(28)认知储备-Cognitive Reserve-公开课-关爱惟士
(28)认知储备-Cognitive Reserve

课程视频:http://player.youku.com/embed/XMjY3ODM4MzY5Ng




Difference between pathology and dementia

Dr David Ward

David Ward博士


When we talk about the developments of dementia, there are two distinct events that are worth mentioning. The first is the development of the disease. So in the case of Alzheimer's that's the amyloid plaques and the neurofibrillary tangles, and these can cause some detrimental effects such as atrophy or shrinkage to the brain. Now the other event that occurs, is obviously the onset of dementia, so that's the cognitive impairment, and the deficits in memory and attention that are associated with Alzheimer's disease.

当我们谈论认知症的发展时,有两个不同的事件值得一提。首先是疾病的发展。因此,在阿尔茨海默病的情况下,会出现淀粉样斑块和神经原纤维缠结,并且这些可以引起一些像大脑萎缩或收缩有害的结果。其次发生的其他事件,显然是指认知症的发作,所以这是认知损伤,以及与阿尔茨海默病相关的记忆和注意力的缺陷。


Interestingly we know that there isn't a direct relationship between the level of damage in someone's brain and their cognitive function. For instance, some people can have quite a high load of damage, a large presence of Alzheimer's pathology, yet they're still functioning normally, and they aren't suffering from any of these detrimental memory deficits.

有趣的是,我们知道在某人的大脑的损伤水平和认知功能之间没有直接的联系。例如,一些人可能具有相当高的损伤负荷,大量存在阿尔茨海默氏病理现象,但认知功能仍然正常运行,并且他们没有遭受任何这些有害的记忆缺陷。


Other people can have just a small level of damage to their brain, yet they start showing these deficits on a day-to-day basis, and they have more difficulty with memory function and planning. We aren't exactly sure why some people seem to be more resilient to Alzheimer's, while other people seem to be more susceptible to its effects, but one of the factors that may partially account for some of these individual differences in when dementia symptoms begin to emerge, is cognitive reserve.

其他人的大脑可能只受到小小的伤害,但他们开始在日常生活的基础上显示缺陷,他们在记忆功能和计划方面有更多的困难。我们不能确定为什么有些人似乎对阿尔茨海默氏病更有韧性,而其他人似乎更容易受到其影响,但是其中一个因素可能部分地解释了,当认知症状开始时一些个体差异的出现,这就是认知储备。


Introduction to cognitive reserve

认知储备的介绍


Dr David Ward

What we see is that the level of protection that someone has from the emergence of dementia is related to their cognitive reserve, and cognitive reserve seems to be built from a lifetime of exposure to cognitive stimulation. Simply put, if you live a life that is more cognitively engaged and you're more involved with these complex learning activities, then, on average, you'll have a lower risk for dementia later in life. For example, we might have two individuals, person A, and person B, and they both have exactly the same level of damage within their brain as a result of Alzheimer's disease. However, person A has greater cognitive reserve, and what that means is that they don't display any of these deficits, any of these dementia symptoms, and they're going about their business fairly normally. Person B however, they have less cognitive reserve, and although they only have the same level of damage as person A, what we see is that they might start showing some of these day-to-day difficulties in memory and attention, some of the earlier symptoms of Alzheimer's disease.

我们知道某人痴呆出现的保护水平与他们的认知储备有关,而认知储备似乎是建立在一生的接触认知刺激上。简单地说,如果你生活在一个更具认知参与性的生活环境,并且你更多地参与这些复杂的学习活动,那么一般来说,你患认知症的风险会较低。例如,我们可能有A和B两个人,阿尔茨海默病在他们的大脑内造成的损害完全相同。然而,A具有更大的认知储备,这意味着他们不显示任何这些缺陷、任何认知症状,并且他们正常地进行他们的业务。然而B的认知储备较少,虽然他们只有与A相同程度的伤害,但我们所看到的是他们可能开始在日常记忆和注意力上显示出一些困难,表现出阿尔茨海默病的早期症状。


However, something worth mentioning is that cognitive reserve is a theoretical construct. Now a theoretical construct is something that we believe to exist, because it explains a number of associations, but we can't directly measure it or observe it. In the case of cognitive reserve, it provides a great explanation for why people with more years of education have a lower risk of dementia, but we can't directly measure it. We can't go into someone's brain and look at a specific structure that seems to expand when they're exposed to more years of education. Despite this, we do have a few ideas as to how cognitive reserve does look in the brain, and we can start to differentiate between brains that have high cognitive reserve and low cognitive reserve, based on their structure and function.

