Psychophysiological study of "expectancy" and "cognitive map"

“期望”和“认知地图”是新行为主义者托尔曼理论中关于认知功能的重要概念，受到了许多认知科学家和认知神经科学家的重新关注。本研究旨在探讨这些概念的神经元机制。在实验中，这只动物被训练通过使用几种食物和液体奖励来执行“延迟反应”和“延迟反应时间”任务。根据正确的反应，氨基被加强或不加强，在每次试验开始时，动物被告知奖励的存在或不存在，或者应该给予或不应该给予的奖励。研究发现，灵长类动物的前额叶皮层中有一些神经元被认为与“对特定奖励的期望”有关，也有一些神经元与“对没有特定奖励的期望”有关。这只动物接受了这两种任务（延迟反应和延迟反应时间）的几个不同版本的训练。研究发现，灵长类动物前额叶皮层中存在着神经元，随着任务情境的不同，神经元的活动变化幅度不同或模式不同。这些神经元被认为与监测任务情境有关。最近对前额叶皮层的研究主要集中在工作记忆控制行为的机制上。目前的研究表明，前额叶皮层在监测动物所面临的环境中也起着重要的作用。

"Expectancy" and "cognitive map", which were important concepts concerning the cognitive function in the theory of neobehaviorist Tolman, have gained revised attention by many cognitive scientists and cognitive neuroscientists. The present study was conducted to investigate neuronal mechanisms of these concepts.In the experiment, the animal was trained to perform "delayd response" and "delayd reaction time" tasks by using several kinds of food and liquid rewards. The aminla was reinforced or not reinforced for its correct response, and at the begining of each trial the animal was informed of the presence or absence of the reward, or the kind of reward which should be given or should not be given. It was found that there are neurons in the primate prefrontal cortex which are considered to be involved in the "expectancy of the specific reward" as well as those which are involved in the "expectancy of the absence of the specific reward".The animal was trained on several different versions of the two kinds of tasks (delayd response and delayd reaction time). It was found that there are neurons in the primate prefrontal cortex which showed different magnitude of, or different pattern of, activity changes depending of the difference of the task situation. These nuerons are considered to be related to monitoring the context of the task situation.Recent studies of the prefrontal cortex have concentrated on the mechanisms of working memory in the control of behavior. The present study indicates that the prefrontal cortex plays important roles also in monitoring the context were the animal is faced with.