Mechanisms of Stochastic Resonance in Human Postural Control

人体姿势控制中的随机共振机制

• 批准号: RGPIN-2014-04666
• 负责人: Vette, Albert
• 金额: $ 2.11万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683157
• 关键词: Mechanisms; Stochastic; Resonance; Human; Postural

The complex task of stabilizing the body in an upright position is critical for performing many daily activities and avoiding falls. In spite of this importance, balance control is still not fully understood. Recently, a phenomenon called stochastic resonance has been used to gain insights into and enhance balance control during standing. It describes a mechanism that uses noise to improve the detection and transmission of weak signals in various systems. Stochastic resonance is based on the concept that the flow of information through a system can be maximized by an optimal level of noise. While the effect of such noise on the sensory system has been documented, it is unclear to what degree its benefits extend to processes within the brain. Accordingly, it is possible that improved balance control in the presence of sensory noise is a result not only of better signal detection, but also of increased activity in higher brain areas.**Building upon my experience in balance control, the long-term objective of this research program is to understand the central and peripheral mechanisms that are responsible for postural improvements via sensory noise. To reach this goal, the first objective is to deliver mechanistic evidence for the effect of sensory noise on speed of processing, a key factor of balance control. We will use a simple reaction time task to determine the relationship between noise-evoked changes in reaction times and various states of brain activity. The second objective is to identify physiological and behavioural factors of reactive balance control that are changed by sensory noise. In contrast to quiet upright standing, a perturbed standing paradigm will allow us to isolate noise-enhanced activity at both the sensory and motor stages of central processing. In addition, insights from reactive balance control will provide a good scientific basis for developing interventions that reduce balance impairments via sensory noise. In both lines of research, noise-evoked changes will be captured by physiological and behavioural measures (brain and muscle activity, arousal, etc.).**The effect of sensory noise on quiet upright standing has been documented. However, our understanding of its impact on functionally more relevant tasks such as reactive balance control is limited. At the same time, it is unclear if noise-induced changes are linked to increased activity of higher brain areas. To address these shortfalls, we will characterize the influence of sensory noise on speed of processing and other factors of reactive balance control. We expect to make important contributions in the area of human systems and functions. First, we will determine whether reaction times can be reduced via sensory noise and how a potential effect depends on internal noise within the brain. Second, changes to the activity in certain brain areas will indicate that sensory noise does not only enhance sensory detection, but also central processing associated with the execution of a balance response. Finally, we will characterize effects of sensory noise on reactive postural control in dependence of the noise modality and its involvement in the recovery task. While the expected contributions are fundamental in nature, they will also have important implications for applied fields such as human health and performance. For example, the intended comparison between young and elderly individuals will serve as an ideal stepping stone for mechanistically informed studies that use sensory noise to reduce fall risk in elderly Canadians. Highly qualified personnel will be trained in a multidisciplinary environment to build capacity for future challenges of our health care system.

将身体稳定在直立位置的复杂任务对于执行许多日常活动和避免福尔斯至关重要。尽管如此重要，平衡控制仍然没有完全理解。最近，一种被称为随机共振的现象已被用于深入了解和增强站立过程中的平衡控制。它描述了一种利用噪声来改善各种系统中弱信号的检测和传输的机制。随机共振是基于这样的概念，即通过系统的信息流可以通过最佳的噪声水平来最大化。虽然这种噪音对感觉系统的影响已经被记录在案，但还不清楚它的好处在多大程度上扩展到大脑内部的过程。因此，在感觉噪声存在的情况下，平衡控制的改善可能不仅是更好的信号检测的结果，而且是大脑高级区域活动增加的结果。根据我在平衡控制方面的经验，本研究计划的长期目标是了解通过感觉噪声改善姿势的中枢和外周机制。为了实现这一目标，第一个目标是提供机械证据的感官噪音的处理速度的影响，平衡控制的一个关键因素。我们将使用一个简单的反应时间任务来确定噪声诱发的反应时间变化与大脑活动的各种状态之间的关系。第二个目标是确定生理和行为因素的反应性平衡控制的感官噪音改变。与安静的直立站立相反，扰动站立范式将使我们能够在中枢处理的感觉和运动阶段隔离噪声增强的活动。此外，来自反应性平衡控制的见解将为开发通过感官噪音减少平衡障碍的干预措施提供良好的科学基础。在这两条研究线中，噪声引起的变化将通过生理和行为测量（大脑和肌肉活动，唤醒等）来捕获。感官噪声对安静直立站立的影响已有文献记载。然而，我们对它对功能上更相关的任务（如无功平衡控制）的影响的理解是有限的。与此同时，目前还不清楚噪音引起的变化是否与大脑高级区域的活动增加有关。为了解决这些不足，我们将描述感官噪声对处理速度和反应平衡控制的其他因素的影响。我们期望在人类系统和功能领域作出重要贡献。首先，我们将确定反应时间是否可以通过感官噪音减少，以及潜在的影响如何取决于大脑内部的噪音。第二，某些大脑区域的活动变化表明，感官噪音不仅能增强感官检测，还能增强与平衡反应执行相关的中央处理。最后，我们将描述感官噪声对反应性姿势控制的影响，依赖于噪声模态及其在恢复任务中的参与。虽然预期的贡献是根本性的，但它们也将对人类健康和绩效等应用领域产生重要影响。例如，年轻人和老年人之间的预期比较将作为一个理想的垫脚石，为机械知情的研究，使用感官噪音，以减少老年加拿大人的跌倒风险。将在多学科环境中培训高素质的人员，以建立能力，应对我国保健系统未来的挑战。