Group membership and brain activity

Whether or not a person likes somebody else can affect their brain activity. This is according to new research published in the journal PLoS ONE, which showed an individual's perception of someone impacts how the brain processes their actions.

Investigators from the Brain and Creativity Institute at the University of Southern California Dornsife College of Letters, Arts and Sciences found activity linked to motor actions that lead to differential processing are impacted by whether a person is fond of someone else.

Lisa Aziz-Zadeh, Assistant Professor at the Brain and Creativity Institute and the Division of Occupational Science, noted the team wanted to see if social factors might influence perception of small actions.

Ms Aziz-Zadeh stated: "These results indicate that an abstract sense of group membership - and not only differences in physical appearance - can affect basic sensory-motor processing."

Mona Sobhani, a graduate student in neuroscience at the university, noted the findings show perceptual processing can be influenced by both interpersonal relationships and social group membership.

Professor Chris Frith, a Chartered Psychologist from the Institute of Neurology at University College London, comments:

"Similar results have been reported before. For example, a 2009 paper from the Journal of Neuroscience suggested that brain activity elicited by another's pain is much reduced if the 'other' is of a different race. 

"The novelty of this new study is that the effect is found even when the knowledge about who is in your in-group is based on verbal report rather than visible physical appearance.

"A similar effect has also been found, by Sheng and Han for pain since the missing neural response to the pain of someone of a different race returns if that person becomes part of your team."