BEIJING, Nov. 8 (Xinhua) -- An international team of researchers has made an attempt to detect the changes in the brain network organization when one is in a romantic relationship.

Scientists have found that romantic love is a complex state similar to addiction. Both can make people undergo changes in the brain region controlling reward and motivation behaviors. But the related changes in brain connectivity networks are yet to be explained.

Researchers from China and the United States used functional magnetic resonance imaging (fMRI) to compare the whole-brain functional network organization in two groups of volunteers. The "in-love" group had 16 females currently in love and the "single" group consisted of 14 females who have never been in love or a romantic relationship.

The human brain is organized into segregated networks with strong within-network connections and relatively weaker between network connections. The "small-world" organization is thought to be essential for maintaining an energetically efficient system as the brain consumes about 20 percent of the body's energy.

Compared with the single group, the love group showed lower network segregation in their fMRI results.

Brain connectivity refers to the efficiency of information transfer through the neural network. The "in-love" group showed decreased connectivity in the left angular gyrus, a hub of neural networks involving self-processing. Lower connectivity in angular gyrus may indicate that people in love pay less attention to themselves and more to their lovers.

Meanwhile, the love group displayed increased connectivity in the left fusiform gyrus, which plays an essential role in face recognition and recognizing facial expressions. The increased connectivity in fusiform may indicate that people in love are more likely to engage in emotional-social processing, such as reading and understanding their lovers' facial expressions.

The study has been published in the journal Brain Imaging and Behavior.

According to the researchers, the findings provide the first evidence of love-related brain network organization changes and suggest similar but different brain network alterations between romantic love and addiction, providing new insights on the neural systems underlying romantic love.