If somebody was reading this sentence aloud, your brain
would be able to interpret whether I was speaking in anger,
joy, relief, or sadness. That's because emotions in speech
leave distinct "signatures" in the brain of the
Now, for the first time, brain scans have now characterised
those patterns. The finding could help determine where in
the brain deficits in emotion processing occur in people with
psychiatric disorders such as schizophrenia.
Thomas Ethofer at the University Medical Center of Geneva,
Switzerland, and colleagues identified spatial signatures
of emotion in the primary auditory cortex (PAC) an
area of the temporal lobes at the side of the brain, which
is responsible for the sensation of sound.
This area is known to react more strongly to emotional vocalisations
than to neutral speech, but because this increase in activity
is similar for all emotions, scientists had been previously
unable to separate one mood from another by using scans.
To solve this problem, Ethofer scanned the brains of 22 subjects
using functional magnetic resonance imaging (fMRI) while they
listened to emotional speech, and combined this with a technique
called multivariate pattern analysis (MVPA) used to
identify patterns in brain activation.
Each subject listened to the pseudo-sentence "ne kalibam
sout molem", spoken by 10 actors and pronounced in five
different ways with anger, sadness, neutrality, relief
While previous methods analysed increased brain activity
at individual locations, Ethofer looked at overall patterns
of activity. "Consider the following analogy," he
says. "If you have a puzzle consisting of black and white
pieces, it is hard to say whether they belong to a picture
of a zebra or a checkerboard if you look at each piece in
isolation, but it becomes relatively easy if you put the pieces
Using MVPA, the team was able to match distinct patterns
of brain activity as different emotions were heard, and identify
which emotion was being heard from the other alternatives.
"Particularly novel is the discovery of a specialised
role of auditory cortex in the processing of distinct emotions
a nice indication that the auditory cortex is not just
sensory," says Nina Kraus, a neuroscientist at Northwestern
University in Evanston, Illinois.
Understanding the emotion of others is vital to our social
skills. These findings might help researchers unravel where
our emotional response goes wrong in various psychiatric disorders
such as depression and schizophrenia, as well as autism, say