Effects of Violent Versus Nonviolent Video Games on Children's Arousal, Aggressive Mood, and Positive Mood

This study investigated the relationship between violent video games and children's mood. A total of 71 children aged 8 to 12 years played a paper-and-pencil game, a nonviolent video game, and a violent video game. Results indicate that arousal, as measured by heart rate and self-reported arousal, increased significantly after playing the violent video game, as compared with the other two game conditions, with girls reporting more arousal than did boys. There was no significant increase in aggressive mood scores for either boys or girls after playing the violent game. Positive mood, as measured by positive affect, showed no significant increases or decreases after playing either video game. However, positive mood, as measured by general mood, showed a significant increase after playing the violent game for both boys and girls, but only as compared with the paper-and-pencil game. Results are interpreted in terms of social learning and cognitive information processing theories of aggression.     

He just wants to play: how goals determine the influence of violent computer games on aggression

Generally, the accessibility of goal-related constructs is inhibited upon goal fulfillment. In line with this notion, the current studies explored whether violent computer games may reduce relative accessibility of aggression if the game involves the fulfillment of an aggressive goal. Specifically, in Study 1, participants who watched a trailer for a violent computer game that fulfilled the goal of venting anger showed less relative accessibility of aggression compared to participants who watched the trailer without goal fulfillment. In Study 2, actually playing a violent computer game to vent anger also decreased the relative accessibility of aggression compared to a control condition in which the game was played without such a goal. Lastly, in Study 3, the relative accessibility of aggression was reduced after playing a violent computer game for participants who reported a high general tendency to vent their anger.     

Moderate psychosocial stress appears not to impair recall of words learned 4 weeks prior to stress exposure

Recent studies in humans have reported that recall of previously learned material is especially sensitive to the disruptive effects of pharmacologically induced cortisol elevations. Whether similar effects occur after exposure to psychosocial stress remains to be shown. Moreover it is unknown whether stress before or after the initial learning interacts with the later effects of repeated stress on delayed recall (e.g. state-dependent learning). Forty subjects participated in the present experiment. They learned a word list either one hour before or 10 min after exposure to a psychosocial laboratory stressor. Delayed recall was tested 4 weeks later, again either before or after stress. Salivary cortisol levels increased significantly in response to both stress exposures. Stress had no effects on the initial learning and also did not impair delayed recall. Moreover there was no evidence for state-dependent learning. The current data seem to be in conflict with previous studies demonstrating that delayed recall is especially sensitive to elevated cortisol levels. Several reasons for these discrepancies are discussed. Among them is the small sample size, the moderate cortisol increase in response to the second stress exposure but also the long recall delay, which might lead to memory traces less susceptible to stress.     

Violent computer games and their effects on state hostility and physiological arousal

An experimental study was conducted to investigate the impact of violent computer games on state hostility, state anxiety and arousal. Participants were undergraduate students, aged from 18 to 25 years. Before the experimental sessions, participants filled in self‐report measures concerning their video game habits and were also pre‐tested for aggressiveness and trait anxiety. Physiological responses (heart rate and skin conductance) were measured during the experiment. After playing, information about state hostility and state anxiety was collected. The results showed that participants who played the violent game reported significantly higher state hostility, and support the assumption that an aggressive personality moderates the effect of playing a violent game on state hostility. Aggr. Behav. 32:146–158. 2006 © 2006 Wiley‐Liss, Inc.     

Violent computer games and their effects on state hostility and Physiological arousal

An experimental study was conducted to investigate the impact of violent computer games on state hostility, state anxiety and arousal. Participants were undergraduate students, aged from 18 to 25 years old. Before the experimental sessions, participants filled in self‐report measures concerning their video game habits and were also pre‐tested for aggressiveness and trait anxiety. Physiological responses (heart rate and skin conductance) were measured during the experiment. After playing, information about state hostility and state anxiety was collected. The results showed that participants who played the violent game reported significantly higher state hostility and support the assumption that an aggressive personality moderates the effect of playing a violent game on state hostility. Aggr. Behav. 32:358–371. 2006. © 2006 Wiley‐Liss, Inc.     

