Attentional Bias In Individuals With Different Level Of Implicit/Explicit Aggression:Behavior And Brain Mechanism

A growing body of literature is focusing on aggression and violent behavior, especially the influencing factors and mechanisms of aggression. Understanding the mechanisms underlying aggressive behavior may help us to advance our knowledge on the etiology of aggressive behavior, which could translate into prevention and treatment programs. With the upsurge of the cognitive neuroscience, more and more literatures indicate that cognitive factors are thought to play a critical role in aggressive behavior; examination of these factors may therefore he to to elucidate the underlying mechanisms.Aggression can be classified into implicit aggression and explicit aggression. Moreover, implicit aggression and explicit aggression have low relation with each other. Considerable evidence from behavioral studies has indicated that high-aggression individuals tend to perceive ambiguous situations as more hostile and/or more threatening than low-aggression controls. It is suggested that this difference is partially due to variations in attentional bias. In other words, aggressive subjects show a preference for hostile stimuli and make the hostile interpretation according to their aggressive script.Attentional bias is defined as the expression of preference for some stimuli. Behavioral studies have recently provided lots of evidence on this issue. Considerable evidence from behavioral studies has indicated that high aggression displays attentional bias. Dodge et al. argue that aggression involves neurobiologically-based deficits in information processing, especially attentional processing. Although a growing body of literature show that aggression is common abnormity of brain, most of these findings are from studies on animal or aggressive patients. As a result, we need the further research to determine whether the results can be applied to the common people.The present study researches the individuals with different level of aggression on behavioral and ERP experiment. On the base of the confirmation of the existence of implicit aggression and exploration of the relationship, the study examine the attentional bias among different level of aggression. The present study includes four experiments. The first experiment use gender to test the different influences on implicit aggression and explicit aggression. The second experiment aims to explore the relationship between implicit aggression and explicit aggressioa The third experiment use Buss-Perry Aggression Questionnaire and implicit associate test (IAT) to test participants’explicit and implicit aggression level respectively. Those with scores in the top quartile of the distribution were allocated to the high-power group, and those with scores in the bottom quartile of the distribution to the low-power group. Furthermore, using dot probe task to research the attentional bias among different level of aggression, The fourth experiment (ERP) use the emotional Stroop task to examine the mechanism of aggression. The results revealed that:(1) By means of experimental dissociation, it was found that gender produced different impact on implicit aggression and explicit aggression It confirmed the existence of implicit aggression.(2) Implicit aggression and explicit aggression have low relation with each other. They are two different structures which constitute the dual aggression model.(3) The high explicit aggression individuals showed significantly longer response latencies than low explicit aggression individuals. It confirmed that high explicit aggression individuals have attentional bias.(4) The result of the experiment illustrated that compared to neutral facial expression, high explicit aggression individuals showed smaller N100amplitude on angry facial expression, indicating that the ability to allocate and regulate attention was weak.(5) The analysis of the P300components showed that the amplitude was smaller among high explicit aggression individuals than low explicit aggression individuals, indicating aggressive person had cognitive deficits, especially attention deficits. The single ERP study also found that members high in aggression displayed smaller N400amplitude than low explicit aggression individuals, indicating more resources may be needed for high explicit aggression individuals to suppress outward angry responses.(6) Compared to low explicit aggression members, high explicit aggression members showed lower amplitude on Czposition of N100and FCz position ofN400. However, the result of implicit aggression was contrary to explicit aggression. The difference between explicit aggression and implicit aggression on EEG provided cognitive neuroscience evidence for the dual aggression model.