Age-related differences in the neural bases of phonological and semantic processes in the context of task-irrelevant information
Age-related differences in the neural bases of phonological and semantic processes in the context of task-irrelevant information
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DOI：
10.3758/s13415-018-00671-2
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发表时间：
2019-08-01
影响因子：
2.9
通讯作者：
Madden, David J.
中科院分区：
文献类型：
--
作者：
Diaz, Michele T.;Johnson, Micah A.;Madden, David J.
随着年龄的增长，我们在语言产生的语音方面遇到了越来越多的困难。然而，语义过程在整个生命周期中基本上是稳定的。这表明支持这些系统的认知和潜在神经架构存在根本差异。此外，这样的语言过程与其他认知过程相互作用，这些认知过程也显示出与年龄相关的衰退，如执行功能和抑制。本研究考察了存在与任务无关的信息时的语音和语义加工，以考察这些材料对语言产生的影响。年长的和年轻的成年人在出现与任务无关的语音或语义相关的单词的情况下，对图片做出语音和语义决定。语义状态下的fMRI激活表明，所有成年人都参与了典型的左半球语言区，而且这种激活与所有成年人的效率呈正相关。相反，语音条件在双侧楔前叶和扣带回引起激活，没有明确的脑-行为关系。同样，在与行为表现无关的几个区域，老年人比年轻人表现出更大的活跃度。我们的结果表明，随着年龄的增长，大脑与行为的关系会下降，对语言特定和领域通用的大脑区域的依赖程度都会增加，这两个区域在语音处理过程中最明显。相反，核心语义系统在整个生命周期中继续参与，即使在存在与任务无关的信息的情况下也是如此。
As we age we have increasing difficulty with phonological aspects of language production. Yet semantic processes are largely stable across the life span. This suggests a fundamental difference in the cognitive and potentially neural architecture supporting these systems. Moreover, language processes such as these interact with other cognitive processes that also show age-related decline, such as executive function and inhibition. The present study examined phonological and semantic processes in the presence of task-irrelevant information to examine the influence of such material on language production. Older and younger adults made phonological and semantic decisions about pictures in the presence of either phonologically or semantically related words, which were unrelated to the task. FMRI activation during the semantic condition showed that all adults engaged typical left-hemisphere language regions, and that this activation was positively correlated with efficiency across all adults. In contrast, the phonological condition elicited activation in bilateral precuneus and cingulate, with no clear brain-behavior relationship. Similarly, older adults exhibited greater activation than younger adults in several regions that were unrelated to behavioral performance. Our results suggest that as we age, brain-behavior relations decline, and there is an increased reliance on both language-specific and domain-general brain regions that are seen most prominently during phonological processing. In contrast, the core semantic system continues to be engaged throughout the life span, even in the presence of task-irrelevant information.