Neuromodulation can reduce aggressive behavior elicited by violent video games

Research has shown that exposure to violent media increases aggression. However, the neural underpinnings of violent-media-related aggression are poorly understood. Additionally, few experiments have tested hypotheses concerning how to reduce violent-media-related aggression. In this experiment, we focused on a brain area involved in the regulation of aggressive impulses—the right ventrolateral prefrontal cortex (rVLPFC). We tested the hypothesis that brain polarization through anodal transcranial direct current stimulation (tDCS) over rVLPFC reduces aggression related to violent video games. Participants (N = 79) were randomly assigned to play a violent or a nonviolent video game while receiving anodal or sham stimulation. Afterward, participants aggressed against an ostensible partner using the Taylor aggression paradigm (Taylor Journal of Personality, 35, 297–310, 1967), which measures both unprovoked and provoked aggression. Among those who received sham stimulation, unprovoked aggression was significantly higher for violent-game players than for nonviolent-game players. Among those who received anodal stimulation, unprovoked aggression did not differ for violent- and nonviolent-game players. Thus, anodal stimulation reduced unprovoked aggression in violent-game players. No significant effects were found for provoked aggression, suggesting tit-for-tat responding. This experiment sheds light on one possible neural underpinning of violent-media-related aggression—the rVLPFC, a brain area involved in regulating negative feelings and aggressive impulses.     

Exploring the effects of EEG signals on collision cases happening in the process of young drivers’ braking

Detecting mental states in drivers offers an opportunity to reduce accidents by triggering alerts and signaling the need for rest or renewed focus. Here we used electroencephalography (EEG) to measure brain signals in young drivers operating a driving simulator to detect mental states and predict accidents. We measured reaction times to unexpected hazardous events and correlated them with EEG signals measured from the frontal, parietal, and temporal cortices as well as the central sulcus (corresponding to motor cortex). We found that EEG signals in the relative beta (power in beta (13–30 Hz) relative to total power of the EEG (0.5–30 Hz)), alpha/delta, alpha/theta, beta/delta, beta/theta frequency bands were higher for collisions than successful collision avoidance, and that the key decision-making period is the 2nd second before braking. Importantly, a decision tree classifier trained on these neural signals predicted collision avoidance outcomes. Then based on random forest model, we extracted three critical neural signals (beta/delta_frontal, relative beta_parietal and relative beta_central Sulcus) to classify collision avoidance outcomes. Our findings suggest measuring EEG during driving may provide useful signals for enhancing driver safety.     

A strong parietal hub in the small-world network of coloured-hearing synaesthetes during resting state EEG

We investigated whether functional brain networks are different in coloured-hearing synaesthetes compared with non-synaesthetes. Based on resting state electroencephalographic (EEG) activity, graph-theoretical analysis was applied to functional connectivity data obtained from different frequency bands (theta, alpha1, alpha2, and beta) of 12 coloured-hearing synaesthetes and 13 non-synaesthetes. The analysis of functional connectivity was based on estimated intra-cerebral sources of brain activation using standardized low-resolution electrical tomography. These intra-cerebral sources of brain activity were subjected to graph-theoretical analysis yielding measures representing small-world network characteristics (cluster coefficients and path length). In addition, brain regions with strong interconnections were identified (so-called hubs), and the interconnectedness of these hubs were quantified using degree as a measure of connectedness. Our analysis was guided by the two-stage model proposed by Hubbard and Ramachandran (2005). In this model, the parietal lobe is thought to play a pivotal role in binding together the synaesthetic perceptions (hyperbinding). In addition, we hypothesized that the auditory cortex and the fusiform gyrus would qualify as strong hubs in synaesthetes. Although synaesthetes and non-synaesthetes demonstrated a similar small-world network topology, the parietal lobe turned out to be a stronger hub in synaesthetes than in non-synaesthetes supporting the two-stage model. The auditory cortex was also identified as a strong hub in these coloured-hearing synaesthetes (for the alpha2 band). Thus, our a priori hypotheses receive strong support. Several additional hubs (for which no a priori hypothesis has been formulated) were found to be different in terms of the degree measure in synaesthetes, with synaesthetes demonstrating stronger degree measures indicating stronger interconnectedness. These hubs were found in brain areas known to be involved in controlling memory processes (alpha1: hippocampus and retrosplenial area), executive functions (alpha1 and alpha2: ventrolateral prefrontal cortex; theta: inferior frontal cortex), and the generation of perceptions (theta: extrastriate cortex; beta: subcentral area). Taken together this graph-theoretical analysis of the resting state EEG supports the two-stage model in demonstrating that the left-sided parietal lobe is a strong hub region, which is stronger functionally interconnected in synaesthetes than in non-synaesthetes. The right-sided auditory cortex is also a strong hub supporting the idea that coloured-hearing synaesthetes demonstrate a specific auditory cortex. A further important point is that these hub regions are even differently operating at rest supporting the idea that these hub characteristics are predetermining factors of coloured-hearing synaesthesia.     

