An Event Related Brain Potential Analysis of Affect and Attitudes

自我报告和行为措施的态度和说服过程依赖于二价的行动处置引起的态度刺激，尽管反应扭曲的潜力。 当外周躯体内脏措施已被用来调查沟通和态度，调查人员传统上试图确定的反应，固有的特定情感状态。 躯体内脏反应的多种决定因素以及内在生理反应和特定情感状态之间的脆弱联系，极大地限制了先前对态度进行生理评估的有用性。 而不是依赖于反应处置或外围生理反应，拟议的研究利用事件相关脑电位（ERP）和分类过程的后期积极成分之间的关系更强大的态度现象进行研究。在这种方法中，受试者的态度作为标准，沿着哪些刺激被分类，而ERP记录。 在迄今为止的研究中，已经发现ERP中的晚期正电位（LPP）作为受试者对目标刺激的态度与他们对目标刺激之前的刺激的态度之间的差异的函数而变化。 因此，嵌入在非常积极（消极）的刺激的短序列中的态度刺激越消极（积极），在中央顶叶头皮区域上的晚期正电位（LPP）幅度越大（Cacioppo，Crites，Berntson，Coles，1993; Cacioppo，Crites，Gardner，Berntson，1994）;即使当明显或口头反应不能准确反映受试者的态度时，也发现了这种关系（Cacioppo等人，1993; Crites，Cacioppo，Gardner，Berntson，1995），并且这种关系概括了性别、一年中的季节、头部大小、简单恐惧症状态和实验（语义、图像）刺激（Cacioppo等人，1993，1994; Crites等人，1995; Gardner，Cacioppo，Crites，Berntson，1995）。这些结果表明，LPP振幅在这个范例中反映了态度分类（与反应选择或执行）的过程。 最后，五个不同的研究结果表明，LPP幅度是大于左半球的标准时，受试者的态度作为沿着哪些刺激被归类;当受试者执行语义而不是评价性分类任务，相反，LPP幅度是不偏侧化（Cacioppo，Crites，加德纳，Berntson，正在审查; Crites，1994年）。 本研究的主要目的是利用事件相关电位来检验Cacioppo和Berntson（1994）的评价空间模型中关于情感组织和加工的假设，并将这些预测与情感组织的环形模型进行对比。 态度和说服过程的自我报告和行为测量依赖于双极测量（例如，“同意”到“不同意”）。 这些措施不仅容易受到反应扭曲的影响（例如，但他们也无法区分那些对刺激或决定持中立态度的人与那些感到矛盾或冲突的人。 例如，对滥用药物或酒精既不感到积极也不感到消极的人不能与对药物或酒精既感到强烈积极又感到强烈消极的人区分开来（例如，上瘾的人）。 然而，这些群体的人开始或继续吸毒或酗酒的原因大不相同。 在目前的研究中，我们继续致力于开发一种基于大脑的态度和潜在动机基础的测量方法，（1）不要求个人愿意准确地报告他们的感受 关于人、物体或问题;（2）不仅区分态度和决定背后的积极和消极动机，而且区分每种动机基质的力量（强度）。 在这种方法中，受试者的态度作为标准，沿着哪些刺激被分类，而事件相关脑电位（ERP）被记录。在迄今为止的研究中，已经发现ERP中的晚期正电位（LPP）作为受试者对目标刺激的态度与他们对目标刺激之前的刺激的态度之间的差异的函数而变化。 因此，越消极（积极）， 嵌入在短序列的非常积极（消极）的刺激的态度刺激，较大的晚正电位（LPP）的幅度在centroparietal头皮区域;这种关系被观察到，即使 当明显的或口头的反应不能准确地反映一个主题的态度。在接下来的两年里，这项研究的主要目标是使用ERP来对比情感组织和处理的竞争理论模型，以更好地理解生产性和反生产性决策和行为背后的心理和大脑机制。

Self-report and behavioral measures of attitudes and persuasion processes have relied on the bivalent action disposition aroused by the attitude stimulus despite the potential for response distortion. When peripheral somatovisceral measures have been used to investigate communication and attitudes, investigators have traditionally sought to identify responses that were inherently linked to specific affective states. The multiple determinants of somatovisceral responses and the tenuous links between inherent physiological responses and specific affective states have placed strong limits on the usefulness of prior physiological assessments of attitudes. Rather than relying on response dispositions or peripheral physiological responses, the proposed research exploits a more robust relationship between the late positive component of the event-related brain potential (ERP) and categorization processes to study attitude phenomena. In this approach, a subject's attitude serves as the criterion along which stimuli are categorized while ERPs are recorded. In research to date, a late positive potential (LPP) in the ERP has been found to vary as a function of the discrepancy between subjects' attitude toward a target stimulus and their attitude toward the stimuli that preceded the target stimuls. Thus, the more negative (positive) the attitude stimulus embedded within a short sequence of very positive (negative) stimuli, the larger a late positive potential (LPP) amplitude over the centroparietal scalp region (Cacioppo, Crites, Berntson, & Coles, 1993; Cacioppo, Crites, Gardner, & Berntson, 1994); this relationship was found even when overt or verbal responses did not accurately reflect a subject's attitude (Cacioppo et al., 