Playing computer games can bring two players' emotional responses and brain activity into unison, researchers in Finland say. Scientists at the Helsinki Institute for Information Technology measured the activity of facial muscles and recorded brain signals of game players and found people go through similar emotions and display matching brainwaves when competing in a computer game. "It's well known that people who communicate face to face will start to imitate each other. People adopt each other's poses and gestures, much like infectious yawning," researcher Michiel Sovijarvi-Spape said. "What is less known is that the very physiology of interacting people shows a type of mimicry -- which we call synchrony or linkage." The research team varied the amount of competitiveness in the gaming situation: Players teamed up against the computer and then competed directly against each other. The more competitive the gaming gets, the more in sync are the emotional responses of the players, the researcher found, and the players often reported negative emotions associated with the linkage effect. "Although counterintuitive, the discovered effect increases as a game becomes more competitive," the researchers wrote in the open access journal PLoS ONE. "And the more competitive it gets, the more the players' positive emotions begin to reflect each other. All the while their experiences of negative emotions increase."