Physiological responses to violent game events: Does it matter whose character you kill? J Matias Kivikangas, M.A. & Niklas Ravaja, Ph.D. CKIR, Helsinki School of Economics, Finland THE CENTER FOR KNOWLEDGE AND INNOVATION RESEARCH H E L S I N K I S C H O O L O F E C O N O M I C S

Previous studies have shown that different violent and nonviolent game events elicit differential phasic emotion-related psychophysiological responses –Ravaja, N., Saari, T., Salminen, M., Laarni, J., & Kallinen, K. (2006). Phasic emotional reactions to video game events: A psychophysiological investigation. Media Psychology, 8, –Ravaja, N., Turpeinen, M., Saari, T., Puttonen, S., & Keltikangas-Järvinen, L. (in revision). The Psychophysiology of James Bond: Phasic Emotional Responses to Violent Video Game Events. Emotion. Previous studies have also shown that the type of opponent (computer, stranger, friend) influences emotional responses as indexed by tonic psychophysiological measures (mean values during the game session) –Ravaja, N., Saari, T., Turpeinen, M., Laarni, J., Salminen, M., & Kivikangas, M. (2006). Spatial presence and emotions during video game playing: Does it matter with whom you play? Presence: Teleoperators and Virtual Environments, 15, A question arises: –Does it matter whose character you kill? –Do phasic emotion-related physiological responses to violent events differ as a function of opponent type (computer, stranger, friend)? Background

Participants Participants were 99 (51 male and 48 female) Finnish undergraduates, who ranged from 19 to 34 years of age (mean 23.8 years) Participants participated in the experiment in groups of three same-sex persons. In each of the 33 groups, two of the participants were friends who knew each other before and one was a person unknown to the others (i.e., a stranger). In the present study, we used only the self-report and physiological data collected from the 33 so-called main participants. Game Super Monkey Ball Jr. (Sega Corporation, Tokyo, Japan) and Duke Nukem Advance (Take 2 Interactive, Berkshire, UK). The games were played with the Nintendo Game Boy Advance console (Nintendo Co., Ltd., Kyoto, Japan). Design A 2 (Game: Super Monkey Ball Jr., Duke Nukem Advance)  3 (Opponent: computer, stranger, friend) within-subjects design was employed Methods

Physiological measures Facial electromyography (EMG) Provides a direct measure of the electrical activity associated with facial muscle contractions (an important form of emotional expression) –Zygomaticus major (cheek) muscle area »An index of Positive Affect (PA) –Orbicularis oculi (periocular) muscle area »An index of PA –Corrugator supercilii (brow) muscle area »An index of Negative Affect (NA) Electrodermal activity (EDA) –The primary psychophysiological index of arousal –As people experience arousal their sympathetic nervous system is activated, resulting in increased sweat gland activity and skin conductance Methods

Dimensional Model of Emotion

Game Events The exact onset times of predefined game events were determined by examining the played games, frame by frame, using V-ToolsPro 2.20 software. We scored four different game events: –The player’s character (own PC) wounded an opponent character (NPC/PC; Opponent Wounded) –The player’s character (own PC) killed an opponent character (NPC/PC; Opponent Killed) –The player’s character (own PC) was wounded by an opponent character (NPC/PC; Own PC Wounded) –The player’s character (own PC) was killed by an opponent character (NPC/PC; Own PC Killed) Methods

Data Analysis Mean values for the psychophysiological measures were derived for one 1-s epoch before each event (Second 1) and for six 1-s epochs after event onset (Seconds 2 to 7). The data were analyzed by the Linear Mixed Models procedure in SPSS with restricted maximum likelihood estimation and a first- order autoregressive covariance structure for the residuals. Event-related changes in physiological activity were tested using the following orthogonal contrasts: –Linear trend across seconds 1 to 7 (Contrast 1a) –Quadratic trend across seconds 1 to 7 (Contrast 1b) –Friend vs. Stranger × Linear Trend across Seconds 1 to 7 (Contrast 2a) –Friend vs. Stranger × Quadratic Trend across Seconds 1 to 7 (Contrast 2b) –Computer vs. Friend and Stranger × Linear Trend across Seconds 1 to 7 (Contrast 3a) –Computer vs. Friend and Stranger × Quadratic Trend across Seconds 1 to 7 (Contrast 3b) Methods

H1: The wounding and death of the player’s own character will elicit PA as indexed by increased zygomatic and orbicularis oculi EMG activity. Hypotheses and Results I Event: Own PC killedEvent: Own PC wounded Contrast 1b, p <.001 Contrast 1a, p <.001 Contrast 3a, p <.001

H2: Killing or wounding the PC of another human (friend or stranger) will elicit greater PA as indexed by zygomatic and orbicularis oculi EMG activity compared to killing or wounding a NPC. Hypotheses and Results II Event: Opponent KilledEvent: Opponent Wounded Contrast 3b, p <.001Contrast 3a, p <.001

H3: NA as indexed by corrugator EMG activity will increase in the order of killing or wounding a NPC < killing or wounding the PC of a stranger < killing or wounding the PC of a friend. Hypotheses and Results III Event: Opponent KilledEvent: Opponent Wounded Contrast 3b, p <.001 Contrast 2b, p <.001 Contrast 3a, p <.001 Contrast 2b, p <.05 Contrast 3a, p <.001

H4: Physiological arousal as indexed by EDA will increase in the order of killing or wounding a NPC < killing or wounding the PC of a stranger < killing or wounding the PC of a friend. H5: Physiological arousal as indexed by EDA will increase in the order of the player’s character is wounded or killed by a NPC < the player’s character is wounded or killed by the PC of a stranger < the player’s character is wounded or killed by the PC of a friend. Hypotheses and Results IV Event: Opponent Wounded Event: Own PC Wounded Contrast 3a, p <.001 Contrast 2a, p <.001 Contrast 3a, p <.001

Although counterintuitive, the wounding and death of the player’s own character elicits some aspect of PA Killing and wounding the PC of another human elicits both greater PA and NA compared to killing and wounding a NPC Arousal associated with all types of violent game events increases in the order of playing against a computer < playing against a stranger < playing against a friend Conclusions