Department of Psychology, University of Utah, University of Illinois at Urbana-Champaign, United States.
Department of Psychology, Program in Neuroscience, and Beckman Institute, University of Illinois at Urbana-Champaign, United States.
Neuropsychologia. 2017 Nov;106:358-370. doi: 10.1016/j.neuropsychologia.2017.10.002. Epub 2017 Oct 4.
Normative aging is associated with deficits in visual acuity and cognitive control that impact the allocation of visual attention, but little is known about how those changes affect information extraction and integration during visual language comprehension in older adulthood. In the current study, we used a visual hemi-field flanker RSVP paradigm with event-related brain potentials to study how older readers process fine-grained aspects of semantic expectancy in parafoveal and foveal vision. Stimuli consisted of high constraint sentences with expected, unexpected but plausible, or anomalous parafoveal target words, as well as low constraint sentences with neutral but expected target words. Older adults showed graded parafoveal N400 effects that were strikingly similar to younger readers, indicating intact parafoveal semantic processing. However, whereas young adults were able to use this parafoveal pre-processing to facilitate subsequent foveal viewing, resulting in a reduced foveal N400 effect, older adults were not able to. Instead, older adults re-processed the semantics of words in foveal vision, resulting in a larger foveal N400 effect relative to the young. Collectively, our findings suggest that although parafoveal semantic processing per se is preserved in aging, there exists an age-related deficit in the ability to rapidly integrate parafoveal and foveal visual semantic representations.
正常衰老与视力和认知控制能力下降有关，这些会影响视觉注意力的分配，但对于这些变化如何影响老年人在视觉语言理解过程中信息的提取和整合，我们知之甚少。在目前的研究中，我们使用了一种带有事件相关脑电位的视觉半视野 Flanker RSVP 范式，来研究老年读者如何在视场下和视场中处理语义预期的细微方面。刺激物由高约束性句子组成，句子包含预期的、意外但合理的或异常的视场下目标词，以及低约束性句子，包含中性但预期的目标词。老年读者表现出分级的视场下 N400 效应，与年轻读者非常相似，表明视场下语义处理完好无损。然而，虽然年轻成年人能够利用这种视场下的预处理来促进后续的视场观看，从而减少视场下 N400 效应，但老年成年人却不能。相反，老年成年人会重新处理视场中单词的语义，导致相对于年轻成年人，视场中 N400 效应更大。总的来说，我们的研究结果表明，尽管衰老本身对视场下的语义处理有保留，但在快速整合视场下和视场中视觉语义表示的能力上存在与年龄相关的缺陷。
