Pioneering a New Method for Investigating the Neural Correlates of Ageing Effects during Natural Reading

开创了一种研究自然阅读过程中衰老效应的神经相关性的新方法

• 批准号: ES/R008957/1
• 负责人: Kevin Paterson
• 金额: $ 25.78万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ES%2FR008957%2F1
• 关键词: Pioneering; New; Method; Investigating; Neural

Reading is vital for people to function effectively in modern societies. Furthermore, good reading abilities are important for social inclusion and often essential for individuals to work productively, access educational opportunities and acquire new skills. However, numerous studies show that, compared to young adults (aged 18-30 years), older adults (aged 65+ years) experience considerable difficulty reading even when their visual and mental abilities appear normal. Surprisingly little is known about the underlying cause of this age-related reading difficulty or how it might be combated. However, this issue is likely to be increasingly socially important as the proportion of older people in society increase due to population ageing, as well as the likelihood that they will have extended working lives, often in jobs requiring good reading abilities. Scientific investigations of ageing effects on reading are therefore very important.When we read, our eyes move in a series of high-velocity jumps (saccades) separated by brief pauses (fixations) lasting about a quarter of a second. Readers visually and linguistically process a small portion of text during each fixation, before making a saccade to inspect a new portion. Quantitative measures of these eye movements have been the preferred way to study natural reading, and led to the development of detailed theoretical models of the mental processes that govern this behaviour, including how these might change with age. However, a major limitation of this approach is that eye movements are not directly informative about underlying brain processes, although such knowledge is essential if we are to more fully understand the fundamental mechanisms responsible for ageing effects on reading behaviour.Our project addresses this issue by pioneering a new method that permits the examination of brain processes in real-time during natural reading. This is achieved by simultaneously recording eye movements using a high-precision eye-tracker and electroencephalographic (EEG) measures of brain activity from electrodes placed on the scalp. We then synchronise these signals so that the EEG record is time-locked to individual fixations on specific words in sentences, thereby allowing us to quantify patterns of brain activity that take place as these words are processed visually. Once averaged (over trials in an experiment), the resulting EEG recording (the fixation-related brain potential, or FRP) exhibits a stereotypical waveform with components (peaks and troughs) that are selectively sensitive to factors that influence a word's recognition.The co-registration method is difficult to implement. Our first objective, therefore, is to demonstrate the viability of using this method with older adult participants. We propose then to conduct three experiments to establish the utility of this new method for revealing age differences in word recognition during natural reading. To do this, we will assess ageing effects on two key factors that affect word recognition during reading. The first is the frequency of a word's written usage (and so its familiarity to readers), and the second is the predictability of a word from its prior sentence context. Theoretical accounts of ageing effects predict larger effects of both word frequency and word predictability for older than young adults, due to slower lexical processing and greater reliance on context in older age. It will be important, therefore, to establish if our new method can detect age differences in the influence of these factors on brain processes during reading. There is a significant degree of risk to this project. But if we are successful, the approach we are pioneering is likely to produce a paradigm shift in psychological research on ageing effects on visual cognition (including reading) by providing the tools to develop new theories and obtain new evidence about brain processes that underlie socially-important everyday functions.

阅读对于人们在现代社会中有效地发挥作用至关重要。此外，良好的阅读能力对社会包容很重要，而且往往是个人富有成效地工作、获得教育机会和获得新技能的必要条件。然而，许多研究表明，与年轻人（18-30岁）相比，老年人（65岁以上）即使在视觉和心理能力正常的情况下也会经历相当大的阅读困难。令人惊讶的是，人们对这种与年龄有关的阅读困难的根本原因以及如何克服这种困难知之甚少。然而，随着人口老龄化导致老年人在社会中所占比例增加，以及老年人的工作年限可能延长，而且往往是在需要良好阅读能力的工作中，这一问题可能越来越具有社会重要性。因此，对年龄增长对阅读影响的科学研究非常重要。当我们阅读时，我们的眼睛以一系列高速跳跃（扫视）的方式移动，中间有持续约四分之一秒的短暂停顿（注视）。在每次注视过程中，读者在视觉上和语言上处理一小部分文本，然后进行扫视以检查新的部分。对这些眼球运动的定量测量一直是研究自然阅读的首选方法，并导致了控制这种行为的心理过程的详细理论模型的发展，包括这些过程如何随着年龄的变化。然而，这种方法的一个主要局限是，眼球运动并不能直接提供有关潜在大脑过程的信息，尽管如果我们要更全面地了解衰老对阅读行为的影响的基本机制，这些知识是必不可少的。我们的项目通过开创一种新方法来解决这个问题，该方法允许在自然阅读过程中实时检查大脑过程。这是通过使用高精度眼动仪同时记录眼球运动和通过放置在头皮上的电极测量大脑活动的脑电图（EEG）来实现的。然后，我们同步这些信号，使EEG记录被时间锁定到句子中特定单词的个体注视，从而使我们能够量化这些单词在视觉上处理时发生的大脑活动模式。一旦平均（在实验中的试验），所产生的EEG记录（固定相关脑电位，或FRP）显示出一个刻板的波形，其分量（峰和谷）对影响单词识别的因素有选择性地敏感。因此，我们的第一个目标是证明使用这种方法与老年人参与者的可行性。然后，我们建议进行三个实验，以建立这种新的方法，揭示自然阅读过程中的单词识别的年龄差异的效用。为此，我们将评估年龄对影响阅读过程中单词识别的两个关键因素的影响。第一个是一个词的书面使用频率（因此它对读者的熟悉程度），第二个是一个词从其先前的句子上下文的可预测性。老龄化效应的理论帐户预测更大的影响，词频和词的可预测性，老年人比年轻人，由于词汇处理速度较慢，更依赖于在老年的背景。因此，重要的是要确定我们的新方法是否可以检测这些因素对阅读过程中大脑过程影响的年龄差异。这个项目有很大的风险。但如果我们成功了，我们所开创的方法很可能会在关于衰老对视觉认知（包括阅读）影响的心理学研究中产生范式转变，方法是提供工具来发展新理论，并获得有关大脑过程的新证据，这些大脑过程是社会重要的日常功能的基础。