Spread of activation and deactivation in the brain: does age matter?
Spread of activation and deactivation in the brain: does age matter?
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DOI：
10.3389/fnagi.2014.00288
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发表时间：
2014
影响因子：
4.8
通讯作者：
Fabiani M
中科院分区：
文献类型：
--
作者：
Gordon BA;Tse CY;Gratton G;Fabiani M
衰老功能MRI的横断面结果有时难以解释，因为激活和失活的标准测量可能会混淆信号幅度和传播的变化，然而，这些变化可能受到各种解剖和生理因素的年龄相关变化的不同影响。为了理清这两种类型的测量方法，我们提出了一种新的方法，在14名年轻人和28名老年人的Sternberg任务激活（任务阳性）和失活（任务阴性）区域中获得BOLD信号的峰值振幅和传播的独立估计。峰值测量表明，与年轻人相比，老年人的任务积极网络激活增加，但任务消极网络的失活水平相似。对信号传播的测量显示，老年人在任务积极区激活的传播增加，但在任务消极区失活的传播明显减少。这些影响在每个网络的各个区域都是一致的。此外，在老年人中，峰点的解剖定位有更大的可变性，导致交叉受试者重叠减少。这些结果揭示的因素可能会混淆对衰老研究的解释。此外，传播测量可能与局部连通性现象有关，对于分析与年龄相关的失活模式特别有用，可以补充标准峰值和兴趣区域分析获得的结果。
Cross-sectional aging functional MRI results are sometimes difficult to interpret, as standard measures of activation and deactivation may confound variations in signal amplitude and spread, which however, may be differentially affected by age-related changes in various anatomical and physiological factors. To disentangle these two types of measures, here we propose a novel method to obtain independent estimates of the peak amplitude and spread of the BOLD signal in areas activated (task-positive) and deactivated (task-negative) by a Sternberg task, in 14 younger and 28 older adults. The peak measures indicated that, compared to younger adults, older adults had increased activation of the task-positive network, but similar levels of deactivation in the task-negative network. Measures of signal spread revealed that older adults had an increased spread of activation in task-positive areas, but a starkly reduced spread of deactivation in task-negative areas. These effects were consistent across regions within each network. Further, there was greater variability in the anatomical localization of peak points in older adults, leading to reduced cross-subject overlap. These results reveal factors that may confound the interpretation of studies of aging. Additionally, spread measures may be linked to local connectivity phenomena and could be particularly useful to analyze age-related deactivation patterns, complementing the results obtained with standard peak and region of interest analyses.
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影响因子：
64.8
作者：
通讯作者：
--
DOI：
10.1073/pnas.0504136102
发表时间：
2005-07-05
影响因子：
11.1
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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DOI：
10.1098/rstb.2005.1634
发表时间：
2005-05-29
影响因子：
6.3
作者：
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通讯作者：
Smith, SM