但值得一提的是,认知储备是一种理论结构。理论结构是指我们认为存在的某样东西,因为它解释了一些关联,但我们不能直接测量或观察它。认知储备为有更多的受教育年数的人具有较低的痴呆风险这一现象提供了一个很好的解释,但我们不能直接测量它。当人们接触更多的教育时,大脑特定的结构似乎在扩大, 但我们无法进入某人的大脑来看这个结构。尽管如此,我们确实有一些关于如何在大脑中观察认知储备的想法,我们可以基于它们的结构和功能开始区分具有高认知储备和低认知储备的大脑。


What cognitive reserve looks like in the brain

认知储备在大脑看起来怎样?


Dr David Ward

What we think happens, is when a brain is exposed to this prolonged engagement in challenging cognitive stimulation, this induces changes to the structure and the function of the brain, to make it more resilient and more flexible. There are two main components here at work. The first is neural resilience. Neural resilience refers to differences in the efficiency of the neural networks within a brain. Neural flexibility, on the other hand, refers to differences in the ability to recruit additional neural networks to process a task, when the original network is disrupted by pathology. A neural network is a collection of neurons and synapses within the brain that work together to help process a task. So, in one case it might be if you enter a supermarket and you forgot your shopping list, there might be a number of networks involved with trying to remember those items. If there is damage to these networks, or they can't function normally, then that's when you start to have difficulties remembering, and with other cognitive processes.

我们认为当大脑暴露于这种长期参与认知刺激的挑战时,会诱导大脑的结构和功能发生变化,使其更具弹性和更灵活。这里有两个主要组成部分。首先是神经韧性。神经韧性是指脑内神经网络效率的差异。另一方面,神经灵活性是指当原始网络被病理学破坏时,招募额外神经网络以处理任务的能力的差异。神经网络是大脑内的神经元和突触的集合,它们一起工作以帮助处理任务。所以,假如你进入一个超市,你忘了你的购物清单,可能有一些网络涉及尝试记住这些项目。如果这些网络有损坏,或者它们不能正常工作,那么你就会开始在记忆和与其他认知过程上有困难。


Neural resilience and flexibility

神经弹性和灵活性


Dr David Ward

To better understand how these differences in neural resilience and neural flexibility may actually operate, a nice metaphor may be to use a delivery van driving along city streets. In this metaphor, the delivery van represents a neural impulse that's travelling across the brain to help process one of those tasks, such as remembering the items on the shopping list, and the city streets represents the neural networks within your brain, and the pathways. If you have high cognitive reserve, then you have greater neural resilience and greater efficiency within your neural networks. When the delivery van is driving along a street and it wants to make a delivery at the other side of town, if it's driving along a nice high quality street, then it's not going to face any difficulties at all. Even if a bit of damage starts to occur to this road, because of its pre-existing high quality, quite a large amount of damage needs to occur before that delivery van starts to have difficulties in actually making its delivery, and a very high amount of damage needs to occur before it can't make its delivery.

