Purpose: To evaluate patterns of activation, convergence and divergence of three functional magnetic resonance imaging (fMRI) Working Memory (WM) tasks in two different age groups. We want to understand potential impact of task and subjects’ age on WM activations as well as most important areas with regard to WM functions.Materials and methods: Thirty-five healthy volunteers completed visual, verbal, and novel auditory WM tasks. The subjects were selected from age extremes to depict possible impact of normal aging. The General Linear Model was used to report significant activations and the effect of age group. Contrasts revealed differences in activation between tasks, and Combined Task Analysis was performed to determine common regions of activation across tasks.Results: Most of the observed differences between the tasks were seen in areas that were responsible for feature processing. Frontal regions were mainstay activation areas, regardless of the utilized stimulus. We found an age-related reduction in activity of visual (in visually-presented tasks) and auditory (in auditory task) cortices but an age-related increase in prefrontal cortex for all tasks.Conclusion: Regardless of the type of the task stimuli, frontal regions are the most important activation areas in WM processing. These areas are also main targets of age-related changes with regard to activation patterns. Our results also indicate that prefrontal overactivity in working memory might be a compensatory effort to mask age-related decline in sensory processing.

中文翻译：

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在不同的工作记忆任务中观察到与年龄相关的额叶过度激活：一项 fMRI 研究。

目的：评估两个不同年龄组的三个功能性磁共振成像 (fMRI) 工作记忆 (WM) 任务的激活、收敛和发散模式。我们想了解任务和受试者年龄对 WM 激活以及与 WM 功能相关的最重要领域的潜在影响。材料和方法： 35 名健康志愿者完成了视觉、语言和新的听觉 WM 任务。受试者是从极端年龄中选出的，以描述正常衰老可能产生的影响。一般线性模型用于报告显着的激活和年龄组的影响。对比揭示了任务之间激活的差异，并且执行了组合任务分析以确定跨任务的共同激活区域。结果：大多数观察到的任务之间的差异出现在负责特征处理的区域。无论使用何种刺激，额叶区域都是主要的激活区域。我们发现视觉（在视觉呈现的任务中）和听觉（在听觉任务中）皮质的活动与年龄相关的减少，但所有任务的前额叶皮层的活动与年龄相关的增加。结论：无论任务刺激的类型如何，额叶区域都是 WM 处理中最重要的激活区域。这些区域也是激活模式与年龄相关变化的主要目标。我们的结果还表明，工作记忆中的前额叶过度活跃可能是一种补偿性努力，以掩盖与年龄相关的感觉处理能力下降。