Using Co-Registration of Eye Movements and Electroencephalography to Investigate Ageing Effects on Word Recognition during Natural Reading

阅读是一项重要的生活技能。此外，晚年经常阅读可能有助于建立认知储备，从而使我们对衰老或疾病的影响更具弹性。因此，了解正常衰老对与阅读相关的认知过程的影响是很重要的。尽管如此，研究的重点主要集中在年轻人身上，对我们年龄的变化知之甚少。两种被广泛用于研究阅读的方法是脑电(EEG)和眼睛跟踪。脑电是一种非侵入性的认知神经科学方法，可以直接测量神经对刺激的反应。当与心理语言学理论相结合时，认知过程可以从反应的时间和大小中推断出来，称为事件相关电位(ERPs)。通过比较不同年龄段的事件相关电位，可以推断处理过程是否不同。然而，这种方法在研究阅读时受到限制，因为它不能准确地确定眼睛何时盯着特定的单词，而且眼球运动会导致脑电数据中的伪影。因此，实验通常使用生态效度较低的范式，在固定的时间段内，屏幕中央一次呈现一个单词。这不允许在阅读速度和旁凹视觉中对单词的处理存在个体差异。相反，眼球跟踪确实允许使用自然的阅读范例。这种行为方法被用来暗示注意力集中在哪里以及关注多长时间。然而，与脑电不同的是，它不直接测量神经活动，因此无法在眼睛盯着一个单词时研究潜在的认知过程。

Reading is an important life skill. Additionally, regular reading in later age may help build up cognitive reserve, thus making us more resilient to effects of ageing or disease. It is therefore important to understand normal ageing effects on cognitive processes associated with reading. Despite this, the focus has mainly been on young adults, and little is known about changes as we age.Two methods which have been used extensively to investigate reading are electroencephalography (EEG) and eye-tracking. EEG is a non-invasive cognitive neuroscience method which can directly measure neural responses to stimuli. When combined with psycholinguistic theories, cognitive processes can be inferred from timing and magnitude of responses, known as event-related potentials (ERPs). By comparing ERPs across age groups, it is possible to infer whether processing differs. However, this method is limited when studying reading because it cannot accurately determine when eyes are fixated on certain words, and eye movements cause artefacts in EEG data. Therefore, experiments have typically used paradigms with low ecological validity, where one word is presented at a time in the centre of the screen for a fixed period. This does not allow for individual differences in reading speeds and processing of words in parafoveal vision. Conversely, eye-tracking does allow natural reading paradigms to be used. This behavioural method is used to imply where attention is focused and for how long. However, unlike EEG, it does not directly measure neural activity, and thus cannot investigate underlying cognitive processes whilst the eyes are fixated on a word.