为了更好地了解这些神经弹性和神经灵活性的差异实际上如何运作,一个很好的比喻可能是使用一辆送货车沿着城市街道驾驶。在这个比喻中,送货车代表一个神经冲动,它穿越大脑,帮助处理这些任务之一,例如记住购物清单上的项目,城市街道代表你的大脑和路径中的神经网络。如果你有高认知储备,那么在你的神经网络里你有更大的神经弹性和更大的效率。当沿着一条街道驾驶送货车,并想要在城市的另一边交货的话,如果沿着一个相当的高品质的街道,那么不会遇到任何困难,即使在这条道路上开始发生一点损坏。由于道路预先存在的高质量,只有发生相当大的损坏,然后才会导致运输车实际进行其运输开始有困难,并且只有道路发生非常高的损害量,运输车才无法送货。


However, if you compare that to an individual with low cognitive reserve and low neural resilience, then the delivery van is driving along a road that's already pretty poor quality. There might be a few potholes and it's pretty clear that the council's been neglecting it over the last few years. The delivery van can still make its delivery, but if any further damage occurs to that road, then it's probably going to be un-driveable pretty quickly. Neural resilience refers to the differences in the quality of the pathways, the differences in the quality of the neural networks and their efficiency, whereas neural flexibility refers to the differences in the ability to recruit additional roads to make your delivery if necessary. So let's go back to the delivery van, and what we might see is that the van is driving along, and so much damage has occurred to that road that it can no longer pass and it's making its delivery more difficult. If someone has high neural flexibility, they'll be able to back up the van and they'll be able to think, “Well, if I take a left here, and then I take a right, then I'll still get to my destination, even though I'm not travelling along the road I'm intending to travel along.” We compare that to someone with lower neural flexibility, and what we might see is the van backs up, but because there aren't so many options within the street, the van has no way to get to its destination other than travelling along that damaged road, which it can't do. To sum up, neural resilience refers to the differences in the quality of the roads, whereas neural flexibility refers to the differences in the number of options.

但如果你比喻一个具有低认知储备和低神经韧性的人,那就是送货车沿着已经相当差的道路驾驶。可能有几个坑洼,很明显,在过去几年里,市政委员会一直忽视它。送货车仍然可以送货,但如果那条道路发生任何进一步的损坏,那么送货车可能会很快不能送货。神经韧性指的是道路质量的差异,神经网络质量的差异及其效率,而神经灵活性是指在必要时招募额外道路以完成你的交付任务的能力差异。所以让我们回到送货车,我们可以看到的是,送货车正在沿这条道路行驶,由于这条道路已经发生了如此多的损失,以至于无法再通过,使得送货变得更困难。如果有人有高度的神经灵活性,他们会将运货车后退,他们将能够这样想,“嗯,如果我在这里左转一下,然后我再右转一下,然后我仍然会到达我的目的地,即使我不是沿着我平时的那条路线行驶。“我们比较那些具有较低的神经灵活性的人,我们可能看到的是货车后退了,但因为没有多种道路选择,除了沿着损坏的道路行驶没有别的选择,从而没有办法到达目的地。总之,神经韧性是指道路质量的差异,而神经柔性是指选择数量的差异。


How can you increase your cognitive reserve?

我们能够如何增加认知储备?


Dr David Ward

The question of how can we increase our cognitive reserve is really important. If there were a way to lower your risk of dementia, and many people in the world, or just in Australia, undertook that activity, then we would have a much lower prevalence of dementia. Typically, if an individual wants to increase their cognitive reserve, the best activities are those activities that involve prolonged engagement with cognitively challenging activities, that preferably involve new learning, learning of new knowledge or skills.

我们如何增加认知储备?这个问题是非常重要的。如果有办法降低痴呆的风险,世界上许多人,或只在澳大利亚采取行动的话,那么我们的认知症患病率会低得多。通常,如果个体想要增加他们的认知储备,最好的活动是那些涉及长期参与认知上有挑战性的活动,尤其是涉及新的学习,新的知识或技能的学习。


A great example of an activity that involves prolonged engagement in a cognitively challenging task, is learning a second language. When you learn a second language you're taking in new vocabulary, you're learning how to structure your sentences properly, and it takes quite a long time. It's quite difficult, but it's also achievable, and that's a really key point. There's no point throwing yourself into a task that is so difficult that you can't actually see yourself getting better at it.

