Cognitive performance,monetary incentive,and aggression

Individuals with impaired cognitive abilities associated with frontal lobe function have recently been shown to manifest increased aggression. This study investigated the effect of contingent money to inhibit aggression in these individuals. One hundred and forty males, aged 18–40, were ranked according to their performance on the Spatial Conditional Associative-Learning task. Forty-eight males (24 with scores in each of the upper and lower performance quartiles) participated in the full study. Half of the subjects competed in a Taylor aggression task where they received a monetary incentive for choosing lower shocks; the remainder competed without any monetary contingency. Aggression was defined as shock intensity delivered to a sham opponent. Shock intensity significantly increased as a main effect of lower cognitive performance, absence of monetary incentive, and provocation. In addition, provocation interacted significantly with test performance. Finally, individuals in the upper cognitive performance quartile showed significantly greater reductions of unprovoked aggression in response to monetary incentive. The results are discussed in terms of impairments in the ability to associate inhibitory influences in the formulation of behavioral strategies under aggressive conditions. © 1996 Wiley-Liss, Inc.     

风险决策的神经机制:基于啮齿类动物研究

风险决策是在不同选项的结果确定、并且结果出现的概率已知情况下的决策。啮齿类风险决策模型研究发现前额皮层-杏仁核-伏隔核神经环路联系是决定风险决策的选择倾向的关键。前额皮层中的眶额皮层和内侧前额皮层参与风险决策的策略形成和策略转换有关;而皮层下核团中的杏仁核、腹侧纹状体的伏隔核等结构参与策略保持、价值判断,影响决策偏向和行动强度;眶额皮层、伏隔核神经元和多巴胺神经元编码风险决策过程中的概率、风险等因素;此外,多巴胺等单胺类神经递质及受体在风险决策中有复杂的作用。     

关联记忆的神经机制研究述评

关联记忆与来源记忆存在很多相似之处,但也存在一定的差异。与项目记忆相比,关联记忆需要参与的大脑区域相对较多,包括前额区与海马等;电生理研究、成像研究以及病人研究都为这一观点提供了可靠的证据。     

Conflict and Cognitive Control in the Brain

ABSTRACT— Recent research from cognitive psychology and cognitive neuroscience has suggested that the control mechanisms by which people are able to regulate task performance can be dissociated into evaluative and executive components. One process, implemented in the anterior cingulate cortex of the brain, monitors the amount of conflict that occurs during information processing; another process, implemented in the dorsolateral prefrontal cortex, is involved with maintaining the requirements of the task at hand and with biasing information processing in favor of appropriate responses. In the current article, we review this theory and some of the research that has supported it, including its implication for understanding cognitive disturbances in clinical disorders such as schizophrenia and obsessive-compulsive disorder. We conclude by addressing several interesting possibilities for future research.     

Muscarinic cholinergic receptor blockade in the rat prelimbic cortex impairs the social transmission of food preference

Previous findings demonstrate the involvement of the cholinergic NBM in the acquisition of the social transmission of food preference (STFP), a relational associative odor-guided learning task. There is also evidence that muscarinic receptors in the medial prefrontal cortex, an important NBM target area, may modulate olfactory associative memory. The present experiment determined the consequences of blocking muscarinic cholinergic receptors in a component of the medial prefrontal region (the prelimbic cortex) on the STFP task. Adult male Wistar rats were bilaterally infused with scopolamine (20 microg/site) prior to training and showed a severe impairment in the expression of the task measured in two retention sessions, both immediately and 24h after training. Local scopolamine injections in the prelimbic cortex did not affect other behavioral measures such as olfactory perception, social interaction, motivation to eat, neophobia, or exploration. Results suggest that muscarinic transmission in the prelimbic cortex is essential for the STFP, supporting the hypothesis that ACh in a specific prefrontal area is important for this naturalistic form of olfactory relational memory. Current data are discussed in the context of disruption of learning as a result of interferences in PLC functions such as behavioral flexibility, attention, and strategic planning.