Video games are one of the fastest growing forms of entertainment, and with the increasing competition in the industry, designing video games to be as enjoyable and entertaining as possible becomes a central goal for game developers. To be entertaining and enjoyable video games need to evoke some heightened level of emotional experience during play. With this heightened emotional experience comes the experience of being immersed in the game environment so that the player’s attention is fully on the game and he/she is not easily distracted from gaming. This immersion and enjoyment isn’t just a function of positive emotion. In fact, a common emotional experience in role playing, action and many other types of games is the build up of tension and negative emotion during challenge that is followed by a positive emotional spike when the challenge is overcome. Different game genre will have different goals for the player’s emotional experience, and varying emotional profiles that include both positive and negative emotion. Maximizing the emotional power of a game during its development cycle requires ongoing feedback about the emotional experience of players as they encounter the various features of the game. The challenge is in measuring the emotional experience of the player without interfering with the natural gaming experience. The player’s verbal report is not so informative about their moment to moment emotional experience so physiological measures have been turned to. The best physiologic measure for tracking emotional valence is facial EMG.
In order to validate the usage of facial EMG for gaming, Hazlett (2006) conducted a study with 13 boys playing a car racing video game. Through video review positive and negative events during play were identified. It was found that the zygomaticus EMG was significantly greater during positive events as compared to negative events. Also, the corrugator muscle EMG was found to be significantly greater during negative events as compared to positive. This study demonstrated that positive and negative emotion can be measured in real time during video game play with facial EMG.
There are a number of interesting game development applications for facial EMG. The emotional profiling of games gives a useful evaluation of a game’s impact on a player, how compelling they find the game, how the game measures up to other games in its genre, and how the different elements of the game enhance or detract from the game’s approach to engaging the player. If there are weaknesses in the game, the moment to moment emotional profile can help pinpoint where those weaknesses lie. Individual elements of a game can be tested separately or compared to other variations so one can choose the variation that has the strongest emotional impact. This can be any element such as static visual scenes, music, characters, story etc. The elements don’t have to be finished versions, but it needs to be kept in mind that the more barebones something is the less of an impact it will have. That is why one would want to compare things that have the same level of finish to them. The causal mini-games that are becoming evermore present on phones and handhelds often depend on short simple experiences of fun for their addictive quality. Facial EMG is well-suited to measure the intensity of positive emotional bursts associated with this fun, and to allow comparisons amongst games and mini-games. In addition to entertainment games, biometric assessment can be useful with serious games. Gaming with facial EMG feedback to the tester can achieve the game’s objectives of providing the player with controlled immersion and active learning. The biometric assessment also becomes useful for quantifying the effectiveness of the game, and quantifying the emotional shifts and learning that are the objectives of the serious game.