Hampshire Adam, Gruszka Aleksandra, Fallon Sean J, Owen Adrian M
MRC Cognition and Brain Sciences Unit, Cambridge, UK.
J Cogn Neurosci. 2008 Sep;20(9):1670-86. doi: 10.1162/jocn.2008.20115.
Studies of the aging brain have demonstrated that areas of the frontal cortex, along with their associated top-down executive control processes, are particularly prone to the neurodegenerative effects of age. Here, we investigate the effects of aging on brain and behavior using a novel task, which allows us to examine separate components of an individual's chosen strategy during routine problem solving. Our findings reveal that, contrary to previous suggestions of a specific decrease in cognitive flexibility, older participants show no increased level of perseveration to either the recently rewarded object or the recently relevant object category. In line with this lack of perseveration, lateral and medial regions of the orbito-frontal cortex, which are associated with inhibitory control and reward processing, appear to be functionally intact. Instead, a general loss of efficient problem-solving strategy is apparent with a concomitant decrease in neural activity in the ventrolateral prefrontal cortex and the posterior parietal cortex. The dorsolateral prefrontal cortex is also affected during problem solving, but age-related decline within this region appears to occur at a later stage.
对衰老大脑的研究表明，额叶皮质区域及其相关的自上而下的执行控制过程特别容易受到年龄的神经退行性影响。在此，我们使用一项新颖的任务来研究衰老对大脑和行为的影响，该任务使我们能够在日常问题解决过程中检查个体所选策略的各个组成部分。我们的研究结果显示，与之前关于认知灵活性特定下降的观点相反，老年参与者对最近得到奖励的物体或最近相关的物体类别并没有表现出更高的固执程度。与这种缺乏固执性相一致的是，与抑制控制和奖励处理相关的眶额皮质的外侧和内侧区域在功能上似乎是完整的。相反，有效的问题解决策略普遍丧失，同时腹外侧前额叶皮质和顶叶后皮质的神经活动也随之减少。背外侧前额叶皮质在问题解决过程中也会受到影响，但该区域与年龄相关的衰退似乎发生在后期。
