Anger is an acute emotional-physiological reaction that ranges from mild irritation to intense fury and rage (i.e., state anger). The disposition to experience state anger with greater frequency and intensity is referred to as trait anger [1
]. When anger is not controlled or regulated appropriately, it increases the risk of aggressive behavior [3
]. Aggressive behavior is defined as any behavior directed to another person, object, or animal with the intention to cause harm and can be divided into in an impulsive and a deliberate subtype [6
]. Episodes of increased anger and aggression are common to all individuals; however, when such episodes occur frequently and increase in severity, they can create substantial personal and social problems [8
Anger regulation difficulties might increase the likelihood of aggression by increasing negative affect and physiological arousal, by reducing aggression inhibitions, compromising decision making processes, increasing difficulties in resolving difficult situations, and by diminishing the quality of interpersonal relationships (for a review, see [9
]). Anger regulation problems may, therefore, be an important underlying contributing factor to engage in aggressive acts. This especially might account for a specific subtype of aggressive behavior: reactive aggression. Reactive aggression is defined as impulsive, angry or defensive responses to threat, frustration or provocation [10
]. Importantly, reactive aggression is also referred to as affective aggression, i.e., spontaneous and emotionally driven forms of aggressive behavior [11
]. Especially in these cases, individuals experience difficulties in regulating aggressive impulses.
In treating aggression regulation problems, interventions based on principles of Cognitive-Behavioral Therapy (CBT) have traditionally been the interventions of first choice [12
]. CBT-based interventions, however, are only partially successful in reducing aggressive behavior and usually only beneficial to a subgroup of individuals [12
]. One limitation of CBT-based interventions is that they appeal to abilities for self-reflection and willingness to genuinely talk about problems in controlling anger and/or aggression. However, both these abilities and this willingness are often low among individuals with anger or aggression regulation problems (e.g., [16
]). Additionally, CBT-based interventions target more conscious, deliberate responses and thus may have little impact on underlying implicit or automatic characteristics [18
]. When left untreated, these underlying factors might re-emerge during highly provoking and frustrating situations [19
]. As such, there is room for alternative approaches to aggression regulation.
One such alternative approach focuses on the motivational underpinnings of anger regulation [20
]. People high (versus low) in trait anger tend to have high approach motivation [21
] especially in situations when they are socially provoked [22
]. Approach motivation is defined as the impulse to go toward [23
]. This tendency to approach potential social threats may be an important driver of heightened hostility and aggression. It even has been suggested that approach motivation determines whether trait anger becomes translated into state anger and aggression [24
]. The results of multiple studies showed that higher levels of trait anger predicted more aggression when a high approach-oriented posture (leaning forward) was assumed [24
]. Moreover, conditions that hinder approach behavior—like leaning backward and ambient darkness—have been found to lower state anger and aggression among people with high (rather than low) trait anger [25
]. The latter findings suggests that changing people’s motivational orientation may contribute to the regulation of anger and aggression regulation among high-risk populations.
A recent set of laboratory experiments examined whether the motivational approach to anger management can be turned into a training [26
]. These experiments made use of an adapted joystick task that was validated in previous motivational intervention research in the domains of treating alcohol abuse [27
] and social anxiety problems [29
]. The latter studies already proved that such an approach bias modification was successful in reducing alcohol consumption in heavy drinkers and emotional vulnerability in socially anxious individuals. In the experiments by [26
], healthy participants were asked to perform a task in which they responded to angry or happy faces with a joystick. In the avoidance training condition, participants made avoidance movements to angry faces. In the control condition, participants made approach movements to angry faces. The results showed that after avoidance training, participants reported less angry feelings and expressed less aggressive impulses. The latter was most evident among individuals high in trait anger. These results suggest that reducing approach motivation towards social threatening stimuli could be an important addition to conventional anger and aggression regulation interventions.
Although the aforementioned findings are promising, they are limited in important ways. First, the avoidance training of [26
] consisted of a single session. To increase the long-term effects of the training, its effects should be examined across multiple sessions. Second, the avoidance training was investigated among healthy undergraduate students who were not characterized by severe levels of anger and/or aggressive behavior. To elucidate the clinical relevance of motivational training, its effects among clinical populations need to be investigated. Third and last, the avoidance training of [26
] used a joystick task that was not very engaging for participants, which could hamper implementation in clinical settings. Especially among individuals seeking treatment for anger and aggression regulation problems, treatment motivation is often lacking [16
]. To warrant sufficient treatment motivation, it would be desirable to develop a more engaging variant of the motivational training.