1993; Crites, Cacioppo, Gardner, & Berntson, 1995), and this relationship generalizes across gender, seasons of the year, head sizes, simple phobia status, and experimental (semantic, pictorial) stimuli (Cacioppo et al., 1993, 1994; Crites et al., 1995; Gardner, Cacioppo, Crites , & Berntson, 1995). These results suggest that the LPP amplitude in this paradigm reflects attitude categorization (in contrast to response selection or execution) processes. Finally, the results of five different studies indicate that the LPP amplitude is larger over the right than left hemisphere when a subject's attitude serves as the criterion along which stimuli are categorized; when subjects perform a semantic rather than an evaluative categorization task, in contrast, the LPP amplitude is not lateralized (Cacioppo, Crites, Gardner, & Berntson, under review; Crites, 1994). The primary goal of the proposed research is to use ERPs to test hypotheses regarding affective organization and processing from Cacioppo and Berntson's (1994) model of evaluative space and to contrast these predictions with those made by the circumplex model of affective organization. Self-report and behavioral measures of attitudes and persuasion processes have relied on bipolar measures (e.g., "agree" to "disagree"). These measures are not only susceptible to response distortions (e.g., lying) but they also fail to differentiate individuals who feel neutrally about a stimulus or decision from those who feel ambivalent or conflicted. For instance, individuals who feel neither positive nor negative about abusing drugs or alcohol cannot be differentiated from those who feel both strongly positive and strongly negative about drugs or alcohol (e.g., a remorseful addict). The reasons for the onset or continuation of drug or alcohol abuse, however, differ dramatically between these groups of individuals. In the current research, we continue work on developing a brain-based measure of attitudes and underlying motivational bases that (1) does not require that individuals be willing to report accurately how they feel about persons, objects, or issues; and (2) differentiates not only between the positive and negative motivations underlying attitudes and decisions but also the force (intensity) of each motivational su bstrate. In this approach, a subject's attitude serves as the criterion along which stimuli are categorized while event related brain potentials (ERPs) are recorded. In research to date, a late positive potential (LPP) in the ERP has been found to vary as a function of the discrepancy between subjects' attitude toward a target stimulus and their attitude toward the stimuli that preceded the target stimuls. Thus, the more negative (positive) the attitude stimulus embedded within a short sequence of very positive (negative) stimuli, the larger a late positive potential (LPP) amplitude over the centroparietal scalp region; this relationship is observed even when overt or verbal responses do not accurately reflect a subject's attitude. The primary goal of the research to be conducted over the next two-year period is to use ERPs to contrast competing theoretical models of affective organization and processing to better understand the psychological and cerebral mechanisms underlying productive and counterproductive decisions and behaviors.