6-12岁儿童额叶自发脑电频谱相干的特点

EEG频谱相干分析发现额叶发育在童年中期存在可能的加速期。针对这一问题,本研究通过记录75名6至12岁正常儿童静坐和闭目状态下的自发脑电,分析δ、θ、α和β基本脑电频段下31对电极相干的变化情况,系统探索了该年龄段儿童额叶自发脑电频谱相干的变化特点,结果发现:θ波活动普遍强于α和β波活动;6至12岁儿童额叶内、额叶与其他脑叶间相干在整体上表现为随年龄增长而增加的趋势;额叶内、额叶与其他脑叶间相干在各频段均表现为7岁、11岁突增,10岁、12岁表现为高峰。上述结果支持6至12岁儿童额叶发育存在加速变化的结论。     

Executive cognitive functioning and the recognition of facial expressions of emotion in incarcerated violent offenders, non-violent offenders, and controls

Violence is a social problem that carries enormous costs; however, our understanding of its etiology is quite limited. A large body of research exists, which suggests a relationship between abnormalities of the frontal lobe and aggression; as a result, many researchers have implicated deficits in so-called "executive function" as an antecedent to aggressive behaviour. Another possibility is that violence may be related to problems interpreting facial expressions of emotion, a deficit associated with many forms of psychopathology, and an ability linked to the prefrontal cortex. The current study investigated performance on measures of executive function and on a facial-affect recognition task in 20 violent offenders, 20 non-violent offenders, and 20 controls. In support of our hypotheses, both offender groups performed significantly more poorly on measures of executive function relative to controls. In addition, violent offenders were significantly poorer on the facial-affect recognition task than either of the other two groups. Interestingly, scores on these measures were significantly correlated, with executive deficits associated with difficulties accurately interpreting facial affect. The implications of these results are discussed in terms of a broader understanding of violent behaviour.     

Driving aggression in forensic and non‐forensic populations: Relationships to self‐reported levels of aggression,anger and impulsivity

A series of four questionnaires — the Buss‐Perry Aggression Questionnaire (AQ), the Barratt Impulsivity Scale (BIS‐11), the Driving Anger Scale (DAS) and a Driving Violence Inventory (DVI) — were administered to a sample of 473 British drivers consisting of undergraduates (N=185), members of the public (N=106) and offenders (N=182) serving sentences in closed prisons in England (violent=82, non‐violent=100). Offenders consistently rated acts of driving aggression as less severe compared with other drivers. Offender attributions of driving violence differed to other drivers in that they were equally likely to perceive obscene gesturing as high or low intensity responses; they also viewed assault as a high intensity response whereas members of the public rated it more severely. Trait levels of anger and aggression were the predictors of driving violence in all groups but previous aggressive behaviour was only a predictor for the offenders. Gender and age were found to be predictors of aggressive driving in non‐offenders. Even with the effects of age controlled, offenders (and violent offenders in particular) scored higher on measures of driving anger and aggression. These data suggest that offenders differ in their perceptions of aggressive behaviours experienced in everyday driving and as a consequence are more likely to commit acts that other drivers perceive as violent. As offenders are known to display similar perceptual biases in other domains, identified as precursors to their aggressive behaviour, it seems likely that experience effects (as reflected in the trait measures) underpin differences in driving aggression between offenders and non‐offenders.     