To increase treatment motivation, interventions that use serious gaming and virtual reality technology have been found to be highly effective [31
]. Serious games refer to games that, although fun and engaging, have training, education, or health improvement as their primary purpose [32
]. By introducing playful and interactive elements in an intervention, serious gaming may enhance the motivation of the target group [31
]. Virtual reality (VR), on the other hand, makes use of virtual environments to present digitally recreated real world activities to participants via non-immersive and immersive mediums which can be systematically manipulated to be relevant to patients’ problems [34
]. Moreover, within VR, participants are fully immersed in the virtual environment which often creates a sense of presence. The latter refers to the participants experience of the sensation of being elsewhere, i.e., the feeling of actually being psychically present in the (VR) environment [36
]. This sense of presence is affected by a variety of factors, such as interactions with avatars (i.e., VR characters). The advantages, therefore, are that VR gives the unique opportunity to investigate and treat underlying behavioral mechanisms in controlled experimental designs that nonetheless possess high ecological validity. Another advantage is that VR has the ability to induce emotions, such as higher levels of anger after provocative scenario’s [37
]. Taken these advantages together, it has been suggested that VR has the potential to improve psychiatric interventions (for a review, see [38
Initial studies of serious gaming and VR in psychiatric treatments have found that these techniques can be used to successfully reduce aggressive behavior, impulsivity, anxiety, and posttraumatic stress symptoms and to improve self-regulation and pro-social behavior [39
]. Serious gaming and VR are thus promising tools for enhancing psychological interventions and have also gained recognition in forensic psychiatry and criminology (e.g., [44
Recently, a VR aggression prevention therapy (VRAPT) was developed and examined among forensic psychiatric inpatients [48
]. This intervention consisted of 16 one-hour individual treatment sessions twice a week. Their results showed that aggressive behavior did not decrease after VRAPT as compared to waiting list. However, hostility, anger control, and non-planning impulsiveness did improve after treatment, but these improvements were not maintained in a 3-month follow-up. The results of this study highlight the challenge of developing an effective VR intervention but also show that VR has potential as an intervention-tool in forensic clinical practice. However, whether the combination of serious gaming and VR can be used to train underlying automatic processes, such as an approach tendency towards a potential social threat has not yet been investigated.
For the current study, the motivational modification paradigm [26
], serious gaming, and VR technology were combined to create a new treatment tool for the treatment of aggressive behavior: the Virtual Reality Game for Aggression Impulsive Management (VR-GAIME) [49
]. The VR-GAIME adopted the rationale of the approach-avoidance bias modification paradigm that was investigated by [22
]. Instead of joystick movements, however, the VR-GAIME manipulated whole body movements in an immersive environment. During the VR-GAIME, each participant got assigned to the role of a courier who had to collect packages in a shopping street. In the shopping street, the participant was met by avatars who were acting in either an agreeable or disagreeable manner. Patients in the experimental training condition were trained to respond with avoidance behavior to anger-relevant situations. In the control condition, patients played the same game as patients in the experimental condition but did not encounter any disagreeable avatars and hence did not receive any training about anger-relevant situations.
The aim of the current randomized controlled trial was to investigate the effect of the VR-GAIME on the level of aggressive behavior of forensic psychiatric outpatients, who were randomly allocated to the VR-GAIME or control game. In both conditions, the game was provided in combination with treatment as usual which consisted of the Aggression Replacement Training (ART) [50
]. The original ART consists of three modules: (1) social skills training, which focuses on responding in a pro-social way to difficult situations instead of using aggression; (2) anger control training, which teaches to gain more control over aggressive thoughts and aggressive impulses; and (3) moral reasoning training, where patients learn to recognize certain cognitive distortions relating to aggression by themselves and think in a less egocentric way by means of group discussions.
Anger and aggressive impulses were measured using self-report and a validated laboratory paradigm as well as clinician ratings. Moreover, approach and avoidance tendencies were assessed using self-report. Additionally, drop-out rates among outpatients receiving aggression treatment are high [52
] and are associated with psychopathy and proactive aggression [53
]. To determine whether the drop-out number was in line with previous studies or might be lower/higher due to the game, we included measures of psychopathy and aggression subtype. Subsequently, aggression treatment might also change other emotions than anger, and the effects might affect other biases in processing facial expression. To examine this possibility, a self-report measure for distinct emotions and a measure for a hostile interpretation bias were included. We hypothesized that the combination of the VR-GAIME and ART would be more successful in reducing anger and aggressive behavior relative to the control condition. Finally, individual differences in treatment effects were explored by examining whether aggression tendency and aggression subtype, approach/avoidance tendencies, psychopathy, and emotion experience at baseline were associated with the change in aggression during treatment.
Priori laboratory studies indicated that training avoidance movements to angry faces may lower anger and aggression among people with aggression-prone personality traits [26
]. Based on this basic principle, we developed a VR-GAIME and tested its efficacy in a randomized controlled trial among a group (N = 30) of forensic psychiatric outpatients characterized by aggression regulation problems. Results suggested that aggressive behavior reduced over the course of treatment. Moreover, high levels of trait anger and reactive aggression were associated with higher levels of aggressive behavior during the course of treatment. Contrary to expectations, the VR-GAIME was not more successful in reducing anger and aggressive behavior relative to the control condition. In the following paragraphs, we consider possible reasons for the lack of effectiveness of the VR-GAIME, along with ways in which future work may realize the unfulfilled potential of combining serious gaming and VR in creating effective aggressive management interventions.
