It’s a problem many of us have encountered for the first time this year – the difficulty in identifying someone whose face is partially concealed by a mask.
Researchers from Israel’s Ben Gurion University (BGU) of the Negev investigated why exactly medical face masks make it so hard to identify even close friends.
The researchers found that masks reduce the success rate of identifying a person by 15% – and, crucially, slows down the process (which is normally instant).
Professor Tzvi Ganel, head of the Laboratory for Visual Perception and Action at the BGU Department of Psychology said: "For those of you who don't always recognise a friend or acquaintance wearing a mask, you are not alone.”
Watch: How to wear a face covering comfortably
The researchers wrote: “Faces are among the most informative and significant visual stimuli in human perception and play a unique role in communicative, social daily interactions.
“The unprecedented effort to minimise COVID-19 transmission has created a new dimension in facial recognition due to mask wearing.”
The researchers used a variant of the Cambridge Face Memory Test, a standard tool for assessing facial perception, in online tests with nearly 500 people.
The researchers found that wearing a mask led to errors in identifying people - including “false positives”.
“This could lead to many errors in correctly recognizing people we know, or alternatively, accidently recognising faces of unfamiliar people as people we know,” says Prof Galia Avidan who is a member of the BGU Department of Psychology and the Department of Cognitive and Brain Sciences, and an expert on facial recognition and perception.
“Face masks could be even more challenging to people whose face recognition skills are not ideal to begin with and cause greater impairment.”
The research team also found that masks specifically interfered with extracting a holistic impression of faces.
Instead, people resort to feature-by-feature processing which is less accurate and more time-consuming.
“Instead of looking at the entire face, we’re now forced to look at eyes, nose, cheeks, and other visible elements separately to construct an entire facial face percept – which we used to do instantly,” the researchers said.
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