Effects of stress on motivated behavior: Age differences and neural mechanics

压力对动机行为的影响：年龄差异和神经机制

• 批准号: 8262393
• 负责人: Nichole Lighthall
• 金额: $ 1.41万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2012-08-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8262393
• 关键词: Address; Affect; Age; Aging; Animal Model; Automobile Driving; Avoidance Learning; Behavior; Behavioral; Brain; Brain region; Cerebrovascular Circulation; Cognition; Cognitive; Complex; Corpus striatum structure; Data; Decision Making; Dopamine; Economics; Elderly; Feedback; Frequencies; Functional Magnetic Resonance Imaging; Goals; Healthcare; Human; Hydrocortisone; Impairment; Incentives; Individual; Insula of Reil; Intervention; Investments; Lateral; Learning; Life; Literature; Longevity; Measures; Mechanics; Mediating; Motivation; Neurocognitive; Neurosecretory Systems; Outcome; Participant; Pathway interactions; Performance; Play; Preparation; Process; Psychological reinforcement; Punishment; Research; Rest; Rewards; Risk; Risk Behaviors; Role; Salivary; Selection Bias; Short-Term Memory; Signal Transduction; Stimulus; Stress; Structure; Testing; Time; acute stress; age difference; age group; age related; base; biological adaptation to stress; cognitive function; design; dopamine system; dopaminergic neuron; experience; hypothalamic-pituitary-adrenal axis; improved; insight; meetings; motivated behavior; neuroimaging; neuromechanism; neurophysiology; normal aging; novel; public health relevance; reinforcer; relating to nervous system; response; reward processing; young adult

DESCRIPTION (provided by applicant): Stress is common in everyday life and appears to alter learning and decision making involving potential rewards and punishments. This finding that may be attributed to stress-induced enhancements of dopamine system activity. Due to age-related changes to brain structure and function, however, the impact of stress is likely to differ for younger and older adults. The long-term objective of this research is to understand how stress impacts the neural mechanisms of motivated behavior across the lifespan. This research may be used to determine older adults' ability to manage economic decisions and develop interventions targeted at addressing the needs of older adults experiencing stress. The overall aim of the proposed research is to determine the mechanisms driving effects of acute stress on learning involving rewarding and aversive feedback in normal aging. The proposed study will address these specific aims: 1) examine how acute stress affects response to positive and negative feedback, 2) examine how acute stress affects learning involving positive and negative incentives, and 3) identify the brain regions responding to acute stress via change in cerebral blood flow (CBF) from control to stress conditions. The central hypothesis of this study is that stress will exert different effects on brain regions responsible for feedback-learning in younger and older adults, but will selectively enhance the salience of rewarding outcomes in both age groups. To address these objectives, the proposed study will use functional neuroimaging to investigate acute stress effects on response to positive and negative incentives in healthy younger and older adults. The cold pressor task will be used to induce a neurophysiological stress response and repeated testing will allow for assessment of intra-individual stress responses. After the stress manipulation, participants will complete a feedback-based probabilistic learning task during functional magnetic resonance imaging. The goal of the task is to maximize gains and minimize losses by using trial and error to determine which of several novel stimuli in choice pairs are more likely to yield positive feedback (e.g., +$1) and which are more likely to result in negative feedback (e.g., -$1). Neural response to reinforcer-associated stimuli, prediction error, and feedback will be determined. Salivary cortisol levels will be used as a measure of hypothalamic-pituitary-adrenal axis reactivity to stress. In addition, cerebral blood flow will be measured at rest under stress and control conditions to examine brain regions modulated by cold pressor stress in young and old in the absence of a cognitive task. By combining neuroimaging, neuroendocrine and cognitive behavioral approaches, the proposed study will provide substantial insight into the neurophysiological mechanisms of stress effects motivated cognition in aging. PUBLIC HEALTH RELEVANCE: The findings of this study will help us to understand how the common experience of stress can alter motivation and decision making, and how these stress effects may change with age. Determining how stress affects older adults' motivation in decision making is of particular importance due to declines in cognitive function with aging and the rising number of elders faced with complex decisions about healthcare, investments, and interpersonal relationships. The results of this study will provide information about older adults' ability to manage economic decisions and may inform interventions targeted at addressing the specific needs of older adults exposed to stress.

描述（由申请人提供）：压力在日常生活中很常见，似乎会改变学习和决策，涉及潜在的奖励和惩罚。这一发现可能归因于应激诱导的多巴胺系统活性增强。然而，由于年龄对大脑结构和功能的影响，压力对年轻人和老年人的影响可能有所不同。这项研究的长期目标是了解压力如何影响整个生命周期的动机行为的神经机制。这项研究可用于确定老年人管理经济决策的能力，并制定针对老年人压力需求的干预措施。这项研究的总体目标是确定在正常老化过程中，急性应激对学习的影响机制，包括奖励和厌恶反馈。该研究将解决这些具体目标：1）研究急性应激如何影响对积极和消极反馈的反应，2）研究急性应激如何影响涉及积极和消极激励的学习，以及3）通过脑血流量（CBF）的变化确定对急性应激反应的大脑区域。这项研究的中心假设是，压力会对年轻人和老年人负责反馈学习的大脑区域产生不同的影响，但会选择性地增强两个年龄组中奖励结果的显着性。为了实现这些目标，拟议的研究将使用功能性神经成像来研究健康的年轻人和老年人对积极和消极激励的反应的急性应激效应。冷加压任务将用于诱导神经生理应激反应，重复测试将允许评估个体内应激反应。在压力操作之后，参与者将在功能磁共振成像期间完成基于反馈的概率学习任务。该任务的目标是通过使用试错法来确定选择对中的几种新刺激中的哪一种更有可能产生正反馈（例如，+$1）以及更可能导致负反馈的那些（例如，-$1）。将确定对与神经元相关的刺激、预测误差和反馈的神经反应。唾液皮质醇水平将被用作下丘脑-垂体-肾上腺轴对应激反应的量度。此外，将在压力和控制条件下测量静息时的脑血流量，以检查在没有认知任务的情况下年轻人和老年人受冷加压压力调节的脑区域。通过结合神经影像学、神经内分泌学和认知行为学的研究方法，本研究将为衰老过程中应激影响认知的神经生理机制提供实质性的见解。 公共卫生关系：这项研究的结果将帮助我们了解压力的共同经历如何改变动机和决策，以及这些压力影响如何随着年龄的变化而变化。确定压力如何影响老年人的决策动机是特别重要的，因为随着年龄的增长，认知功能下降，越来越多的老年人面临着关于医疗保健，投资和人际关系的复杂决定。这项研究的结果将提供有关老年人管理经济决策的能力的信息，并可能为针对面临压力的老年人的具体需求的干预措施提供信息。