We see four potential explanations why the VR-GAIME could have failed to show effects in the present research. A first potential reason for the lack of effects of the VR GAIME is theoretical: perhaps training avoidance behavior does not reduce anger and aggression among aggression-prone individuals. We regard this potential explanation as unlikely. This is because prior findings by our team were clear-cut, in that we were reliably able to demonstrate that training avoidance behavior to angry faces lowers anger and aggression among aggression-prone people [26
]. A second potential explanation for the lack of effects of the VR-GAIME is lack of statistical power: our sample was twice as small as we had originally aimed for, which meant that the present research had limited statistical power. Although we grant that the present study was limited in this regard, we were still able to replicate the effects of individual differences in trait anger and aggressive personality. Because these individual differences are well-established and tend to have statistical effects in the small-to-moderate range, our individual-difference findings suggest that our study design was still sufficiently sensitive to detect small-to-moderate effects. Consequently, we are inclined believe that the lack of effects of the VR-GAIME was not, or at least not entirely, due to lack of statistical power.
A third potential explanation for the lack of effects of the VR-GAIME is the distinctive population we examined in the present study. In prior studies, the avoidance training had been used among university students. By contrast, in the present study, our sample consisted of forensic psychiatric outpatients. It is conceivable, and even plausible, that forensic psychiatric outpatients are a more difficult group to influence with any kind of training program. Moreover, it may be that forensic psychiatric outpatients are not uniformly characterized by reactive approach motivation. Theoretically, the motivational training should only be effective among people whose anger management problems derive from an excess of reactive approach motivation. In future research, it would be helpful to conduct more refined diagnostic tests to screen out those forensic psychiatric outpatients who are most likely to benefit from motivational avoidance training.
Finally, a fourth potential explanation for the lack of effects of the VR-GAIME may be that the translation of the intervention to a gamified VR-format was imperfect. We regard this explanation as plausible. The design process of the VR-GAIME was complex and far from straightforward. We had to make many design decisions (e.g., the cover-story, specific gaming elements, how different points could be earned) ‘in the blind’, without a clear theoretical rationale. As a results, it is possible that the final version of the VR-GAIME diverged so much from the original joystick training [26
] that it could no longer be expected to have the same effects. It is important to note that the decisions about the specific training components were in line with previous research. An important avenue for future research on gamification of neurocognitive tasks is to carefully validate the translation of the original to the new task before implementation in research/clinical practice. Unfortunately, in the current study, the timespan for a thorough validation procedure was too limited. Moreover, important differences exist between the two conditions of the VR-GAIME that might have played a role in the unexpected findings and that need to be reconsidered in future research. In both versions, in each level, eight avatars approached the patient. This entails that in the experimental condition, each level consisted of four agreeable and four disagreeable avatars, but in the control game, each level consisted of eight agreeable avatars. The latter could have provided a general positivity training. A type of training which can have beneficial effects in its own right and is based on the idea that individuals with emotional disorders are characterized by a lack of positive biases [79
Even though the VR-GAIME did not yield the expected reduction of aggressive behavior during treatment, the game did have another important clinical effect. Several patients reported that playing the game gave them insight in their own as well as in others behavior. These findings are in line with the recent VRAPT study among forensic psychiatric inpatients [48
]. This study found no significant reductions in aggressive behavior after VRAPT compared to a waiting list but patients, as well as clinicians, were positive about this intervention. Moreover, after VRAPT, patients reported more insight into their triggers and more awareness of their physiological arousal. In general, forensic psychiatric outpatients are thought to display a lack in reflection and introspection (e.g., [16
]). It would clinically be highly relevant if a tool/intervention such as the VR-GAIME or VRAPT could help improve these abilities. Prospective research should elucidate which component of the game increased this insight and how this can be developed in further detail in order to create an add-on tool for this specific purpose. Specific attention should be paid to the outcome measures as the materials used in the current study focused on emotional and behavioral components and did not give insight in changes in reflective abilities. Several patients also reported that they believed the game was little challenging after playing it a few times and that it did not have enough variety. The VR-GAIME may thus be developed further and expanded with different situations and possibly also with more challenging components.
The present study inevitably has limitations. First, due to difficulties with the data collection and high drop-out rates, the required sample size was not met. Consequently, the current sample size was small, and the study is underpowered. The results have to be interpreted with care and replicated in larger samples. Second, except for one, all measurements consisted of self-report. It is questionable whether a population of forensic psychiatric outpatients is fully able to reflect on their own behavior and whether they are willing to answer genuinely. Third, some measurements showed poor reliability. These results have to be interpreted with care. Fourth, no follow-up measurement was included. This would enable one to determine the long-term effects or possible delayed effects of the VR-GAIME and ART. Fifth and last, the present study included only male forensic psychiatric outpatients, which means that the current findings may not be generalizable to a female population with aggression regulation problems.