Working memory performance after acute exposure to the cold pressor stress in healthy volunteers

Effects of acute stress exposure on learning and memory have been frequently studied in both animals and humans. However, only a few studies have focused specifically on working memory performance and the available data are equivocal. The present study examined working memory performance during the Sternberg item recognition task after exposure to a predominantly adrenergic stressor. Twenty four healthy subjects were randomly assigned to a stress group or a control group. The stress group was exposed to the cold pressor stress test (CPS; i.e. insertion of the dominant hand into ice water for 60s), while 37 °C warm water was used with the control group. Twenty minutes after the stress exposure, working memory performance was tested with the Sternberg item recognition task with three levels of cognitive load. Sympathetic nervous system and hypothalamic pituitary adrenocortical (HPA) axis activation during CPS, were assessed by measuring heart rate and salivary cortisol before and during (heart rate) or 30 min after (cortisol) the stress procedure. Exposure to the CPS test was associated with a significant increase in heart rate but no increase in salivary cortisol. Participants exposed to the stress procedure showed significantly shorter reaction times during trials with higher cognitive load but tended to show higher false alarm rates than control subjects. The present results indicate that exposure to CPS can be associated with signs of both enhanced and impaired working memory performance. The observed behavioral pattern might represent a form of streamlined information processing advantageous in a threatening situation.     

Effects of Playing Violent Computer Games on Emotional Desensitization and Aggressive Behavior1

This study analyzed the effects of playing a violent computer game on emotional desensitization and aggressive behavior. College students (N = 58) were randomly assigned to play a violent game (VG) or a nonviolent game (NVG), and then were exposed to a set of emotional pictures. Participants' physiological responses were recorded, and the Self‐Assessment Manikin scale was used to assess affective valence and arousal while viewing the pictures. Participants were then asked to replay the game, after which aggressive behavior was measured. Participants' violent game habits (VGH) were also measured. We found that VG playing interacted with participants' VGH to influence aggression, and that self‐reported valence mediated this effect by lowering the feelings of pleasure and displeasure toward emotional stimuli.     

Are the effects of Unreal violent video games pronounced when playing with a virtual reality system?

This study was conducted to analyze the short-term effects of violent electronic games, played with or without a virtual reality (VR) device, on the instigation of aggressive behavior. Physiological arousal (heart rate (HR)), priming of aggressive thoughts, and state hostility were also measured to test their possible mediation on the relationship between playing the violent game (VG) and aggression. The participants--148 undergraduate students--were randomly assigned to four treatment conditions: two groups played a violent computer game (Unreal Tournament), and the other two a non-violent game (Motocross Madness), half with a VR device and the remaining participants on the computer screen. In order to assess the game effects the following instruments were used: a BIOPAC System MP100 to measure HR, an Emotional Stroop task to analyze the priming of aggressive and fear thoughts, a self-report State Hostility Scale to measure hostility, and a competitive reaction-time task to assess aggressive behavior. The main results indicated that the violent computer game had effects on state hostility and aggression. Although no significant mediation effect could be detected, regression analyses showed an indirect effect of state hostility between playing a VG and aggression.     

The effects of cortisol increase on long-term memory retrieval during and after acute psychosocial stress

In this study the effects of stress-induced cortisol increases on long-term memory retrieval during and after acute psychosocial stress were examined. Seventy male students were exposed to either a psychosocial stress task or to a non-stressful control task. During and after this task, retrieval was tested for idiosyncratic emotionally negative and neutral word pair associations that were learned 1 day or 5 weeks earlier. Within the stress condition, retrieval of negative words, 5 weeks after learning, was impaired both during and after the stress task compared to the control group. Further, during the stress task, when sympathetic activity was enhanced, impaired retrieval of both neutral and emotional words was significantly related to enhanced cortisol response. In contrast, after the stress task, when cortisol levels were still increased but sympathetic activity was low again, no association was found between cortisol increase and retrieval of either neutral or emotional material. These results are in line with the previous animal research showing that when arousal is high, cortisol increase can impair memory retrieval.     

