Brain Detects Happiness More Quickly Than
Sadness
June 18, 2009
Our brains get a first impression of people's overriding social signals after
seeing their faces for only 100 milliseconds (0.1 seconds). Whether this
impression is correct, however, is another question. Now an international group
of experts has carried out an in-depth study into how we process emotional
expressions, looking at the pattern of cerebral asymmetry in the perception of
positive and negative facial signals.
The researchers worked with 80 psychology students (65 women and 15 men) to
analyze the differences between their cerebral hemispheres using the
"divided visual field" technique, which is based on the anatomical
properties of the visual system.
"What is new about this study is that working in this way ensures that the
information is focused on one cerebral hemisphere or the other", J. Antonio
Aznar-Casanova, one of the authors of the study and a researcher at the
University of Barcelona (UB), tells SINC.
The results, published in the latest issue of the journal Laterality, show that
the right hemisphere performs better in processing emotions. "However, this
advantage appears to be more evident when it comes to processing happy and
surprised faces than sad or frightened ones", the researcher points out.
"Positive expressions, or expressions of approach, are perceived more
quickly and more precisely than negative, or withdrawal, ones. So happiness and
surprise are processed faster than sadness and fear", explains Aznar-Casanova.
The two faces of the brain
This research study adds to previous ones, which had revealed asymmetries in the
way the brain processes emotions, and enriches the international debate in
cognitive-emotional neuroscience in terms of how to define the exact way in
which human beings process these facial expressions.
People make deductions from the expressions on people's faces. "These
inferences can strongly influence election results or the sentences given in
trials, and have been studied before in fields such as criminology and the
pseudoscience of physiognomy", the neuroscientist tells SINC.
Two theories are currently "competing" to explain the pattern of
cerebral asymmetry in processing emotions. The older one postulates the
dominance of the right hemisphere in the processing of emotions, while the
second is based on the approach-withdrawal hypothesis, which holds that the
pattern of cerebral asymmetry depends upon the emotion in question, in other
words that each hemisphere is better at processing particular emotions (the
right, withdrawal, and the left, approach).
"Today there is scientific evidence in favour of both these theories, but
there is a certain consensus in favour of the lateralisation of emotional
processing predicted by the approach-withdrawal hypothesis", concludes
Aznar-Casanova.
Source: Plataforma SINC
Medical News Today: http://www.medicalnewstoday.com
Back to News