对于涉及长期参与挑战性认知任务的活动,学习第二语言是一个很好的例子。当你学习第二种语言,你正在学习新的词汇,你正在学习如何正确地造句,它需要相当长的时间。虽然这是非常困难的,但是它也可以实现的,这是一个真正的关键点。让自己陷入一项艰巨的任务,无法确实看到自己做得越来越好是没有任何意义的。


As a result of this activity, your brain has to change, it has to restructure and reorganise itself, and that's what we think increase in cognitive reserve looks like in a brain. Although it's helpful to give a few examples of certain activities that might be good for increasing cognitive reserve, typically in the research and in the literature, we talk about more broad categories of lifetime exposures. What we find is that people who have more years of education have a lower risk of dementia later in life. It's not just limited to education however, and people who are involved in occupations that involve more complexity, with people or things, have a lower risk of dementia as well. A great example of these occupations are those positions that involve management of people, because that's a difficult and challenging thing to accomplish. An individual's engagement in cognitively stimulating leisure activities also seems to be associated with a reduced risk of dementia. We think that people who read more books or visit museums more regularly have a higher cognitive reserve than those who do these activities less frequently. The take home message, however, if you want to increase your cognitive reserve, is that you need to be challenging yourself with new learning on a regular basis.

作为这个活动的结果,你的大脑必须改变,它必须重建和重组自己,这就是我们认为增加的认知储备看起来像在大脑中。虽然提供一些可能有益于增加认知储备活动的例子是有帮助的,特别是在研究和文献中,我们谈论‘一生暴露’的更广泛的类型。我们发现,受教育年数越多的人将来患痴呆的风险越低。然而它不仅局限于教育,而且从事涉及更复杂人或事的职业的人也具有较低的痴呆风险。这些职业的一个很好的例子是那些涉及人员管理的职位,因为这是一个要完成艰难和具有挑战性事情的职位。个人参与认知刺激的休闲活动也似乎与降低痴呆的风险有关。我们认为,阅读更多书籍或经常访问博物馆的人比没有经常参加这些活动的人具有更高的认知储备。但是,需要带回家的消息是,如果你想增加你的认知储备,你需要定期学习新事物来挑战自己。


Brain reserve vs. cognitive reserve

大脑储备vs认知储备


Dr David Ward

To make things a bit more complicated, you can split this up, these protective effects, into cognitive reserve and brain reserve, and that's quite a useful distinction to make. To understand the differences between cognitive reserve and brain reserve better, we can use a hardware and software metaphor. Brain reserve refers to the hardware, so it's what you have in your brain. It's how big your brain is, it's how many neurons you have, and it's how many synapses you have, among other things. Interestingly, if you have a larger head circumference, that is associated with a reduced risk of dementia. It's quite a crude measure, but what we think happens there is that the more brain you have, the more brain you have to lose, before you start showing some of these clinical deficits associated with Alzheimer's disease. Cognitive reserve, on the other hand, refers to the more software side of things, so that refers to the differences in how you use what you have. As discussed, there are differences in neural efficiency and neural flexibility, and these can lead to a brain that's big that's not very efficient, or it can lead to a brain that's small that's very efficient.

为了使事情有点复杂,你可以把这些保护效应分成认知储备和脑储备,这是一个有用的区别。为了更好地理解认知储备和脑储备之间的差异,我们可以使用硬件和软件隐喻。脑储备是指硬件,所以它是指在你的大脑中有啥。它是指你的大脑有多大,有多少神经元,有多少突触,等等。有趣的是,如果你有一个更大的头围,这是与痴呆的风险降低相关联。这是一个相当粗略的措施,但我们认为如果你有更多的大脑,你必须失去更多的大脑,才能开始显示一些这些临床障碍与阿尔茨海默病相关联。另一方面,认知储备更多是指软件方面的东西,指的是如何使用你所拥有的差异。如前面所讨论的在神经效率和神经灵活性上的差异可以导致大的,不是非常有效率,或者它可以导致小的,非常有效的大脑。


翻译:关爱惟士-未经允许不得转载,违者必追究法律责任

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