Right Frontal Activity in Older Adults: Does It Help or Hurt Word Retrieval?

描述(由申请人提供)： 目的：本研究的目的是确定老年人右侧额叶皮质(右侧三角部)的活动增加是否有助于或阻碍单词提取。研究计划：为了实现这一目标，将在老年人和年轻人的实验区(右侧三角部：R PTR)和控制区(右侧盖部：R POP)应用1赫兹重复经颅磁刺激(RTMS)。假rtms也将用于比较目的。1 HzrTMS可降低大脑皮质的兴奋性，从而干扰其功能。如果RPTR活动的增加有助于老年人的单词提取，那么与假的rTMS相比，1赫兹的rTMS应该会干扰他们的单词提取和缓慢的图片命名。然而，如果像我们假设的那样，R PTR活动实际上干扰了老年人的单词提取，那么与Sham rTMS相比，降低其兴奋性应该会增强单词提取并加快图片命名。方法：16名右撇子老年人(65~89岁)和16名右利手年轻人(20~34岁)在功能磁共振成像(FMRI)中进行图像命名，以确定右额叶两个区域的峰值活动区：RPTR和RPOP。在不同的疗程中，两组都将在来自fMRI的峰值活动部位接受10分钟的1赫兹rTMS的R PTR和R POP。在每个会话期间，还将进行假1赫兹rTMS。在真实和虚假的RTMS后，受试者将立即说出30张图片，并记录图片命名的反应时。将进行如下先验分析：(1)对年长和年轻的被试进行重复测量t检验，以评估图片命名的反应时是否发生显著变化，从假名到RPTR的真实rTMS。我们假设rTMS将加快老年人的反应时间，但不会加快年轻人的反应时间。(2)重复测量t检验将评估R PTR与R Pop会话的反应时从假rTMS到真实rTMS之间是否存在显著差异。因变量将是R PTR和R POP会话的图片命名反应时从虚假到真实rTMS(真实减去虚假)的变化。我们假设，与R POP相比，老年人R PTR的反应时间会更快。临床相关性：这项工作在两个方面具有临床意义：首先，如果我们能确定老年人单词提取能力差的原因，那么我们就可以针对表现出单词提取能力差或有此风险的老年人设计干预措施。这种干预不仅将通过加强沟通来提高生活质量，还将减少不良健康结果的机会。其次，左半球中风后出现失语症的患者通常是老年人。了解老年人大脑的一般功能将增强我们概念化和开发中风幸存者失语症治疗方法的能力。 公共卫生相关性： 在近2200万美国退伍军人中，38.5%的人年龄在65岁以上。随着年龄在55岁至之间的退伍军人人数增加24.9%，65岁以上退伍军人的数量在未来十年将大幅增加。在独立生活、社区居住的老年人中，从50年代末的S到90年代的S，老年人的词汇提取能力有所下降。我们的研究表明，与年轻人相比，居住在社区的老年人的单词检索速度和准确性都会受到影响。糟糕的单词提取会影响交流能力。沟通效率降低会影响生活质量，并使老年人面临诊断不准确和健康状况不佳的风险。我们的研究将确定，与年轻人相比，老年人更多的右额叶活动是有助于还是不利于单词查找。最终，这些信息可以用于制定干预措施，帮助面临沟通不良风险的老年人寻找糟糕的单词，影响数百万退伍军人的生活质量和健康结果。

DESCRIPTION (provided by applicant): Objectives: The objective of the proposed study is to determine whether increased activity in right frontal cortex (right pars triangularis) of older persons helps or hinders word retrieval. Research Plan: To accomplish this goal, 1 Hz repetitive transcranial magnetic stimulation (rTMS) will be applied to the experimental area of cortex (right pars triangularis: R PTr) and a control area (right pars opercularis: R POp) in older and younger adults. Sham rTMS also will be applied for purposes of comparison. 1 Hz rTMS has been shown to reduce the excitability of cortex, which interferes with its functions. If increased R PTr activity helps word retrieval for older adults, then 1 Hz rTMS should interfere with their word retrieval and slow picture naming compared to sham rTMS. However, if R PTr activity actually interferes with word retrieval for older persons, as we hypothesize, then lowering its excitability should enhance word retrieval and speed up picture naming compared to sham rTMS. Methods: Sixteen right-handed older adults (65-89 years of age) and 16 right-handed younger adults (20-34 years of age) will perform picture naming during functional magnetic resonance imaging (fMRI) to define areas of peak activity in two right frontal areas: R PTr and R POp. In separate sessions, both groups will receive 10 minutes of 1 Hz rTMS of R PTr and R POp at the locus of peak activity from fMRI. During each session, sham 1 Hz rTMS also will be done. Immediately after both real and sham rTMS, subjects will name 30 pictures, and reaction times for picture naming will be recorded. A priori analyses will be conducted as follows: (1) A repeated-measures t test for both older and younger subjects will assess if there is a significant change in reaction times for picture naming from sham to real rTMS of R PTr. We hypothesize that rTMS will speed up reaction times for older but not younger adults. (2) A repeated-measures t test will assess if there is a significant difference between reaction-time changes from sham to real rTMS for R PTr vs R Pop sessions. Dependent variables will be the change in picture-naming reaction times from sham to real rTMS (real minus sham) for the R PTr and R POp sessions. We hypothesize that reaction times in older adults will speed up for R PTr relative to R POp. Clinical Relevance: This work is clinically relevant in two ways: First, if we can determine the cause of poor word retrieval in older adults, then we can devise an intervention for it in older adults who demonstrate poor word retrieval or who are at risk for it. Such an intervention not only would increase quality of life b enhancing communication, it would reduce the chance of poor health outcomes. Second, patients who have aphasia after left-hemisphere stroke are usually older persons. Knowing how the older brain functions in general will enhance our ability to conceptualize and develop aphasia treatments in stroke survivors. PUBLIC HEALTH RELEVANCE: Of nearly 22 million US veterans, 38.5% are over 65. With an additional 24.9% of veterans between the ages of 55 and 64, the number of veterans over age 65 will increase dramatically in the next decade. Word retrieval in older adults declines from the late 50's through the 90's in independently living, community dwelling adults. Our research indicates that both speed and accuracy of word retrieval are affected in older, community-dwelling adults compared to younger adults. Poor word retrieval affects the ability to communicate. Reduced communication effectiveness can impact quality of life and put older adults at risk for inaccurate diagnosis and poor health outcomes. Our study will determine whether greater right frontal activity in older compared to younger adults helps or hurts word finding. Eventually, this information can be used to develop interventions for poor word finding in older adults at risk for poor communication, impacting quality of life and health outcomes for millions of veterans.