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

描述（由申请人提供）： 目的：这项研究的目的是确定老年人右额叶皮层（右三角部）活动的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，将对老年人和年轻人的皮质实验区（右三角部：R PTr）和对照区（右盖部：R POp）施加1 Hz重复经颅磁刺激（rTMS）。还将应用假rTMS进行比较。1 Hz rTMS已被证明会降低皮质的兴奋性，从而干扰其功能。如果增加的R PTr活动有助于老年人的单词检索，那么与假rTMS相比，1 Hz rTMS应该会干扰他们的单词检索和缓慢的图片命名。然而，如果R PTR活动实际上干扰了老年人的单词检索，正如我们假设的那样，那么降低其兴奋性应该会增强单词检索，并加快图片命名与假rTMS相比。 研究方法：16名右撇子老年人（65-89岁）和16名右撇子年轻人（20-34岁）将在功能性磁共振成像（fMRI）期间进行图片命名，以定义两个右额叶区域的峰值活动区域：在单独的会话中，两组将在来自fMRI的峰值活动位点处接收10分钟的R PTr和R POp的1 Hz rTMS。在每次会话期间，还将进行假1 Hz rTMS。在真实的和假rTMS之后，受试者将立即命名30张图片，并记录图片命名的反应时间。先验分析将进行如下：（1）老年和年轻受试者的重复测量t检验将评估从R PTr的假rTMS到真实的rTMS，图片命名的反应时间是否存在显著变化。我们假设rTMS会加快老年人的反应时间，而不是年轻人。(2)重复测量t检验将评估R PTR与R Pop会话从假手术到真实的rTMS的反应时间变化之间是否存在显著差异。因变量将是R PTr和R POp阶段从假手术到真实的rTMS（真实的减去假手术）的图片命名反应时间的变化。我们假设，老年人的反应时间将加快R PTr相对于R POp。临床相关性：这项工作在两个方面具有临床相关性：首先，如果我们能确定老年人单词检索能力差的原因，那么我们就可以设计一种干预措施来治疗那些表现出单词检索能力差或有这种风险的老年人。这种干预措施不仅可以提高生活质量B加强沟通，将减少健康状况不佳的机会。第二，左半球中风后失语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对中风幸存者失语症治疗的概念化和发展能力。 公共卫生相关性： 在近2200万美国退伍军人中，38.5%超过65岁。随着55岁至64岁的退伍军人增加24.9%，65岁以上的退伍军人人数将在未来十年急剧增加。老年人的词汇提取从50年代末到90年代在独立生活的社区居住的成年人中下降。我们的研究表明，与年轻人相比，老年社区居民的单词检索速度和准确性都受到影响。不好的词汇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，老年人的右额叶活动是否有助于或损害单词查找。最终，这些信息可用于制定干预措施，以解决老年人在沟通不良的风险中发现单词的问题，从而影响数百万退伍军人的生活质量和健康状况。

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.