Experimental study of the differential effects of playing versus watching violent video games on children's aggressive behavior

There is great concern about the effects of playing violent video games on aggressive behavior. The present experimental study was aimed at investigating the differential effects of actively playing vs. passively watching the same violent video game on subsequent aggressive behavior. Fifty-seven children aged 10-13 either played a violent video game (active violent condition), watched the same violent video game (passive violent condition), or played a non-violent video game (active non-violent condition). Aggression was measured through peer nominations of real-life aggressive incidents during a free play session at school. After the active participation of actually playing the violent video game, boys behaved more aggressively than did the boys in the passive game condition. For girls, game condition was not related to aggression. These findings indicate that, specifically for boys, playing a violent video game should lead to more aggression than watching television violence.     

Acute stress impairs recognition for positive words--association with stress-induced cortisol secretion

Some studies suggest that stress-induced effects of cortisol on memory are modulated by the valence of the stimuli to be learned and retrieved. The present study investigated the effect of acute stress-induced cortisol secretion on acquisition and retrieval of pleasant, unpleasant and neutral words. Sixty healthy men were randomly assigned to one of the three experimental groups. Participants were either exposed to a standardized laboratory stressor (the Trier Social Stress Test) before learning a wordlist, or before retrieval, or were not stressed. Free recall and recognition were tested 24 h later. Free recall was not affected by stress exposure. For recognition, there was no main effect of the stressor, but a main effect of valence and a valence by group interaction emerged: recognition for positive words was significantly impaired when subjects were stressed before retrieval. In addition, a positive correlation between the cortisol response and errors of commission was found. The results suggest that acute stress impairs memory for positive stimuli and that stress-induced cortisol secretion interferes with accuracy of memory retrieval, i.e. the ability to discriminate true memories from false ones.     

The influence of violent and nonviolent computer games on implicit measures of aggressiveness

We examined the causal relationship between playing violent video games and increases in aggressiveness by using implicit measures of aggressiveness, which have become important for accurately predicting impulsive behavioral tendencies. Ninety‐six adults were randomly assigned to play one of three versions of a computer game that differed only with regard to game content (violent, peaceful, or abstract game), or to work on a reading task. In the games the environmental context, mouse gestures, and physiological arousal—as indicated by heart rate and skin conductance—were kept constant. In the violent game soldiers had to be shot, in the peaceful game sunflowers had to be watered, and the abstract game simply required clicking colored triangles. Five minutes of play did not alter trait aggressiveness, yet an Implicit Association Test detected a change in implicit aggressive self‐concept. Playing a violent game produced a significant increase in implicit aggressive self‐concept relative to playing a peaceful game. The well‐controlled study closes a gap in the research on the causality of the link between violence exposure in computer games and aggressiveness with specific regard to implicit measures. We discuss the significance of importing recent social–cognitive theory into aggression research and stress the need for further development of aggression‐related implicit measures. Aggr. Behav. 36:1–13, 2010. © 2009 Wiley‐Liss, Inc.     

Immersive Virtual Environments Versus Traditional Platforms: Effects of Violent and Nonviolent Video Game Play

An experiment focused on the effects of platform (desktop computer, immersive virtual environment; IVE), content (violent, nonviolent), and player gender on video game play outcomes. Results revealed an interaction such that participants reported higher levels of aggressive feelings when playing a violent video game in an IVE compared to violent game play on a desktop platform or nonviolent game play on either platform. Physiological results supported these findings. No gender effects were found, nor did platform intensify any effects for nonviolent game play. The findings suggest that the intensifying effects of IVEs for game play and aggression are content specific and provide further evidence that attention to playing platform is crucial in understanding violent video game effects.     

