although several fixation points are involved before a person can recognize the face of a person, facial recognition is still considered to be an inborn and often-practiced skill that isn’t completely understood. At the World Science Festival, RadioLab’s Robert Krulwich, demonstrated to audience members the different degrees to which we all struggle with face-recognition through an interactive quiz.

“10 celebrity faces will be flashed on the screen for 15 seconds each,” Krulwich told the audience in the video. The audience was instructed to write their best guess on the line in the piece of paper they were given. The test did not evaluate the participant’s ability to spell correctly or remember celebrity names exactly, but rather asked they provide a description of the famous person if they were unable to recall any other information.

Here are some of the faces the audience was asked to recognize:

Angelina Jolie
Angelina Jolie World Science Festival/
Barack Obama
President Barack Obama World Science Festival/
Johnny Depp
Johnny Depp World Science Festival/

While some people in the audience only recognized one or two celebrities, only 10 recognized every celebrity.

Most of us most likely stumbled on a few of these celebrity faces, but people with prosopagnosia — the inability to recognize a familiar face, differentiate between unknown faces, or tell the difference between a face or an object — would experience a much more difficult time. Approximately two percent of the world’s population suffers from prosopagnosia, which is one in every 50 people, according to Radiolab. People with prosopagnosia attain the condition via stroke, brain injury, or neurodegenerative diseases, although some people are also born with it. Those with the condition also use voice, clothing, and different physical traits to identify people.