DiagnosticsBrain Takes Just 200 Milliseconds To Interpret Facial Expressions
Researchers at the University of Glasgow have discovered that it takes the
brain just
200 milliseconds to gather most of the information it needs from a facial
expression to determine a person"s emotional state.
The study, published May 20 in the open-access, peer-reviewed journal PLoS
ONE and led by Prof Phillipe Schyns, Director of the Centre for Cognitive
Neuroimaging within the Department of Psychology, showed that the brain
starts by looking at the eyes then zooming out to process the whole face
before zooming back in to examine specific diagnostic features - such as
eyes open wide in fear, or a smiling mouth.
The researchers believe the results show that facial expressions and the
ability to decipher them co-evolved in the brain.
Prof Schyns said: "Facial expressions and the interpretation of them are a
fundamental part of human communication and our study has revealed how the
brain uses facial details in order to make crucial social judgements."
"Our study suggests that facial expressions co-evolved with the brain -
the former to be deciphered, the latter to decipher. With time-resolved
brain data, we reveal both how the brain uses different expressive
features, and when it has processed enough information for the critical
social
judgements we take for granted, and all within 200 milliseconds."
There are six basic facial expressions: happiness, fear, surprise,
disgust, anger and sadness. All of these expressions have distinctive
characteristics between which the brain can easily distinguish.
Volunteers in the study were shown each expression on 10 different faces,
five male, five female, while brain-imaging equipment monitored how
quickly
different parts of the brain interpreted them.
The results showed that between 140-200ms of the picture being shown, an
information processing mechanism starts independently in both left and
right
brain hemispheres, looking first at the eyes, then the rest of the face
before zooming back in on specific features associated with the basic
emotions.
By the end of this process, the brain has enough information to predict
the emotional state of the person displaying the facial expression.
The study was funded by the BBSRC. The funders had no role in study
design, data collection and analysis, decision to publish, or preparation
of the
manuscript.
Citation:
"Transmission of Facial Expressions of Emotion Co-Evolved with Their Efficient Decoding in the Brain: Behavioral and Brain Evidence."
Schyns PG, Petro LS, Smith ML (2009)
PLoS ONE 4(5): e5625. doi:10.1371/journal.pone.0005625
Plos One