Do you ever find yourself living vicariously through other people? If so, researchers now say they can tell you which areas of the brain you're exerting when you experience that sort of empathetic connection with a stranger.

When we begin finding ourselves similar to other people and enjoying their victories as our own, researchers say that two particular regions of the brain responsible for feelings concerned with self and reward are talking to each other.

In a Brevium published 15 May in Science, Dean Mobbs from the Medical Research Council in Cambridge, UK muses on the fundamental issue: "Games shows are one of the most popular and enduring genres in television culture. Yet why we possess an inherent tendency to enjoy seeing unrelated strangers win in the absence of personal economic gain is unclear."

This question became the basis of his experiment, and along with colleagues from the University of Birmingham, the University College London, Aarhus University in Denmark, and the Consiglio Nazionale delle Ricerche in Cosenza, Italy, he describes how they used human volunteers and fMRI brain-imaging technology to pinpoint the areas of the brain associated with, first of all, perceiving someone else as similar to ourselves, and then feeling good about that person's accomplishments.

The team of researchers found that two particular regions of the brain - the ventral striatum and the ventral anterior cingulated cortex, or vACC - were responsible for this extension of our positive social behavior to unrelated strangers.

In order to reach these conclusions, they first had their volunteers watch two films of different people describing their personal, social, and ethical viewpoints in ways that the volunteer would find either agreeable or distasteful. Afterwards, the volunteers rated how similar they felt to the two people in those films with a survey.

Mobbs and his colleagues then monitored the brains of their volunteers with fMRI while they watched the same two people from the films - the one they felt similar to and the other that they did not agree with - compete in a game in which the winner was awarded cash prizes.

The researchers observed that, when the volunteer saw the person they felt most similar to win the game, their ventral striatum, which is known to be involved with the experience of reward or elation, became active. That same region of their brain was also active when the volunteers played the game and won for themselves.

Mobbs and his team also saw that a separate region of the brain, the vACC, which has been implicated in feelings that are relevant to the sense of self, was also active and positively correlated with the activity of the ventral striatum.

"Until now, studies of the neural representation of others' mental states have been concerned with negative emotions, like empathy for pain," Mobbs writes in his report. "Here, we show that similar mechanisms transfer to positive experiences such that observing a...contestant win increases both subjective and neural responses in vicarious reward. Such vicarious reward increases with perceived similarity and vACC activity... "

In light of these results, the researchers suggest that the vACC modulates positive feelings of self and then relays them to ventral striatum in order to express feelings of reward - even if we're actually only seeing our self in other people.