Age differences in deactivation: A link to cognitive control?
Age differences in deactivation: A link to cognitive control?
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DOI：
10.1162/jocn.2007.19.6.1021
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发表时间：
2007-06-01
影响因子：
3.2
通讯作者：
Reuter-Lorenz, Patricia A.
中科院分区：
文献类型：
--
作者：
Persson, Jonas;Lustig, Cindy;Reuter-Lorenz, Patricia A.
功能成像研究显示，相对于名义上更被动的基线（任务<基线），实验任务会使区域网络失活，这可能反映了静息状态或“默认模式”期间参与的过程。“当注意力和资源从默认模式流程转移到任务流程时，可能会导致停用。衰老与失活模式的改变有关，失活模式可能与资源减少、资源分配困难或两者兼而有之有关。这些可能性预测，更大的任务需求，这增加了年轻人的失活水平，应该加剧与年龄有关的资源分配远离默认模式的下降。本研究调查了年轻人和老年人在认知控制需求不同的任务中失活的幅度和时间特性。两个版本的动词生成任务，在竞争的选择不同的需求进行了比较，字阅读和固定基线条件。与我们的假设一致，随着需求的增加，发现了更大的失活。年轻人和老年人在最小选择条件下表现出相同的失活。相比之下，年龄差异的大小和时间过程中的失活增加的选择需求：与年轻的成年人相比，老年人的失活反应表现出较低的敏感性需求。需求相关的变化与性能变化的失活幅度相关，表明个体和群体差异失活功能的意义。
The network of regions shown by functional imaging studies to be deactivated by experimental tasks relative to nominally more passive baselines (task < baseline) may reflect processes engaged during the resting state or "default mode." Deactivation may result when attention and resources are diverted from default-mode processes toward task processes. Aging is associated with altered patterns of deactivation which may be related to declining resources, difficulties with resource allocation, or both. These possibilities predict that greater task demand, which increases deactivation levels in younger adults, should exacerbate age-related declines in allocating resources away from the default mode. The present study investigated the magnitude and temporal properties of deactivations in young and older adults during tasks that varied in their demand for cognitive control. Two versions of a verb generation task that varied in their demand for selection among competing alternatives were compared to word reading and a fixation baseline condition. Consistent with our hypothesis, greater deactivations were found with increasing demand. Young and older adults showed equivalent deactivations in the minimal selection condition. By contrast, age differences in both the magnitude and time course of deactivation increased with selection demand: Compared to young adults', older adults' deactivation response showed less sensitivity to demand. Demand-related changes in deactivation magnitude correlated with performance changes, suggesting that individual and group differences in deactivation have functional significance.