健康与遗传心理学研究室知识库

认知系统的一个核心功能是对自身行为所导致的结果或外界反馈进行快速评价，从而采取相应的对一策改善我们的行为，这一过程就是结果评价(Outcome Evaluation )。它对人类认知发展以及多种认知能力和技巧的形成都有着重要的作用。目前，对结果评价过程方面的研究已经成为认知神经科学领域的热点问题。已有的ERP研究已经发现很多结果评价行为都伴随着反馈负波(feedback negativity, FN)和P300成分的出现，而相关的fMRI研究则发现，前额叶皮层(prefrontal Cortex,  PFC )，尤其是扣带前回(Anterior Cingulate Cortex, ACC)在结果评价过程中起重要作用。
然而，到目前为止，关于FN和P300的认知和神经加工机制仍然不清楚;而且，结果评价过程的认知神经研究主要是基于一些较为简单的任务(比如简单判断任务和简单赌博任务)的研究，而很少有关于复杂的认知任务的研究。
在本研究中，我们采用了三种相对复杂的认知任务，即欺骗，复杂赌博，以及猜谜，并且选择了将纵向深入的递进式研究和横向展开的比较研究结合起来的研究方法，试图揭示结果评价过程的神经机制。首先，我们以一个研究任务(欺骗)作为突破口，由浅入深，由简入繁地进行了三个纵向实验，分别对简单反应行为:简单欺骗行为和复杂的交互式欺骗行为中结果评价的ERP相关成分进行了研究。然后，我们又从横向对比的角度对赌博行为中结果评价的神经机制以及猜谜行为中结果评价的神经机制两个问题进行了研究，将它们的结果与欺骗行为的结果进行横向比较。研究结果发现:
1)不同任务以及有奖赏和无奖赏的结果评价加工都伴随着FN和P300的出现，说明FN和P300是与结果评价加工有关的两个基本ERP成分。偶极子源定位分析显示，FN起源于ACC背侧尾部，而P300的起源靠近ACC的嘴侧。 
2 ) FN和P300在功能上表现出明显的认知和情绪的分离现象:FN反映的是一种作出反应以后实际结果与期望不一致时的认知冲突加工，而P300反映的是对结果刺激的情绪评价加工，并且P300波幅的高低与被试自己的情绪体验强弱有关。
3)期望和动机对结果评价过程中的冲突成分和情绪成分有着重要影响，这种影响也主要表现在FN和P300上。总的来说，任务越复杂，被试的期望和动机越强，结果评价阶段所产生的认知冲突和随后的情绪体验也越强。
本研究具有重要的理论意义和现实意义。在理论意义上，结果评价阶段是人类认知行为中重要的组成部分，对其神经机制的研究对相关的决策、反馈和其他社会认知研究都有着重要的影响;在现实意义上，欺骗、赌博和猜谜等是人类社会生活中常见的行为，对它们的脑机制研究对我们理解和分析人类行为有着重要意义，在教育和经济领域都有十分重要的应用价值。

A central function of the cognitive system is to provide rapid evaluations of outcome of our behavior or feedback stimuli in our environment, and then take strategy to improve our action. Outcome evaluation plays an important role in human cognitive development and formation of many cognitive abilities and skills. The research on outcome evaluation has recently been the hotspot in the field of cognitive neuroscience. Previous studies have identified two ERP correlates of outcome evaluation processing, feedback negativity (FN) and P300. And fMRI studies have found that prefrontal cortex (PFC), especially anterior cingulated cortex (ACC), involves in the processing of outcome evaluation.
However, the nature of the evaluative process reflected in the FN and P300 remains unknown till now. In addition, studies on the neural basis of outcome evaluation processing mainly based on some simply tasks, such as simply decision task and gamble task, and there is few research on complex cognitive tasks.
  In the present study, we attempted to reveal the neural basis of outcome evaluation processing by combining transverse comparison and lengthways in-depth study, using three comparatively complex cognitive tasks (e.g., deception, gamble, and riddle-guessing task).First, we explored the ERP correlates of outcome evaluation in the simple response behavior,simple deception behavior and complex mutual deception behavior by design three experiments from surface to deep, simple to complex. Then, we studied the neural basis of outcome evaluation in gambling behavior and riddle-guessing behavior from the point of view of transverse comparison, and compared the results of them from that of deception behavior. The main findings are showed in the following:
1) FN and P300 can be observed in different tasks including the stage, of outcome       evaluation, no matter whether the outcome is or not reward-related, which might suggest that they are two fundamental ERP components related to outcome evaluation processing. Dipole source localization analysis showed that the neural generator of FN is the caudal-dorsal ACC, and the generator of P300 is closed to the rostral ACC.
2)There is a functional dissociation between FN end P300. FN might reflect cognitive  conflict  when  the  actual  outcome  is  different  from  people's expectation for the outcome of their actions. P300 is related to the emotion processing of outcome stimuli we encounter after we take action, and its amplitude may reflect the degree of emotion we experience.
3)Expectation and motivation have important influence on the cognitive conflict and emotion component in outcome evaluation, which can be found in FN and P300. In general, the more complex the task and the stronger the expectation and motivation of subjects, the stronger the cognitive conflict and experienced emotion in outcome evaluation.
  The present study has important theoretic and practical significance. For the theoretic significance, outcome evaluation is an important part of human cognitive behavior, and research on it will have important influence on making decision, feedback and other social cognitive studies; as to the practical significance, gambling, deception and guessing riddles play an important role in people's everyday life, and therefore studies on their neural basis are very useful in our .understanding and analyzing human behavior, and has important application value in education psychology and economic field.