【作者】 张健；

【导师】 韩玉昌；

【作者基本信息】 辽宁师范大学 ， 发展与教育心理学， 2013， 博士

【摘要】 决策是一种高级认知加工活动,普遍存在于人们的行为中。决策过程中的理性与非理性是决策理论争论的一个热点。决策过程中的框架效应体现了问题表述对理性决策的干扰,意指当决策问题的表述发生改变时,决策选择发生反转的现象。以往研究对风险决策框架给予了高度关注,然而缺乏对其他类型决策框架以及框架效应影响因素的探讨。本研究综合使用问卷调查、ERP技术、LORETA源定位方法等研究手段,首先从不同认知风格被试处理不同类型决策框架信息时的行为反应入手,进而探讨当决策问题信息以不同方式呈现时,场依存者和场独立者在决策加工过程中的认知活动及神经机制。实验分析N200成分和P300成分的平均波幅和潜伏期,以及相应的大脑活动来源。研究发现,对于不同认知风格被试,大脑左半球的N200平均波幅和P300平均波幅均显著低于右半球。当决策问题信息以语言文字的方式呈现时,场依存者的N200平均波幅和P300平均波幅均显著低于场独立者；当决策问题信息以图形方式呈现时,没有发现场依存者和场独立者在N200平均波幅和P300平均波幅上的显著差异。采用LORETA源定位对N200和P300的大脑活动来源进行的分析发现,大脑额叶和顶叶的多个区域参与了决策的认知加工。结合以往研究和本研究的实验结果,得到以下几点结论：(1)认知风格与框架效应具有显著相关关系。与场独立者相比,场依存者更容易产生框架效应。(2)当决策问题信息以语言文字这一传统方式呈现时,场依存者和场独立者在行为反应时、N200平均波幅、P300平均波幅上均存在显著差异。与场依存者相比,场独立者在决策刺激的最初辨别和随后的信息评价过程中投入了更多的认知加工。(3)当决策问题信息以图形方式呈现时,场依存者和场独立者的决策加工过程表现出了相似的早期加工特点和行为反应特点。但在对刺激信息进行认知评价时,与场依存者相比,场独立者对决策问题信息分配了更多的注意资源,并进行了更深入的认知加工(4)决策问题信息的呈现方式不仅影响决策者的决策行为和大脑活动,而且这一影响可以一定程度地掩盖场依存者和场独立者之间加工过程的差异。(5)大脑右半球在认知决策过程中起到了重要作用。无论场依存者还场独立者,在对决策问题信息的早期辨别加工和随后的认知评价中都表现出了大脑右半球的加工优势。(6)决策问题的呈现方式影响大脑活动的时间进程。当决策问题信息以文字呈现时,决策者对刺激信息的加工起始于左半球,然后转向右半球并在右半球完成加工。当决策问题信息以图形呈现时,决策者对刺激信息的认知加工起始于右半球,然后转向左半球,并在左半球中完成加工过程。(7)对N200成分和P300成分进行的大脑活动来源的分析发现,决策加工激活的脑区分布在额叶和顶叶的多个区域,包括额上回、额中回、顶叶后中央回、舌回,涵盖了BA6, BA7, BA18等区域。该结果与以往采用脑成像方法的研究相吻合,表明额叶和顶叶在决策过程中起到了重要作用。更多还原

【Abstract】 As an advanced cognitive activity, decision-making exists in human daily life. In the pastfew decades, the rationality of the decision-making process has sparked enormous interestwithin the fields of psychology and also economy. In the contrast to the axiom of descriptionof invariance, vast numbers of reports in the literature and results from research haveindicated that people often deviate from responses considered as being normative in manyjudgemental and decision-making tasks, which is also known as framing effect indecision-making that different representations of the same problem do not yield the samepreference or choice. Traditional research in framing effects has commonly and mainly beenfocused on risky choice framing effect, whereas the research on other types of framing effectand the influential factors seems to be lacking. Therefore, the current study has utilizedquestionnaire, ERP technology, LORETA souce localization technology and other techniquesto further investigate the differences of cognitive activities and neuromechanism betweenindividuals with field-dependent cognitive style and field-independent cognitivelyrespectively, starting with the distinctions in behavioural responses that individual withdifferent cognitive styles may have. Results from the analysis of the brain activities and theaverage amplitude and latent period of N200and P300in the present study illustrate that theaverage amplitudes of N200and P300in the left hemisphere are significantly lower than theright hemisphere, regardless of the cognitive styles. Furthermore, in the situation where thedecision tasks have utilized verbal scenarios, the average amplitudes of N200and P300inparticipants with field-dependent cognitive style are remarkably lower than thefield-independent individuals; thereagainst, in the situation where decision problem isexhibited with graphical representations, no outstanding difference on the average amplitudesof N200and P300has been found between individuals with the two different cognitive styles.The manipulation of LORETA source localization technology on the source of N200andP300in the brain activities has revealed that multi region in the brain, such as the frontal lobeand parietal lobe, are involved in the cognitive processing in decision-making.To integrate the research results of the present study with previous research, severalconclusions can be drawn:The representations of the decision task can impact on people’s decision behaviour andbrain activity, simultaneously, the impact can somehow conceal the differences in cognitiveprocessing caused by cognitive style itself between people with field-dependent cognitivestyle and field-independent cognitive style.When the decision tasks are represented utilizing verbal scenarios, the average amplitudes of N200and P300and response time are significantly different betweenindividuals with the two cognitive styles, known as field-dependent and field-independent.Additionally, comparing with individuals with field-dependent cognitive style, individualswith field-independent cognitive style put extra cognitive processing into the initialassessment and feedback process afterwards.In the situation where the decision problems are demonstrated using graphicrepresentations, similar early processing and behaviour features have been found in thecognitive process in decision-making between people with field-dependent cognitive style andfield-independent cognitive style. Furthermore, more attentional resources and furthercognitive processing have been assigned to the information of the decision questions inindividuals with field-independent cognitive style, rather than individuals withfield-dependent cognitive style.The right hemisphere has been proved to play a vital role in the cognitive processing ofdecision-making, and the right-hemisphere dominance in early evaluation process and later-oncognitive assessment has been found in people with both field-dependent cognitive style andfield-independent cognitive style.The representations of decision problem can alter the time course of brain activities.Specifically, when the representations are verbally, decision-makers’ cognitive processing ofstimuli start from the left hemisphere and gradually transfer towards the right hemisphere,which finalized in the right hemisphere. Nevertheless, when the decision problem aredescribed using graphical representations, decision-makers’ cognitive processing of thestimuli start from the right hemisphere and shift to the left hemisphere, then completed theprocessing there.Results of source localization analysis on the brain activities of N200and P300indicatethe several areas in the frontal lobe and parietal lobe have been activated by the cognitiveprocessing of decision-making, including superior frontal gyrus, middle frontal gyrus,post-central gyrus, and lingual gyrus, which comprise BA6, BA7, BA18and other regions.This result is consistent with the findings from previous cerebral imaging studies, whichimplied the vital role that frontal lobe and parietal lobe played in the decision-making process.更多还原