Brain Feels Emotion From Both Sides
Jan. 15 -- In Leonardo da Vinci's famous portrait, Mona Lisa's slight smile appears on the left side of her face — the side controlled by the right side of her brain.
For years, scientists have argued that people process emotion in the right sides of their brains, and even the Mona Lisa seemed to support the idea. According to the theory, the emotion behind the mysterious smirk must stem from her right side since this hemisphere controls movement on the left.
But recent studies show it may not be all that simple.
Decoding What and How
It now appears that both the left and right sides of the brain are active as a person processes emotion — at least when it's expressed in language. Guy Vingerhoets, of Ghent University in Belgium, and colleagues recently demonstrated that while the brain's right hemisphere plays the dominant role in sensing the tone of an emotional message, the left hemisphere is important for decoding its meaning.
"When we pay attention to the what of the message (even when it's emotional), our left hemisphere is doing most of the work," Vingerhoets explained in an e-mail to ABCNEWS.com. "It appears that we have a different pattern of cerebral activity devoted to the emotional what and the emotional how of the spoken language."
The finding, which appeared in the journal, Neuropsychology, seems to agree with other work that has linked the brain's left hemisphere to language. The new research takes this further and shows that even when language expresses emotion, the brain's right hemisphere can't work alone, but depends on the left side to interpret the message.
Watching Blood Flow
To test the idea, Vingerhoets wired 36 people to a transcranial doppler ultrasonogram, an instrument that painlessly measures blood flow velocity to the brain's left and right middle cerebral arteries. The volunteers then listened to pre-recorded messages that contained various emotional meanings (happy, sad, angry or afraid).
They were asked to focus on either the actual meaning of the words or the emotional tone in which they were spoken. And the actors who read each sentence conveyed either an emotional or neutral tone.
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