The effects of video game play on young children's aggression, fantasy, and prosocial behavior

From the ecological perspective of human development the emergence of significant media may affect children's behavior. It has been suggested that the home computer has the potential to affect young children's behavior, but no published data currently exist to support this hypothesis. However, home computer games have features similar to television. In that vein, research on television and aggression lends itself as a paradigm for studying the effects of video games on young children's behavior. From past television research it may be hypothesized that exposure to violent video games will increase children's aggressive behavior. Twenty-eight children, age 4 to 6 years were observed in a free play setting at baseline, after watching a violent cartoon and after playing “Space Invaders”. Results indicated significant differences in aggressive behavior, relative to baseline behaviors, after watching television and after playing video games. There was no difference between the television and video game conditions. It was concluded that violent video games arouse children in much the same way as violent television cartoons.     

Visuo-spatial path learning,stress, and cortisol secretion following military cadets’ first parachute jump: the effect of increasing task complexity

The present field experiment examined how multi-trial visuo-spatial learning and memory performance are impacted by excessive arousal, instigated by a potentially life-threatening event (i.e., a first parachute jump). Throughout a parachute training activity, subjective and neuroendocrine (i.e., cortisol) stress levels were assessed of 61 male military cadets who were randomly assigned to a control (n = 30) or a jump stress condition (n = 31). Post-stress learning and memory capacity was assessed with a 10-trial path-learning task that permitted emergence of learning curves. Pre-activity cortisol concentrations indicated a significant neuroendocrine anticipatory stress response in the stress group. Following parachuting, subjective stress levels and salivary cortisol reactivity differed significantly between groups. Visuo-spatial path-learning performance was impaired significantly after jump stress exposure, relative to the control group. Moreover, examination of the learning curves showed similar learning and memory performance at onset of the trials, with curves bifurcating as the task became more complex. These findings are in accordance with leading theories that acknowledge a moderating effect of task complexity. In sum, the present study extends knowledge concerning anticipatory stress effects, endogenously instigated cortisol reactivity, and the influence of extreme arousal on visuo-spatial path learning.     

Timing matters: Temporal dynamics of stress effects on memory retrieval

Stress may impair memory retrieval. This retrieval impairment has been attributed to the action of the stress hormone cortisol, which is released with a delay of several minutes after a stressful encounter. Hence, most studies tested memory retrieval 20–30 min after stress, when the stress-induced cortisol increase peaks. In the present experiment, we investigated whether retrieval impairments can also be found at later intervals after stress. To this end, participants learned a list of words on day 1. Twenty-four hours later, they were first exposed to a stressor or a nonstressful control manipulation and completed a recognition test for the words either immediately thereafter, 25 min later, or 90 min later. Our findings showed that stress did not impair memory retrieval when memory was tested immediately after the stressor, before cortisol levels were elevated. However, retrieval performance was impaired 25 min after stress, when cortisol levels peaked, as well as 90 min after the stressor, when cortisol levels had already returned to baseline. The retrieval impairment 90 min after stress appeared to be even stronger than the one after 25 min. These findings suggest that the detrimental effects of stress on retrieval performance may last longer than is usually assumed.     

The lone gamer: Social exclusion predicts violent video game preferences and fuels aggressive inclinations in adolescent players

Violent video game playing has been linked to a wide range of negative outcomes, especially in adolescents. In the present research, we focused on a potential determinant of adolescents’ willingness to play violent video games: social exclusion. We also tested whether exclusion can predict increased aggressiveness following violent video game playing. In two experiments, we predicted that exclusion could increase adolescents’ preferences for violent video games and interact with violent game playing fostering adolescents’ aggressive inclinations. In Study 1, 121 adolescents (aged 10–18 years) were randomly assigned to a manipulation of social exclusion. Then, they evaluated the violent content of nine different video games (violent, nonviolent, or prosocial) and reported their willingness to play each presented video game. The results showed that excluded participants expressed a greater willingness to play violent games than nonviolent or prosocial games. No such effect was found for included participants. In Study 2, both inclusionary status and video game contents were manipulated. After a manipulation of inclusionary status, 113 adolescents (aged 11–16 years) were randomly assigned to play either a violent or a nonviolent video game. Then, they were given an opportunity to express their aggressive inclinations toward the excluders. Results showed that excluded participants who played a violent game displayed the highest level of aggressive inclinations than participants who were assigned to the other experimental conditions. Overall, these findings suggest that exclusion increases preferences for violent games and that the combination of exclusion and violent game playing fuels aggressive inclinations.

