Objective: To study cardiac, sleep-related, and emotional reactions to playing violent (VG) versus nonviolent video games (NVG) in adolescents with different gaming habits.
Methods: Thirty boys (aged 13–16 years, standard deviation = 0.9), half of them low-exposed (≤1 h/d) and half high-exposed (≥3 h/d) to violent games, played a VG/NVG for 2 hours during two different evenings in their homes. Heart rate (HR) and HR variability were registered from before start until next morning. A questionnaire about emotional reactions was administered after gaming sessions and a sleep diary on the following mornings.
Results: During sleep, there were significant interaction effects between group and gaming condition for HR (means [standard errors] for low-exposed: NVG 63.8 [2.2] and VG 67.7 [2.4]; for high-exposed: NVG 65.5 [1.9] and VG 62.7 [1.9]; F(1,28) = 9.22, p = .005). There was also a significant interaction for sleep quality (low-exposed: NVG 4.3 [0.2] and VG 3.7 [0.3]); high-exposed: NVG 4.4 [0.2] and VG 4.4 [0.2]; F(1,28) = 3.51, p = .036, one sided), and sadness after playing (low-exposed: NVG 1.0 [0.0] and VG 1.4 [0.2]; high-exposed: NVG 1.2 [0.1] and VG 1.1 [0.1]; (F(1,27) = 6.29, p = .009, one sided).
Conclusions: Different combinations of the extent of (low versus high) previous VG and experimental exposure to a VG or an NVG are associated with different reaction patterns—physiologically, emotionally, and sleep related. Desensitizing effects or selection bias stand out as possible explanations.
From the Stress Research Institute (M.I., T.Å., F.L.) and Department of Psychology (M.I.), Stockholm University, Stockholm, Sweden; Departmentof Public Health Sciences (M.A.), Division of Occupational Medicine, Karolinska, Institutet, Solna, Sweden; Department of Clinical Physiology (M.A.), Södersjukhuset, Stockholm, Sweden; and Department of Neuroscience (F.L.), Child and Adolescent Psychiatry, Uppsala University, Uppsala, Sweden.
Address correspondence and reprint requests to Malena Ivarsson, BA, Stress Research Institute, Stockholm University, SE-106 91 Stockholm, Sweden. E-mail: firstname.lastname@example.org
Received for publication March 16, 2012; revision received December 20, 2012.