Department of Bioengineering, School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Neuroimage. 2010 Feb 15;49(4):3436-42. doi: 10.1016/j.neuroimage.2009.11.019. Epub 2009 Nov 14.
Older adults responding to executive control function (ECF) tasks show greater brain activation on functional MRI (fMRI). It is not clear whether greater fMRI activation indicates a strategy to compensate for underlying brain structural abnormalities while maintaining higher performance.
To identify the patterns of fMRI activation in relationship with ECF performance and with brain structural abnormalities.
Cross-sectional analysis.
fMRI activation, accuracy while performing an ECF task (Digit Symbol Substitution Test), and volume of white matter hyperintensities and of total brain atrophy.
Cohort of community-dwelling older adults.
Data were obtained on 25 older adults (20 women, 81 years mean age).
Accuracy (number of correct response/total number of responses) while performing the Digit Symbol Substitution Test.
Greater accuracy was significantly associated with greater peak fMRI activation, from ECF regions, including left middle frontal gyrus and right posterior parietal cortex. Greater WMH was associated with lower activation within accuracy-related regions. The interaction of accuracy by white matter hyperintensity volume was significant within the left posterior parietal region. Specifically, the correlation of white matter hyperintensity volume with fMRI activation varied as a function of accuracy and it was positive for greater accuracy. Associations with brain atrophy were not significant.
Recruitment of additional areas and overall greater brain activation in older adults is associated with higher performance. Posterior parietal activation may be particularly important to maintain higher accuracy in the presence of underlying brain connectivity structural abnormalities.
在执行控制功能（ECF）任务时，反应较慢的老年人在功能磁共振成像（fMRI）中显示出更大的大脑激活。目前尚不清楚更大的 fMRI 激活是否表明存在一种策略，即在保持较高表现的同时补偿潜在的大脑结构异常。
确定与 ECF 表现和大脑结构异常相关的 fMRI 激活模式。
横断面分析。
fMRI 激活、执行 ECF 任务（数字符号替代测试）的准确性以及脑白质高信号体积和总脑萎缩体积。
社区居住的老年人队列。
数据来自 25 名老年人（20 名女性，平均年龄 81 岁）。
更高的准确性与更大的 fMRI 激活峰值显著相关，这些激活区域包括左额中回和右顶后皮质。更大的脑白质高信号与准确性相关区域内的低激活相关。准确性与脑白质高信号体积的相互作用在左顶后区域内显著。具体而言，脑白质高信号体积与 fMRI 激活的相关性随准确性而变化，对于更高的准确性呈正相关。与脑萎缩的关联不显著。
老年人大脑的额外区域招募和整体更大的激活与更高的表现相关。顶后区的激活对于维持更高的准确性可能尤为重要，因为其存在潜在的大脑连通性结构异常。
