Brain networks that produce word finding difficulty for person's name in old people

人们常说，随着年龄的增长，词汇量会增加，但随着年龄的增长，单词的检索，特别是专有名词，如人名，变得越来越困难。事实上，我们过去对单词检索（语言流畅性任务）的研究表明，老年人的检索性能大约是年轻学生的75%，用于表示动画的单词（例如，哺乳动物、鱼类等）或无生命的（车辆、工具等），在这个项目中，我们做了一个PET激活研究，在语言流畅性任务中，大脑区域被激活，用于语义类别，如动画，无生命和名人的专有名称，以及语音类别（检索以预先指定的音节开头的单词）。我们发现，在年轻的正常受试者中，对动物、非动物和语音线索的言语流畅性激活了包括左颞回下后区（BA 20，37）到颞叶的区域， ...更多信息 左侧额下回（BA44，45）。而左颞回被解释为处理单词语义，左额回被解释为在选择一个合适的词的语义和语音信息的基础上发挥作用。在专有名称提取中，更多的喙区被激活，即，左侧颞叶皮层前部（BA22，38），以及包括额极和内侧额叶皮层（BA10）的区域，前者与词汇选择的深层语义加工有关，后者与词汇选择的控制性加工有关（无生命和专有名词）和语音线索在老年人中，发现几乎相同的区域被激活，但它们的体积往往较小。最近，一些研究人员报告说，在像阅读单词这样的语言任务中，老年人和年轻人的激活区域是不同的，反映了两组人对单词或句子的不同处理。然而，脑萎缩随着年龄的增长而增长，并且萎缩对语言和认知的影响尚未阐明。我们使用一种名为VBM（基于体素的形态测量）的软件，基于77名年轻人和23名老年人的MRI大脑图像，研究了与年龄相关的大脑萎缩。结果发现，正常老年人并没有表现出一致的萎缩，无论大脑区域，而是他们表现出限制性萎缩的区域周围的Syrvian裂，额下至顶叶下区，前内侧额叶区的两个半球，和上级小脑。结果发现，左下后颞回是唯一的区域，不与年龄相关的萎缩重叠，这表明，在老年人缺乏语言流畅性是由于至少部分脑萎缩。少

It is often said that while aging increases vocabulary, retrieval of words, especially proper names such as person's names, becomes difficult with increasing age. Indeed, our past research on word retrieval (verbal fluency task) revealed that the retrieval performance of elderly people was approximately 75 % of younger students for words representing animate (e.g., mammals, fishes, etc.) or inanimate (vehicles, tools, etc.), and only 55 % for proper names (names of politicians, actresses, etc).In this project we did a PET activation study in which brain regions activated during verbal fluency tasks for semantic categories like animates, inanimate and proper names of famous persons, as well as phonological categories (retrieving words beginning with a pre-specified syllable) were explored. We found that in young normal subjects verbal fluency for animates, inanimate and phonological cues activated areas including inferoposterior region of the left temporal gyrus (BA 20,37) to a temporop … More arietal junction, and the left inferior frontal gyrus (BA44,45). Whereas the left temporal gyrus was interpreted to process word semantics, the left frontal gyrus was interpreted to play a role in selecting an appropriate word based on semantic and phonological information. In proper name retrieval, more rostal areas were activated, i.e., the anterior region of the left temporal cortex (BA22,38), and a region including the frontal pole and medial frontal cortex (BA10), the former associating deep semantic processing and the latter more controlled processing of word selection.We also observed activated areas during verbal fluency for semantic categories (inanimate and proper names) and phonological cues in aged people, and found almost the same areas are activated, but their volumes tend to be smaller.Recently, some researchers report that activated areas during language tasks like reading aloud words are different in elderly and young subjects, reflecting differential word or sentence processing in the two groups. However, atrophy of the brain grows with increasing age, and influence of atrophy on language and cognition has not been elucidated. We examined age-related brain shrinkage using a software called VBM(Voxel Based Morphometry) based on MRI brain images of 77 young and 23 old people. It was found that the normal elderly did not show a uniform atrophy regardless of the brain region, rather they showed restricted atrophy in a region surrounding the Syrvian fissure, inferior frontal to inferior parietal region, anteromedial frontal area of both hemispheres, and superior cerebellum. It was found that the left inferoposterior temporal gyrus is an only region that does not overlap with the age-related shrinkage, suggesting that deficient verbal fluency in the elderly is attributable at least in part to brain atrophy. Less