Summary: Facial expression can cause problems when trying to tell unfamiliar faces apart, a new study reports.
Source: University of Bristol.
People’s faces change from moment to moment. Even over the course of a conversation with someone, changes are seen in their expressions and in the angle of their head.
Over time there are still further changes in appearance, such as if someone grows a beard, changes their hairstyle or loses weight. When we know someone we can still recognise them easily, despite these sorts of changes.
The story is different for unfamiliar faces; for example, studies have shown that we are generally very poor at matching together two pictures of the same face.
How our visual system manages to overcome the challenge of facial changes, enabling us to recognise people, is still largely unknown. This new study, published today in the journal i-Perception, shows how facial expressions can cause problems and difficulties in terms of telling unfamiliar faces apart.
Using an identification task, participants learned the identities of two actors from naturalistic (so-called ‘ambient’) face images taken from movies.
Training was either with neutral images or their expressive counterparts, perceived expressiveness having been determined experimentally.
Expressive training responses were slower and more erroneous than were neutral training responses.
When tested with novel images of the actors that varied in expressiveness, neutrally trained participants gave slower and less accurate responses to images of high compared to low expressiveness. These findings clearly demonstrate that facial expressions impede the processing and learning of facial identity.
Because this expression-dependence is consistent with a two part model of face processing, in which changeable facial aspects and identity are coded in a common framework, it suggests that expressions are a part of facial identity representation.
Lead researcher Annabelle Redfern, from the School of Experimental Psychology, said: “Our approach was to use several hundred pictures of faces taken from movies, which meant that the images in these experiments resemble the sorts of faces that we see every day.
“We measured people’s reaction times and their accuracy at telling unfamiliar faces apart, and how this differed when the faces were very expressive compared to when they had a neutral expression.
“The differences we found point to the idea that facial expressions and facial identity are not treated separately by our brains; and instead, we may mentally store someone’s expressions along with their faces.”
Source: Annabelle Redfern – University of Bristol
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Full open access research for “Expression Dependence in the Perception of Facial Identity” by Annabelle S. Redfern and Christopher P. Benton in iPerception. Published online June 1 2017 doi:10.1177/2041669517710663
[cbtabs][cbtab title=”MLA”]University of Bristol “Facial Expressions Can Cause Us Problems in Telling Unfamiliar Faces Apart.” NeuroscienceNews. NeuroscienceNews, 5 June 2017.
<https://neurosciencenews.com/facial-expression-recognition-6831/>.[/cbtab][cbtab title=”APA”]University of Bristol (2017, June 2). Facial Expressions Can Cause Us Problems in Telling Unfamiliar Faces Apart. NeuroscienceNew. Retrieved June 5, 2017 from https://neurosciencenews.com/facial-expression-recognition-6831/[/cbtab][cbtab title=”Chicago”]University of Bristol “Facial Expressions Can Cause Us Problems in Telling Unfamiliar Faces Apart.” https://neurosciencenews.com/facial-expression-recognition-6831/ (accessed June 5, 2017).[/cbtab][/cbtabs]
Abstract
Expression Dependence in the Perception of Facial Identity
We recognise familiar faces irrespective of their expression. This ability, crucial for social interactions, is a fundamental feature of face perception. We ask whether this constancy of facial identity may be compromised by changes in expression. This, in turn, addresses the issue of whether facial identity and expression are processed separately or interact. Using an identification task, participants learned the identities of two actors from naturalistic (so-called ambient) face images taken from movies. Training was either with neutral images or their expressive counterparts, perceived expressiveness having been determined experimentally. Expressive training responses were slower and more erroneous than neutral training responses. When tested with novel images of the actors that varied in expressiveness, neutrally trained participants gave slower and less accurate responses to images of high compared with low expressiveness. These findings clearly demonstrate that facial expressions impede the processing and learning of facial identity. Because this expression dependence is consistent with a late bifurcation model of face processing, in which changeable facial aspects and identity are coded in a common framework, it suggests that expressions are a part of facial identity representation.
“Expression Dependence in the Perception of Facial Identity” by Annabelle S. Redfern and Christopher P. Benton in iPerception. Published online June 1 2017 doi:10.1177/2041669517710663