Intelligence and neural efficiency: Measures of brain activation versus measures of functional connectivity in the brain

The neural efficiency hypothesis of intelligence suggests a more efficient use of the cortex (or even the brain) in brighter as compared to less intelligent individuals. This has been shown in a series of studies employing different neurophysiological measurement methods and a broad range of different cognitive task demands. However, most of the studies dealing with the brain–IQ relationship used parameters of absolute or relative brain activation such as the event-related (de-)synchronization of EEG alpha activity, allowing for interpretations in terms of more or less brain activation when individuals are confronted with cognitively demanding tasks. In order to investigate the neural efficiency hypothesis more thoroughly, we also used measures that inform us about functional connectivity between different brain areas (or functional coupling, respectively) when engaged in cognitive task performance. Analyses reveal evidence that higher intelligence is associated with a lower brain activation (or a lower ERD, respectively) and a stronger phase locking between short-distant regions of the frontal cortex.     

Low blood glucose nadir in the glucose tolerance test and homicidal spouse abuse

The purpose of the study was to investigate whether homicidal spouse abuse offenders with a low blood glucose nadir in glucose tolerance test (GTT) showed more instances of repeated and severe aggression and criminality than counterparts with more normal GTTs. An attempt was also made to determine whether personality profiles on the Minnesota Multiphasic Personality Inventory (MMPI) differentiated between the groups. Altogether, 60 male homicidal offenders were studied. Those with low values had been repeatedly violent and impulsive under the influence of alcohol in relationships but also outside the home. The homicidal act usually occurred under the influence of alcohol with no clear recollection. These offenders had normal MMPI but some of them showed motor restlessness and irritability during the GTTs. The possible connections with enhanced glucose and abnormal brain serotonin metabolism among habitually violent and impulsive offenders are discussed.     

Putative EEG measures of social anxiety: Comparing frontal alpha asymmetry and delta–beta cross-frequency correlation

The goal of the present study was to examine whether frontal alpha asymmetry and delta–beta cross-frequency correlation during resting state, anticipation, and recovery are electroencephalographic (EEG) measures of social anxiety. For the first time, we jointly examined frontal alpha asymmetry and delta–beta correlation during resting state and during a social performance task in high (HSA) versus low (LSA) socially anxious females. Participants performed a social performance task in which they first watched and evaluated a video of a peer, and then prepared their own speech. They believed that their speech would be videotaped and evaluated by a peer. We found that HSA participants showed significant negative delta–beta correlation as compared to LSA participants during both anticipation of and recovery from the stressful social situation. This negative delta–beta correlation might reflect increased activity in subcortical brain regions and decreased activity in cortical brain regions. As we hypothesized, no group differences in delta–beta correlation were found during the resting state. This could indicate that a certain level of stress is needed to find EEG measures of social anxiety. As for frontal alpha asymmetry, we did not find any group differences. The present frontal alpha asymmetry results are discussed in relation to the evident inconsistencies in the frontal alpha asymmetry literature. Together, our results suggest that delta–beta correlation is a putative EEG measure of social anxiety.     

Oscillatory brain activity differentially reflects false belief understanding and complementation syntax processing

False belief understanding (FBU) enables people to consider conflicting beliefs about the same situation. While language has been demonstrated to be a correlate of FBU, there is still controversy about the extent to which a specific aspect of language, complementation syntax, is a necessary condition for FBU. The present study tested an important notion from the debate proposing that complementation syntax task is redundant to FBU measures. Specifically, we examined electrophysiological correlates of false belief, false complementation, and their respective true conditions in adults using electroencephalography (EEG), focusing on indices of oscillatory brain activity and large-scale connectivity. The results showed strong modulation of parieto-occipital alpha (8–12 Hz) and beta (13–20 Hz) power by the experimental manipulations, with heightened sustained alpha power reflective of effortful internal processing observed in the false compared to the true conditions and reliable beta power reductions sensitive to mentalizing and/or syntactic demands in the belief versus the complementation conditions. In addition, higher coupling between parieto-occipital regions and widespread frontal sites in the beta band was found for the false-belief condition selectively. The result of divergence in beta oscillatory activity and in connectivity between false belief and false complementation does not support the redundancy hypothesis.     

