انگیختگی فیزیولوژیک، پرخاشگری واکنشی و القاء واکنش آرم سازی ناسازگار

This review examines the major cognitive/social approaches to reducing reactive aggression and their interdependency on neural mechanisms associated with arousal. According to psychological theory, physiological arousal serves as a nonspecific energizer of cognitively defined emotions. Physiological models emphasize a bottom-up approach, many higher cortical functions serve to reduce heightened arousal and these reductions are essential before cognitive techniques can modulate aggressive behavior. Higher cortical functions are associated with complex cognitive processes necessary for self-control, anticipating consequences, and behavioral inhibition. Heightened arousal interferes with cognitive performance; disinhibiting aggression and reinforcing behavior that reduces arousal. Studies manipulating empathy, humor and sexual content have demonstrated efficacy of incompatible responses to reduce anger and aggression, but when attributions are negative and arousal high all of these manipulations can increase chances of overt aggression. The incompatible response hypothesis is extended beyond empathy, humor, and sexual arousal to include relaxation techniques for prevention and control of aggression. Cognitive-behavioral therapeutic programs have successfully reduced aggression by combining relaxation, systematic desensitization, and biofeedback with cognitive restructuring and anger management training.

ALTHOUGH THERE HAVE been divergent opinions concerning the definition of aggression, most researchers in this field have moved toward acceptance of two different kinds of aggressive behavior (Baron & Richardson, 1994). Reactive aggression involves responses undertaken to terminate or reduce aversive conditions or retaliate against a perceived threat or provocation. Reactive aggressors are driven by strong internal arousal to assault the target, not considering costs or benefits, lashing out at a victim with little or no self-restraint (Berkowitz, 1993). In contrast, instrumental aggression involves proactive behaviors designed to attain a specific goal other than seeking to harm or injure the person attacked. Many robbers are instrumental aggressors, as are batterers, who want to assert their dominance and control over others; habitually using force in a cool and premeditated manner to attain their objectives. A central theme in this review is that heightened arousal is an antecedent of reactive aggression in contrast to the more calm and controlled behavior associated with instrumental aggression. There are situations where people display a mixture of both proactive and reactive aggression; for example, when an aggressor’s commands are resisted or refused, he might become emotionally aroused and impulsively strike out at a victim. The aim of this review is to examine various theoretical and therapeutic approaches that reduce reactive aggression, particularly in terms of physiological arousal. Implicit in many theories of aggression are conceptual links between intensity of stimulated physiological arousal and probability of aggressive response Berkowitz 1990 and Zillmann 1983. First, the review examines how conceptual links were historically derived from psychophysiological models of emotion and how current neurophysiological models suggest ways of reducing aggression. Second, we present an overview of research that suggests that heightened arousal interferes with the cognitive constraints to aggression, motivates the person and transfers from nonaggressive sources to amplify aggression. Finally, studies of empathy, humor, and sexual content are compared to therapeutic uses of behavioral techniques to lower arousal as incompatible responses to aggression. In general, relaxation can lower arousal and combined with cognitive self-control skills, can lessen the likelihood of emotional outbursts and reactive aggression. Neurophysiological models of arousal According to Berlyne’s (1960) theory, arousal is an intervening variable used to clarify such diverse phenomena as motivation, sleep, attention, and emotion. Arousal is a term widely used to describe a nonspecific facilitation of cortical transmission that results in increased alertness, responsiveness, and vigilance (Hebb, 1972). According to Berlyne (1960), the portion of the nervous system hypothesized to control alertness and attention is the reticular arousal system. This system contains diffuse ascending cortical projections that respond to the emotional intensity or urgency of stimuli based on past experience and physiological biases. Berlyne’s (1960) conception of the reticular arousal system took on new meaning as knowledge of the functions of some of the specific neurochemical pathways mediating arousal became more apparent (Koob, 1991). While some researchers have hypothesized one mechanism for arousal, aggression research suggests that there are many specific and nonspecific brain systems affected by arousal (Laborit, 1993). There is continual communication and control exerted between cortical, subcortical, and autonomic levels of the nervous system. Investigators generally think of top-down activity when discussing self-control of aggression (Leventhal, 1991). For example, people are sometimes capable of inhibiting overt violence and to some degree voluntarily controlling facial expression by cognitive processes. A thought or mental image can initiate the body’s adrenal cortical responses, heart rate, and immune activity (Stemmler, 1989). Cognitive models of anger and aggression give relatively little attention to bottom-up processing, though influences from lower to upper levels may be the most pervasive and important predictor of aggressive behavior (Pfister & Muir, 1992). Reactive physical violence often has a primitive subcortical quality—kicking, gouging, scratching, hitting, spitting, biting. A wife is picked up bodily and thrown against a wall. Windows are broken, doors smashed, and holes punched in walls. A man kills another by a single stab wound to the heart, and then delivers more stabs to the dead body. Without thinking, a young woman bites her crying baby on the check, leaving a life-long scar (Elliott, 1988). Reactive aggression is mediated by subcortical centers and modulated by higher cognitive processes. Peripheral versus central theories of emotion In the history of theory and research on emotions, a major topic is the issue of specific central physiological states versus general autonomic arousal as the substrate of different emotions. William James (1884) held that subjective feelings like anger are produced by afferent feedback from visceral and somatic changes following the perception of a stimulus object. The hypothesis that feedback from peripheral changes may account for the specificity of different emotions was rejected by Cannon (1927). He claimed that the particular quality of emotional experiences is due to specific patterns of activity in the central nervous system. Papez (1937) extended Cannon’s centralistic perspective to include a detailed subcortical limbic circuit for aggression and rage (Huber & Gramer, 1993). An intermediate position between the peripheral and central view was taken by Schachter and Singer (1962). Schachter and Singer (1962) moved arousal back to the central position in the theory of emotion, advancing the proposition that sympathetic arousal is a nonspecific energizer of emotion. Occurrence of an emotional state is the result of an interaction between two components: nonspecific physiological arousal and cognition about the arousing situation. In other words, if physiological arousal of sufficient intensity is present, the particular quality of experienced emotional state is determined exclusively by cognitive processes (Huber & Gramer, 1993). The specific emotion experienced is a function of cognitive labeling determined by environmental cues and past experience (Lazarus, 1991). Anger is the result of autonomic arousal associated with and perceived as an appropriate response to provocation or aversion. The same autonomic arousal in the presence of flight-producing cues, would be experienced as fear. Data supporting the peripheral view are (a) arousal induced by stimuli including exercise, drugs, or noise enhances aggression when the arousal can be attributed to this provocation; (b) attribution of arousal to sources other than the provoker reduces aggressive responding; and (c) reduction or elimination of autonomic arousal by pharmacological blockage of peripheral β-adrenergic receptors reduces self-reports of anger (Potegal, 1994). In contrast, Cannon’s classic experimental study found that surgical interruption of outflow through the sympathetic ganglia did not alter defensive behavior in cats (Cannon, Newton, Bright, Menken, & More, 1929). Kaplan and Manuch (1989) failed to find any effects of β-adrenergic blockade on aggression in monkeys using drug doses that clearly suppressed peripheral autonomic responsivity. In other animal studies, autonomic activation is reduced or absent in experienced, successful aggressors (Potegal, 1994). In trying to accommodate such results, Schachter (1964) suggested that autonomic arousal might be essential to anger but not to aggressive behavior. The question as to whether emotions emerge from central brain processes or from peripheral arousal and somatic changes appears to be inappropriate in the presence of modern research (Traue & Pennebaker, 1993). Antagonistic excitatory and inhibitory systems Early formulations of arousal led to the development of a three-component nervous system (Gray, 1979): a nonspecific arousal system, a behavioral inhibitory system, and a behavioral activation system. The behavioral inhibition and activation systems interact with each other in an antagonistic manner and both have positive input into the third nonspecific arousal system, anatomically identified with the reticular formation. Without going into the details of the neurophysiological experimentation, several areas can briefly be mentioned which have been implicated as antagonistic excitatory and inhibitory systems related to aggression and arousal. On the behavioral side, the ventromedial hypothalamus inhibits motor neurons and the lateral hypothalamus has excitatory effects (Potegal, 1994). Both these hypothalamic areas are connected to fibers ascending from the reticular arousal system and antagonistic areas in the amygdala. Likewise, descending fibers from the dorsal septal region and from the dorsal hippocampus are associated with inhibition. Laborit (1993) reviewed the numerous experimental findings that suggest that the inhibitory system, mediated by acetylcholine and serotonin, triggers the hypothalmo-pituitary-adrenal cortex reaction and the peripheral sympathetic reaction to aggression. In the hierarchy, each behavioral system appears to be supraordinate to a separate set of core, affective systems: the dopamine system for positive affect and the noradrenergic for negative emotions (Leventhal, 1991). The dopaminergic and noradrenergic components of the central and autonomic nervous system appear to be the functional trigger units for the processing of behavioral approach and avoidance. Data at the cellular level show that noradrenergic neurons in mammals such as cats are activated in response to a wide range of stimuli, from the presence of a dog through white noise to fever (Wise, 1988). The affective systems are sensitive to a particular range of inputs and have well-defined effects on response output—ranging from attention changes and learning to attack or escape. The subcortical system impacts on higher levels, the feeling that people are capable and in control is undercut by high levels of arousal. When people feel angry, higher cognitive processes are being overwhelmed (Tyson, 1982). The reciprocal and intimate relationship of arousal to cognition means that peoples’ plans and behaviors are often in the service of reducing arousal.

