Loneliness Affects Brain Activity And Social Behavior

By Margarita Nahapetyan

Feelings of loneliness and social isolation can affect a human brain activity as well as people's behavior, shows a new study conducted at the University of Chicago.

Researchers have revealed over the time that loneliness leads to decreased activation of the ventral striatum. The ventral striatum is a region of the brain associated with rewards, and is activated through primary rewards such as food and secondary rewards such as money. Social rewards and feelings of love also may stimulate the region. According to the authors, one in five Americans experiences feelings of loneliness.

On the other side, experts have found that the temporoparietal junction, a region of the brain associated with taking the perspective of another person, is much less activated among lonely individuals compared with the ones that do not consider themselves as lonely.

"Given their feelings of social isolation, lonely individuals may be left to find relative comfort in nonsocial rewards," said John Cacioppo, the Tiffany and Margaret Blake Professor in Psychology at the University of Chicago. He presented the findings along with Jean Decety, the Irving B. Harris Professor in Psychology and Psychiatry at the University, at the annual meeting of the American Association for the Advancement of Science.

The study tested 23 female undergraduates in order to determine their extent of loneliness, using the fMRI (functional MRI) scanner. During MRI, the participants were shown pleasant photos of happy people and money as well as some unpleasant pictures and human conflict.

The researchers found that those participants who considered themselves as lonely showed less activity in their ventral striatum when shown pictures of people enjoying themselves. Additionally, the varying responses of all the participants have shown that loneliness played a role in the way their brain operates.

Jean Decety says, "The study raises the intriguing possibility that loneliness may result from reduced reward-related activity in the ventral striatum in response to social rewards," leading to speculation that activity in the ventral striatum may even promote feelings of loneliness.

The current study is the first one that used fMRI scans to measure activity in the brain in combination with data about social isolation, or loneliness. It is a new approach to psychology that can lead scientists to a better study of brain mechanisms and understanding the science of the brain.

Researchers wrote that by studying mechanisms of the brain, they hope to acquire new insights of mental activities which surround consciousness, perception and thought, through a realization of how columns of neurons stacked next to each other form elementary circuits to function as a unit. New visualization tools such as three-dimensional imaging will help scientists to develop a new way of studying psychology, they said.

"Psychological science in the 21st century can, and should, become not only the science of overt behavior, and not only the science of the mind, but also the science of the brain," concluded the experts.