Assessing changes in brain electrical activity and functional connectivity while overtaking a vehicle

ABSTRACT

Driving is a daily requirement and an indispensable activity for many people. However, still little is known about how driving is supported by the brain. We used electroencephalography to study the changes in brain activity and its functional connectivity in a simulated driving task. We focused on overtaking and studied this activity in three phases: before overtake, during overtake, and after overtake. Our results showed that mu power in motor and sensorimotor areas decreased during overtake and again increased after overtake. On the other hand, beta oscillations in frontal areas were at their highest level in the “before overtake” phase. It can be interpreted that the “before overtake” was the most attention-demanding phase. In addition, we found that the connectivity between right and left prefrontal regions and right and left occipital regions in alpha (and mu) band power was significantly stronger in the “during overtake” compared to the other two conditions.     

Adolescent anxiety and aggression can be differentially predicted by electrocortical phase reset variables

Increasing evidence supports the notion that both internalizing (e.g., anxiety) and externalizing (e.g., aggression) behavioral dysregulation are associated with abnormal communication between brain regions. Electroencephalographic (EEG) signals across two electrode sites are said to be coherent with one another when they show consistent phase relations. However, periods of desynchrony with shifting of phase relations are a necessary aspect of information processing. The components of EEG phase reset (‘locking’ when two regions remain in synchrony, and ‘shifting’ when the two regions desynchronize momentarily) show dramatic changes across development. We collected resting EEG data from typically developing 12 to 15-year-olds and calculated phase shift and lock values in the alpha frequency band across 14 pairs of electrodes varying in inter-electrode distance. A composite measure of participants’ aggression levels was positively associated with phase shifting, particularly in the low alpha frequency range, most strongly over the left hemisphere, consistent with the relatively greater left-prefrontal activity reported in aggressive adults. A composite measure of anxiety levels was positively associated with alpha phase locking at sites over both hemispheres, consistent with changes in connectivity reported during anxious thinking in adults. Associations with anxiety could not be explained by traditional EEG coherence measures and suggest that phase shifting and locking might provide an important non-invasive associate of clinically problematic behavior.     

弥散张量成像在语言认知神经科学研究中的应用

人类的语言功能不仅仅基于以额叶、颞叶为代表的语言脑区灰质皮层的激活, 更重要的是基于这些脑区之间白质纤维束的连接。随着各种脑成像技术的逐渐成熟, 基于核磁共振的弥散张量成像技术在语言认知领域展现出越来越重要的作用。弥散张量成像在语言认知研究上的应用, 可以将其与行为测查、功能定位成像、功能连接、全脑网络等多种分析方法结合来共同研究语言认知, 进而从脑结构的角度来探究语言与脑的关系。     

情绪如何引发暴力犯的攻击?基于情绪调节理论的解释

本文基于情绪调节理论, 以暴力犯为被试, 通过2项研究探究了情绪在攻击产生过程中的作用。研究1采用改编的反应时竞争范式测量个体攻击行为。结果发现, 情绪调节动机在负性情绪与攻击间起完全中介作用, 证实了负面情绪状态下, 暴力犯会为了调节情绪而实施攻击。研究2进一步表明, 攻击的确能起到调节情绪的作用。具体来说, 在暴力犯群体中, 实施反应性攻击之后, 会伴随着正性情绪的提升和负性情绪的下降; 实施主动性攻击之后, 个体的正性情绪和负性情绪都会提升。文章从对攻击结果的预期和攻击的实际效果两个角度, 对攻击的情绪调节理论进行了验证, 为情绪在攻击产生过程中的作用提出了新的解释。今后的研究和实践过程中, 应设法避免个体通过攻击调节情绪, 引导其使用合理的方式调节情绪以减少攻击行为的产生。     

Deindividuation,anonymity, and violence: findings from Northern Ireland

The author examined the relation between anonymity and aggression in violent interpersonal assaults that occurred in Northern Ireland. Of the 500 violent attacks that the author studied, 206 were carried out by offenders who wore disguises to mask their identities. The findings revealed that significant positive relationships existed between the use of disguises and several measures of aggression. Disguised offenders inflicted more serious physical injuries, attacked more people at the scene, engaged in more acts of vandalism, and were more likely to threaten victims after the attacks. The author discussed these results within the framework of deindividuation theory.     

