Project 4: Trait Fear and Fearlessness in Humans (pg 229)

人们越来越感兴趣的是将人格和精神病理学的维度映射到 生物系统。恐惧是这方面的一个关键结构，因为它代表了一个维度， 人类变异具有直接的生物学意义和明确的心理健康影响。广大 这项研究的目的是探讨在儿童中， 人类参与者，并检查与恐惧个体差异相关的大脑机制 反应性这项工作的基础是先前的研究表明，在恐惧增强 在被监禁的精神病患者中感到震惊，他们被概念化为无所畏惧。 最近的研究显示，在无畏的社区参与者中也有类似的障碍。 支配，一种与精神病相关的结构，作为特质恐惧的低极点指标。三 为了扩大这项工作，建议分阶段进行研究，其目的如下：（1） 将从一个大型社区双胞胎那里收集特质恐惧和无所畏惧的心理测量指标 样本来评估遗传和环境对潜在恐惧维度的贡献;（2） 这些双胞胎将在实验室中进行测试，以确定恐惧增强惊吓作为这一标志。 潜在的特质恐惧维度，并确定这种关联的病因学基础;（3）双胞胎 选择在特质恐惧分数和恐惧增强惊吓水平上都低或高的配对， 在一项神经成像（fMRI）研究中进行了测试，以研究与以下因素相关的大脑反应性差异： 特征恐惧的变化，并产生线索，这些差异的病因。这项研究将 有助于我们理解特质恐惧和无畏的生物学基础， 人类，并与此相关，先进的概念化和测量的结构， 与人格和精神病理学的根本关联

There is increasing interest in mapping dimensions of personality and psychopathology onto biological systems. Fear is a key construct in this regard because it represents a dimension of human variation with direct biological significance and clear mental health implications. The broad objective of the proposed research is to explore etiologic contributions to trait fear and fearlessness in human participants and to examine brain mechanisms associated with individual differences in fear reactivity. A foundation for this work is prior research demonstrating impairments in fear-potentiated startle among incarcerated psychopathic individuals, who have been conceptualized as fearless. More recent research has revealed similar impairments in community participants high in Fearless Dominance, a psychopathy-related construct that acts as a low pole indicator of trait fear. Three phases of research are proposed to extend this work, with the following aims in mind: (1) Psychometric measures of trait fear and fearlessness will be collected from a large community twin sample to evaluate genetic and environmental contributions to a latent fear dimension; (2) A subset of these twin pairs will be tested in the laboratory to establish fear-potentiated startle as a marker of this underlying trait fear dimension, and to determine the etiologic basis of this association; and (3) Twin pairs selected to be low or high on both trait-fear scores and level of fear-potentiated startle will be tested in a neuro-imaging (fMRI) study to investigate differences in brain reactivity associated with variations in trait fear, and to yield clues as to the etiology of these differences. This research will contribute to our understanding of the biological underpinnings of trait fear and fearlessness in humans, and in connection with this, advance conceptualization and measurement of a construct of fundamental relevance to personality and psychopathology.