     

Effects of stress and sex on acquisition and consolidation of human fear conditioning

We examined the relationship between stress hormone (cortisol) release and acquisition and consolidation of conditioned fear learning in healthy adults. Participants underwent acquisition of differential fear conditioning, and consolidation was assessed in a 24-h delayed extinction test. The acquisition phase was immediately followed by an 11-min psychosocial stress period (arithmetic test combined with a public speech). Salivary cortisol was sampled at various time points before and after acquisition and retention of fear conditioning. Results showed two effects of endogenous cortisol. Post-acquisition cortisol correlated with fear acquisition in male but not female participants. In addition, post-acquisition cortisol correlated with consolidation of fear but only in those participants with high cortisol levels. We conclude that in the short term, a robust and sexually dimorphic relationship exists between fear learning and stress hormone levels. For those participants whose fear learning is accompanied by high stress hormone levels, a long-term relationship exists between cortisol release and memory consolidation. These short-term and long-term effects may relate to the differential involvement of mineralocorticoid and glucocorticoid receptor subtypes, respectively. The findings have implications for understanding the role of stress, sex, and hormones in different stages of fear learning and memory.     

Violent Video Games Stress People Out and Make Them More Aggressive

It is well known that violent video games increase aggression, and that stress increases aggression. Many violent video games can be stressful because enemies are trying to kill players. The present study investigates whether violent games increase aggression by inducing stress in players. Stress was measured using cardiac coherence, defined as the synchronization of the rhythm of breathing to the rhythm of the heart. We predicted that cardiac coherence would mediate the link between exposure to violent video games and subsequent aggression. Specifically, we predicted that playing a violent video game would decrease cardiac coherence, and that cardiac coherence, in turn, would correlate negatively with aggression. Participants (N = 77) played a violent or nonviolent video game for 20 min. Cardiac coherence was measured before and during game play. After game play, participants had the opportunity to blast a confederate with loud noise through headphones during a reaction time task. The intensity and duration of noise blasts given to the confederate was used to measure aggression. As expected, violent video game players had lower cardiac coherence levels and higher aggression levels than did nonviolent game players. Cardiac coherence, in turn, was negatively related to aggression. This research offers another possible reason why violent games can increase aggression—by inducing stress. Cardiac coherence can be a useful tool to measure stress induced by violent video games. Cardiac coherence has several desirable methodological features as well: it is noninvasive, stable against environmental disturbances, relatively inexpensive, not subject to demand characteristics, and easy to use. Aggr. Behav. 39:64‐70, 2013. © 2012 Wiley Periodicals, Inc.     

Racing dragons and remembering aliens: Benefits of playing number and working memory games on kindergartners' numerical knowledge

Sources that contribute to variation in mathematical achievement include both numerical knowledge and general underlying cognitive processing abilities. The current study tested the benefits of tablet‐based training games that targeted each of these areas for improving the mathematical knowledge of kindergarten‐age children. We hypothesized that playing a number‐based game targeting numerical magnitude knowledge would improve children's broader numerical skills. We also hypothesized that the benefits of playing a working memory (WM) game would transfer to children's numerical knowledge given its important underlying role in mathematics achievement. Kindergarteners from diverse backgrounds (n = 148; 52% girls; M_age = 71.87 months) were randomly assigned to either play a number‐based game, a WM game, or a control game on a tablet for 10 sessions. Structural equation modeling was used to model children's learning gains in mathematics and WM across time. Overall, our results suggest that playing the number game improved kindergarten children's numerical knowledge at the latent level, and these improvements remained stable as assessed 1 month later. However, children in the WM group did not improve their numerical knowledge compared to children in the control condition. Playing both the number game and WM game improved children's WM at the latent level. Importantly, the WM group continued to improve their WM for at least a month after playing the games. The results demonstrate that computerized games that target both domain‐specific and domain‐general skills can benefit a broad range of kindergarten‐aged children.