A Compensatory Functional Neuroanatomy of ADHD

描述（由申请人提供）：工作记忆障碍给ADHD患者在学术、社交和职业活动中造成困难。这个应用程序的总体假设是，ADHD患者在执行工作记忆任务时会改变神经系统。这种改变的系统是执行系统受损的结果，执行系统由前扣带（ACC）和前额叶皮层区域（PFC）提供。执行功能受损会削弱招募辅助大脑区域和支持工作记忆的策略的能力。功能成像技术为我们提供了一个了解这些策略的神经基础的窗口。我们的成像数据表明，语音排练策略和大脑区域subserving他们受损多动症。然而，视觉空间策略及其相关的神经网络却完好无损。有限的语音和视觉策略可能会增加错误和加工速度。本研究的主要目的是：1）利用减法技术结合视觉序列加法任务，确定ADHD儿童工作记忆缺陷的神经相关因素; 2）确定工作记忆任务中BOLD信号变化与行为的关系（反应时间，错误类型;课堂评分）;和3）比较ADHD儿童与组合亚型疏忽亚型，以确定与每一个相关的工作记忆神经策略。我们假设，一个一般的模式将出现在ADHD合并型科目使用一个占主导地位的视觉空间的策略来执行工作记忆串行添加任务。在自然环境中ADHD功能障碍的程度预计与视觉空间激活呈正相关，与前额叶皮层激活呈负相关。我们预测ADHD-注意力不集中型在任务执行过程中不会表现出与组合型相同的视觉空间激活水平。相反，他们将在正常对照儿童激活的相同区域中表现出减少的激活。更好地了解ADHD中使用的策略对ADHD儿童如何学习和治疗目标具有潜在的教育意义。

DESCRIPTION (provided by applicant): Impairments in working memory create difficulties for individuals with ADHD in their academic, social, and occupational activities. The overall hypothesis of this application is that individuals with ADHD engage an altered neural system when performing working memory tasks. This altered system arises as a consequence of an impaired executive system, which is subserved by the anterior cingulate (ACC) and prefrontal cortical regions (PFC). Impaired executive functioning weakens the ability to recruit subsidiary brain regions and strategies that support working memory. Functional imaging techniques give us a window into the neural basis of those strategies. Our imaging data suggest that phonological rehearsal strategies and the brain regions subserving them are impaired in ADHD. Visual-spatial strategies and their associated neural networks, are however, intact. Limited access to both phonological and visual strategies may increase errors and processing speed. We propose the following aims to investigate working memory in children with ADHD: 1) Define the neural correlates of working memory deficits in ADHD children using subtraction techniques in conjunction with a visual serial addition task; 2) Identify the relationship between BOLD signal changes generated during a working memory task and behavior (response time, error type; classroom ratings); and 3) Compare ADHD children with the Combined subtype to Inattentive subtype to identify the working memory neural strategies associated with each. We hypothesize that a general pattern will emerge in which ADHD combined type subjects use a predominantly visual-spatial strategy to perform a working memory serial addition task. The degree of ADHD dysfunction in the natural setting is expected to positively relate to visualspatial activation and negatively to prefrontal cortical activation. We predict that the ADHD-inattentive type will not exhibit the same level of visual-spatial activation during task performance as the Combined-type. Instead they will exhibit reduced activation in the same regions activated by the normal control children. A better understanding of strategies used in ADHD has potential educational implications for how children with ADHD learn and targets for treatment.