Computer agents versus avatars: Responses to interactive game characters controlled by a computer or other player

Computer and videogames often require that users interact with other characters on the screen that represent other real people or characters that are controlled by computer code running within the game, The difference between game play with other avatars (player-controlled characters) or agents (characters controlled by the computer) may influence the engagement a game player experiences. This study investigated the effects of agency (avatar versus agent) and the type of gaming activity (competition versus cooperation) on physiological arousal and subjective evaluation of play. A 2 (avatar, agent) x 2 (competition, cooperation) within-subject experiment was conducted (N=32). Players exhibited greater physiological arousal to otherwise identical interactions when other characters were introduced as an avatar rather than an agent. Furthermore, the co-player's source of agency interacted with the type of gaming activity. The results have implications for understanding how different forms of representation in virtual worlds and games will affect psychological responses in the contexts of entertainment, learning and the conduct of serious work. (C) 2009 Elsevier Ltd. All rights reserved.