Table 2.

Characteristics of each study included in the systematic review. Peracchia S, Curcio G.

References (Author, place)	AIMS	SAMPLE SIZE AND CHARACTERISTICS	VG USED	GROUPS CHARACTERISTICS	TIMING OF VG SESSION	TYPE OF SLEEP MEASUREMENTS
Higuchiet al.57	- To examine the effects of playing an exciting CG on pre/sleep physiological variables and sleepvariables. - To examine the exposure to a light by gazing at a bright display affects pre/sleep physiological variables and nocturnal sleep variables	6 male students (age 24.7 ± 5.6 ys)	CC: performed simple tasks with low mental load EC: Shooting game	Epidemiological studies. CC and EC group are the same	1:45 hours for each conditions	- EEG - Visual Analog Scale (VAS)
Dworaket al.51	To investigate the effects of singular excessive television and CG consumption on sleep patterns and memory performance of children	11 male children (age 13.45 ± 1.04 ys)	VG: - Need for Speed Most Wanted3 films: - Harry Potter and the Prisoner of Azkaban; - Star Trek; - Loves Music Loves to Dance	Randomized crossover trial. The participants adhered to their normal daily patterns but were not allowed to watch TV or play VG.	3 investigation days, session of 60 minutes of play	EEG
Ivarssonet al.69	To study cardiac, sleep-related, and emotional reactions to playing violent (VG) versus no/violent (NVG) VG in adolescents with different gaming habits	30 male adolescents (age range 13-16 ys)15 "high-exposed", and 15 "low-exposed"	ViolentVG :-Manhunt NonviolentVG: - Animaniacs	15 boys were thus used to play violent computer/VG at least 3 hours daily (''high-exposed''), and the other half used to play 1 hour or less daily (''low-exposed'')	NA	Sleep Diary
Weaveret al.46	- To investigate the capacity of pre/sleep VG play¬ing to extend sleep latency and reduce subjective feelings of sleepiness in adolescents - To investigate arousing psychophysiologic mechanisms involved and the impact of pre/sleep VG playing on sleep architecture	13 male adolescents (mean age 16.7 ys)	EC: - Call of Duty 4: Modern Warfare; - Infinity Ward CC: film: - March of the Penguins	Cross-sectional study. CC and EC group	Adolescents began to either play the VG (EC) or watch the film (CC), both for 50 minutes. Two experimental session, 1 week apart	- Sleep Diary - Stanford Sleepiness Scale - EEG - EOG
Brunettiet al.53	To examine the associations between screen (VG ,TV) and non screen (talking on the phone, doing homework, reading) sedentary time, and sleep in adolescents.	1859 children, of grade 5th (age 10.0 ± 0.5 ys ), 6th (11.7 ± 0.4 ys), 7th (12.9 ± 0.4 ys), 9th (15.2 ± 0.5 ys), and 11th (16.8 ± 0.5 ys). More than half (57%) of participants were female.	No VG	Cross-sectional survey. Only EC group	No VG	Questionnaires to evaluate: - Sleep duration, - Time spent daily in each of 6 sedentary behaviors screen activities (watching TV, using a computer, playing VG) and non screen activities (talking on the phone, doing homework, reading) - Daytime sleepiness
Van Den Bulck.49	To investigate the relationship between the presence of a TV set, a CG and/or an Internet connection in the room of adolescents and TV viewing, CG playing, and Internet use on the one hand, and time to bed, time up, time spent in bed	2546 adolescents (54.2% males), at first-year (mean age 13.16 ys) and fourth year (mean age 16.37 ys)	No VG	Prospective, uncontrolled observational study. Only EC group	No VG	Questionnaires to evaluate: - Sleep duration - Daytime sleepiness
Kinget al.52	To investigate the short term impact of adolescents' prolonged exposure to violent video-gaming on sleep.	17 male adolescents, (age 16±1 ys)	Warhammer 40.000: Space Marine	Experimental study. Adolescents were required to be "regular" VG players	Subjects were exposed to either 50 (regular) or 150 min (prolonged) of video-gaming directly before bedtime. Two testing nights, 1 week apart	- Sleep Diary - EEG
Ivarssonet al.48	To investigate how playing a violent/no/violet television game during the evening affects sympathetic and parasympathetic reactions during and after playing as well as sleep quality during the night after playing.	19 male adolescents (age 13.3± 0.7 ys; range 12–15 ys)	Violent VG: Manhunt Nonviolent VG: - Animaniacs	Experimental study. Violent and Non violent group	Two experimental sessions in their homes and one session without gaming	Sleep Diary
Wolfeet al.47	To look at the impact of video/gaming on daytime functioning by testing a mediation model using objective measures of video-gaming, sleep and performance in a controlled laboratory environment	21 adolescents (16 males) (age 17.6±1.8 ys; range 15-20 ys)	Bioshock Infinite	Cross-sectional survey. Only EC group	No more than 5 hours	Actigraphic registration
Exelman & Van Den Bulck50	To investigate the association of VG volume with sleep quality in adults via face-to-face interviews using standardized questionnaires	844 adults (56.2% women(age 46.0±17.76 ys)	No VG	Cross-sectional survey. Only EC group	No VG	- Pittsburgh Sleep Quality Index (PSQI) - Fatigue Assessment Scale (FAS) - Bergen Insomnia Scale (BIS) - Bedtime and rise time
Twengeet al.54	- To determine whether the self-reported sleep duration of U.S. adolescents changed between 2009 and 2015 - To examine whether new media screen time might be responsible for changes in sleep	369,595 students in 8th, 10th, and 12th graders school grade (13, 15, 17 ys)	No VG	Cross-sectional survey. Only EC group	No VG	Survey on line to evaluate sleep duration
Arrona-Palacios56	To compare the effects of time spent on VG during nighttime before going to sleep on the sleep-wake cycle, daytime sleepiness, and chronotype	568 students (288 girls) (age 14.08±0.72 ys) 287 from morning shift; 281 from afternoon shift	No VG	Cross-sectional survey. Only EC group	No VG	- Sleep timing questionnaire - Morningness - Eveningness Questionnaire (MEQ) - Epworth Sleepiness Scale

NOTE: CG: Computer Game; CC: Control Condition; EC: Experimental Condition; NA: Not Assessed.