The functional anatomy of divided attention in amnestic mild cognitive impairment
The functional anatomy of divided attention in amnestic mild cognitive impairment
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DOI：
10.1093/brain/awh413
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发表时间：
2005-06-01
期刊：
影响因子：
14.5
通讯作者：
Shergill, SS
中科院分区：
文献类型：
--
作者：
Dannhauser, TM;Walker, Z;Shergill, SS
最近的神经影像学研究表明，认知正常的受试者患阿尔茨海默病的风险增加，大脑功能发生变化。遗忘型轻度认知障碍（AMCI）具有发展为阿尔茨海默病的高风险。在AMCI中，使用功能性MRI（fMRI）在记忆任务期间已经证明了皮质激活的改变。记忆和注意是密切相关的认知功能。目前尚不清楚AMCI的记忆障碍是否与需要分散注意力的任务可能揭示的注意力缺陷有关。10名AMCI老年人（平均年龄72岁，范围57-81岁）与健康匹配的对照组进行了比较，使用功能磁共振成像的分散注意力和被动感觉处理任务。在分散注意力的任务中，两组人都激活了左半球前额叶和纹外视皮层的相似区域。然而，与年龄匹配的对照组相比，AMCI组的前额叶激活减弱。在被动感觉加工任务上，AMCI组和对照组之间没有差异。我们的结论是，有变化的功能网络subserving分散注意力的AMCI患者反映在前额叶皮层激活的衰减。这些发现对评估AMCI的认知能力以及监测AMCI未来治疗的效果具有重要意义。
Recent neuroimaging studies have demonstrated changes in brain function in cognitively normal subjects at increased risk of developing Alzheimer's disease. Amnestic mild cognitive impairment (AMCI) carries a high risk of developing into Alzheimer's disease. In AMCI altered cortical activation has been demonstrated during memory tasks, using functional MRI (fMRI). Memory and attention are closely related cognitive functions. It is unclear whether the memory impairment of AMCI is associated with attentional deficits of the sort likely to be revealed by tasks requiring divided attention. Ten older adults (mean age 72 years, range 57-81 years) with AMCI were compared with healthy matched controls on divided attention and passive sensory processing tasks using fMRI. During the divided attention task both groups activated similar regions of left hemispheric prefrontal and extrastriate visual cortex. However, the AMCI group had attenuated prefrontal activation compared with age matched controls. On the passive sensory processing task there was no difference between the AMCI and control groups. We conclude that there are changes in the functional network subserving divided attention in patients with AMCI as reflected in the attenuation of prefrontal cortical activation. These findings have implications for evaluating cognition in AMCI and also for monitoring the effects of future treatments in AMCI.