(Relaxnews)—Most of the time, watching someone else move causes a "mirroring" effect, researchers say—that is, the parts of the brain responsible for motor skills are activated by watching someone else in motion. But a team from the University of Southern California finds that your feelings about the person you're watching can actually affect this process and lead to "differential processing"—for example, you may believe an annoying person is moving more slowly than he or she actually is.
"We address the basic question of whether social factors influence our perception of simple actions," said co-author Lisa Aziz-Zadeh. "These results indicate that an abstract sense of group membership, and not only differences in physical appearance, can affect basic sensory-motor processing." In this study, the researchers controlled for race, age and gender, but they introduced a backstory that primed participants to dislike some of the people they were observing: half were presented as neo-Nazis, and half were presented as likeable and open-minded. All study participants in the study were Jewish men.
The researchers found that when subjects viewed someone they found unlikeable, a part of their brain that was otherwise activated in "mirroring"—the right ventral premotor cortex—had a different pattern of activity for unlikeable people as compared to the likable ones. But the difference was only noted when the annoying person was present in the room—there was no difference in brain activity when the subject watched videos of the people they disliked. "Even something as basic as how we process visual stimuli of a movement is modulated by social factors, such as our interpersonal relationships and social group membership," said Mona Sobhani, lead author of the paper. "These findings lend important support for the notion that social factors influence our perceptual processing." Past research has shown that race or physical similarity can influence brain processes, and we tend to have more empathy for people who look more like us. The new findings appeared last week in the journal PLoS ONE. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0046809