A Biological Framework of Reduced Physical and Social Activity across the Lifespan

几十年来，我们已经知道，参加体育和社交活动对健康有重大好处，包括预防晚年健康不良和改善生病时的症状。尽管有这些好处，许多人并不经常锻炼，而且与社会脱节。随着人们年龄的增长，这种不活动的情况会增加，导致世界各地的医疗系统付出巨大的代价，个人也会付出巨大的个人代价。为什么人们不更活跃呢？阻碍积极生活的一个关键因素是动力。更有动力的人更活跃。即使在其他方面，健康的人也会受到高度动机问题的困扰，比如社交冷漠(人们喜欢社交，但只是没有参与其中的意愿)或疲劳(人们在小范围的努力后感到疲惫)。此外，这些动机障碍随着年龄的增长而增加。然而，我们对人们动机不同的原因知之甚少。是否存在一种社会冷漠和疲惫的生理特征？这项拟议的研究的主要目的是找出大脑中某些系统工作方式的差异与人们社交冷漠或疲惫程度的差异，并研究随着年龄的增长，大脑的变化如何导致动力减弱。为了做到这一点，我将介绍基础神经科学的最新进展，这些进展为我们提供了对大脑如何激励行为的丰富理解。在这项研究中，有人提出，动力减弱可能是由于对行动的努力程度的高度敏感所致。更有动力的人会发现同样的行为不那么费力。在这里，我建议研究努力敏感度的不同方面如何与健康人随着年龄的增长而出现的疲劳和社交冷漠有关。为了做到这一点，我将在健康的人类志愿者身上进行研究，使用多种技术，包括大脑成像、大脑刺激和手机游戏，并使用精确的计算方法量化努力敏感度。将所有这些方法结合起来，我将能够回答有关大脑系统的具体问题，这些系统在社交场合和筋疲力尽时激发行为。通过比较年轻人和老年人努力敏感度背后的大脑系统，我将试图理解，随着人们年龄的增长，大脑中的哪些变化可能会导致更高水平的社交冷漠和疲劳。总而言之，这项拟议的研究将研究的关键问题是：1)社交冷漠和疲劳是否可以被描述为健康人对不同方面的努力的敏感度增加？2)社交冷漠和疲劳是否因为努力敏感度的提高而在一生中增加？3)大脑中的哪些系统构成了努力敏感度的不同方面，它们是否与社交冷漠和疲劳有关？4)老年人大脑系统的变化是否与努力敏感度的增加、社交冷漠和疲劳有关？5)在一个独特的样本中，将大脑深层刺激器植入特定的大脑区域，刺激这些脑区是否提供了这些区域与努力敏感度相关的证据？这项工作将在牛津大学实验心理学系进行。首席研究员(博士Apps)将与一名博士后研究员、纳菲尔德外科科学系的外科顾问医生、惠康综合神经科学信托中心和一家移动大脑培训公司合作。

For decades, we have known that being physically and socially active can have major health benefits, including the prevention of later life ill-health and the improvement of symptoms when sick. Despite these benefits, many people do not engage in regular exercise and are socially dis-engaged. Such inactivity increases as people get older, leading to significant costs to health systems across the world, as well as major personal costs to the individual.Why aren't people more active? A crucial factor that prevents an active life is motivation. People who are more motivated are more active. Even otherwise healthy people can suffer from high levels of motivation problems such as social apathy (people enjoy social interactions but simply don't have the will to engage in them) or fatigue (people who feeling exhausted after small levels of exertion). Moreover these motivational impairments increase as people get older. Yet, we understand very little about why people vary in motivation. Is there a biology of social apathy and fatigue? The overarching aim of the proposed research is to identify how differences in how certain systems in the brain work, relates to differences in how socially apathetic or fatigued people are, and to examine how changes in the brain lead to reduced motivation as we get older. To do this I will extend recent advancements in basic neuroscience that has provided a rich understanding of how the brain motivates behaviour. Within this research it has been suggested that reduced motivation might be due to a heightened sensitivity to how effortful actions are. People who are more motivated find the same actions less effortful. Here, I propose to examine how different aspects of effort sensitivity may be linked to fatigue and social apathy in healthy people as they get older. To do this, I will perform studies in healthy human volunteers using a number of techniques including brain imaging, brain stimulation and a mobile phone game, with effort sensitivity quantified using precise computational approaches. Using all of these approaches together I will be able to answer specific questions about the systems in the brain that motivate behaviour in social situations and when getting exhausted. By comparing the brain systems underlying effort sensitivity in young and older people, I will try and understand what changes in the brain may lead to higher levels of social apathy and fatigue as people get older. In summary, the key questions that the proposed research would examine are:1) Can social apathy and fatigue be characterised as increased sensitivity to different aspects of effort in healthy people? 2) Do social apathy and fatigue increase across the lifespan because of heightened effort sensitivity? 3) What systems in the brain underlie different aspects of effort sensitivity and are they linked to social apathy and fatigue? 4) Are changes in these brain systems in older adults linked to increased effort sensitivity, social apathy and fatigue? 5) Can stimulating these brain areas in a unique sample of individuals with deep brain stimulators implanted into specific brain areas provide evidence of these regions being causally involved in effort sensitivity? This work will be carried out in the Department of Experimental Psychology, at the University of Oxford. The principal investigator (Dr. Apps) will work in collaboration with a postdoctoral researcher, consultant surgeons in the Nuffield Department of Surgical Science, the Wellcome trust Centre for integrated neuroscience and a mobile brain training company.