The diversity of professions offering perspectives or explanations for aggression point to the multidimensional complexity of the subject (Baron & Richardson, 1994). Heightened arousal contributes to episodes of reactive aggression, but physiological variables by themselves cannot explain the current escalation of violence in North America. As Tuchman (1978) has pointed out, historical periods of increased aggressiveness are usually associated with a growth of egocentricity at the expense of altruism, an erosion of personal responsibility and the utilization of physical violence as an instrument of enforcing government policy. If an individual is predisposed by past experience and situational factors to act aggressively, intense physiological arousal can increase the probability of his/her dominant response. Heightened arousal produces cognitive overload, motivates a person to reduce arousal and reinforces behaviors, whether aggressive or nonaggressive, that accomplish the result. The overwhelmed person closes down his/her system, reducing attention to mitigating circumstances and disrupting cognitive control over impulsive behavior. Relaxation allows the system to open both internally and externally, receiving and processing more information as the person’s heightened arousal levels are attenuated (Tyson, 1982). The thesis of this article is that interventions designed as deterrents to reactive aggression must induce positive affect and lower arousal as incompatible responses to anger and overt aggression. Although it seems impossible to eliminate aggression by desensitizing people to all stimulus situations eliciting aggressive behavior, teaching relaxation can reduce physiological arousal, allowing people time to think before they attack. Moving toward optimal arousal levels, behavioral responses become less automated by past experience and cognitive processes can moderate aggressive behavior. People will not restrain themselves, even if they become aware of their heightened arousal, unless they believe that it is inappropriate to be aggressive in the situation and that they are capable of controlling their aggressive arousal.