Cognitive Bases of Risk-taking Over the Lifespan: Psychophysics & Brain Imaging

描述（由申请人提供）：我们对风险的态度几乎决定了我们行为的方方面面。它会影响我们服用滥用药物的意愿，影响我们进行有效的金融投资的意愿，影响我们在医疗保健方案中做出选择的意愿。我们知道，这些态度会随着人的一生而改变，随着年龄的增长，这些变化会使我们在不同方面变得脆弱。青少年的危险行为大大增加了他们的死亡率。年长者通常表现出相反的形象，避免冒险行为。但是，随着年龄的增长，我们的行为会发生什么变化呢？哪些特定的行为倾向和衰老的神经生物学特征可以解释我们对风险态度的变化？在这个应用中，我们建议结合经济学、心理学和神经生物学的方法来研究风险行为，努力在行为和神经水平上描绘出一生中风险态度的画像。行为经济学分析表明，冒险行为源于对风险的三种基本独立的态度：(1)技术性风险厌恶，反映了收益或损失的概率与收益和损失的大小之间的权衡；(2)模糊性厌恶，反映了主体对不确定性的敏感性；(3)损失厌恶，反映了主体对损失和收益的差异敏感性。我们假设，在整个生命周期中，被广泛观察到的冒险行为的减少主要是由于模糊厌恶的增加，而不是风险或损失态度的增加。此外，我们假设，如果有的话，随着年龄的增长，人类应该在技术上变得不那么厌恶风险和损失。在神经层面上，我们也知道大脑发育中有明确的结构模式，这些模式很可能是整个生命周期中观察到的行为变化的基础。对我们的假设特别感兴趣的是观察到额叶区域成熟较晚，实际上在发育过程中变薄，实际上在整个生命周期中持续变薄。前额皮质决策区的激活模式也会在整个生命周期中发生变化。这些数据表明，额叶皮层的形态和功能特性可能会影响一生中风险相关行为的变化，我们建议使用行为和功能成像技术的混合来验证这一假设。

DESCRIPTION (provided by applicant): Our attitude towards risk shapes nearly every aspect of our behavior. It affects our willingness to take drugs of abuse, to make efficient financial investments, and to select amongst healthcare options. We know that these attitudes change over the lifespan and that these changes make us vulnerable in different ways as we age. Adolescents engage in risky behaviors that hugely increase their mortality rates. Elders typically show the opposite profile, avoiding risky behaviors to a fault. But what is it about our behavior that changes as we age? What specific behavioral propensities and neurobiological features of aging can account for the changing attitudes we take towards risks? In this application we propose to combine economic, psychological and neurobiological approaches to the study of risky behavior in an effort to paint a portrait of risk attitudes across the lifespan at the behavioral and neural levels. Behavioral economic analyses suggests that risk-taking behavior results from the three largely independent attitudes towards risks: (1) Technical risk-aversion, which reflects a trade- off between the probability of gains or losses and the magnitude of those gains and losses, (2) Ambiguity aversion, which reflects the subject's sensitivity to uncertainty, and (3) Loss aversion, which reflects a subject's differential sensitivity to losses and gains. We hypothesize that the reduction in risk-taking behavior across the lifespan that is widely observed is primarily due to an increase in ambiguity aversion, rather than to an increase in risk or loss attitudes. Further, we hypothesize that, if anything, humans should become less technically risk averse and loss averse as they age. At the neural level, we also know that there are clear structural patterns in brain development that may well underlie these behavioral changes observed across the lifespan. Of particular interest to our hypothesis is the observation that frontal regions mature late, actually thinning during development and actually continue to thin throughout the lifespan. Activational patterns fronto-cortical decision areas also change throughout the lifespan. These data suggest that both morphologic and functional properties of the frontal cortex may contribute to these changes in risk-related behavior over the lifespan, a hypothesis we propose to test with a mixture of behavioral and functional imaging techniques. PUBLIC HEALTH RELEVANCE: Our attitude towards risk shapes nearly every aspect of our behavior, including our willingness to take drugs of abuse, to make efficient financial investments, and to select amongst healthcare options. We know that these attitudes change over the lifespan and that these changes make us vulnerable in different ways as we age. We propose an analysis of the precise behavioral and neural basis of risk attitudes across the lifespan in an effort to better understand the neural basis of behaviors such as drug abuse, adolescent risk-taking, and healthcare decision-making.