This is your brain on violent video games: Neural desensitization to violence predicts increased aggression following violent video game exposure

Previous research has shown that media violence exposure can cause desensitization to violence, which in theory can increase aggression. However, no study to date has demonstrated this association. In the present experiment, participants played a violent or nonviolent video game, viewed violent and nonviolent photos while their brain activity was measured, and then gave an ostensible opponent unpleasant noise blasts. Participants low in previous exposure to video game violence who played a violent (relative to a nonviolent) game showed a reduction in the P3 component of the event-related brain potential (ERP) to violent images (indicating physiological desensitization), and this brain response mediated the effect of video game content on subsequent aggressive behavior. These data provide the first experimental evidence linking violence desensitization with increased aggression, and show that a neural marker of this process can at least partially account for the causal link between violent game exposure and aggression.     

Socially Explosive Minds: The Triple Imbalance Hypothesis of Reactive Aggression

ABSTRACT The psychobiological basis of reactive aggression, a condition characterized by uncontrolled outbursts of socially violent behavior, is unclear. Nonetheless, several theoretical models have been proposed that may have complementary views about the psychobiological mechanisms involved. In this review, we attempt to unite these models and theorize further on the basis of recent data from psychological and neuroscientific research to propose a comprehensive neuro-evolutionary framework: The Triple Imbalance Hypothesis (TIH) of reactive aggression. According to this model, reactive aggression is essentially subcortically motivated by an imbalance in the levels of the steroid hormones cortisol and testosterone (Subcortical Imbalance Hypothesis). This imbalance not only sets a primal predisposition for social aggression, but also down-regulates cortical–subcortical communication (Cortical-Subcortical Imbalance Hypothesis), hence diminishing control by cortical regions that regulate socially aggressive inclinations. However, these bottom-up hormonally mediated imbalances can drive both instrumental and reactive social aggression. The TIH suggests that reactive aggression is differentiated from proactive aggression by low brain serotonergic function and that reactive aggression is associated with left-sided frontal brain asymmetry (Cortical Imbalance Hypothesis), especially observed when the individual is socially threatened or provoked. This triple biobehavioral imbalance mirrors an evolutionary relapse into violently aggressive motivational drives that are adaptive among many reptilian and mammalian species, but may have become socially maladaptive in modern humans.     

The neural basis of syntactic deficits in primary progressive aphasia

Patients with primary progressive aphasia (PPA) vary considerably in terms of which brain regions are impacted, as well as in the extent to which syntactic processing is impaired. Here we review the literature on the neural basis of syntactic deficits in PPA. Structural and functional imaging studies have most consistently associated syntactic deficits with damage to left inferior frontal cortex. Posterior perisylvian regions have been implicated in some studies. Damage to the superior longitudinal fasciculus, including its arcuate component, has been linked with syntactic deficits, even after gray matter atrophy is taken into account. These findings suggest that syntactic processing depends on left frontal and posterior perisylvian regions, as well as intact connectivity between them. In contrast, anterior temporal regions, and the ventral tracts that link frontal and temporal language regions, appear to be less important for syntax, since they are damaged in many PPA patients with spared syntactic processing.     

Evaluation on Directed Functional Brain Connectivity during the Expert Rifle Pre-shot Period

Experts require long-term and intense practice to acquire extraordinary motor skills that be known as the brain function regulator. However, the brain function network mechanism of rifle shooters is still unclear. The generalized orthogonalized partial directed coherence (gOPDC) algorithm and local efficiency significance analysis method (LESA) was applied to quantify the difference in directed functional networks between expert and novice rifle shooters during the pre-shot period. The more directed functional connections were observed in alpha and low-beta frequency bands as compared to other bands. Moreover, comparing with the novice’s fluctuant connection, the values of connection (P3→C3) strength were increasing steadily in the experts during the pre-shot period. Fewer connections in left hemisphere networks were obtained in the experts than in the novices. The results validated the “neural efficiency” hypothesis in experts. Moreover, the strength of the functional connection (P3→C3) in the alpha and beta bands serves as a distinguishing feature between experts and novices.     

Leben ohne Gewalt organisieren

Several runs of a cognitive-behavioral group-based training program for violent offenders in a youth detention center were evaluated. The training aims at reducing disposition towards violence, promoting responsibility and strengthening personal and social resources. The 49 participants were compared to 47 non-participating violent offenders. For the participants a reduction of several facets of aggression and an increase of responsibility for the offence was observed in a pre-post-comparison. However, treatment effects appear to decrease with longer observation time. Competencies such as empathy were not affected by the training. Furthermore, participants showed no difference to non-participants regarding officially recorded violent recidivism.