AGE DIFFERENCES ON TEST OF FRONTAL LOBE FUNCTION

本项目重点研究健康年轻人和老年人在额叶功能神经心理测试中的认知过程差异。先前的研究表明，这些测试中与年龄有关的显著下降，有强有力的证据表明，工作记忆能力的变化可能是解释这些下降的重要原因。工作记忆需要同时保存和处理有关执行任务所需的刺激、反应和目标的信息的能力。这里提出的主要假设是，老年人在工作记忆中更新信息的能力下降。因此，他们可能对新输入的反应较差，并且无法根据新信息重新组织工作记忆中已经存在的信息。本研究项目包括17个实验，使用三种不同的额叶功能神经心理学测试：延迟反应测试、自有序指向测试和时间顺序记忆测试。具体实验有三个目的：(1)确定工作记忆更新能力的变化是否可以解释这些测试中的年龄差异；(2)确定更新过程的哪些方面对年龄最敏感；(3)排除其他解释。本研究结果对老年人心理状态评估及老年人环境优化设计具有一定的应用价值。然而，更直接的目标是提高我们对正常衰老的认知基础的认识。

This project focuses on the cognitive processes underlying differences between healthy younger and older adults on neuropsychological tests of frontal lobe functioning. Previous research has shown substantial age-related declines on these tests, and there is strong evidence that changes in working memory ability may be important in explaining these declines. Working memory entails the capacity to simultaneously hold and process information about stimuli, responses, and goals needed to carry out a task. The primary hypothesis set forth here is that older adults have a reduced ability to update information in working memory. Thus, they may be less responsive to new input and fail to re-organize information already in working memory in response to new information. This research project includes a set of 17 experiments using three different neuropsychological tests of frontal lobe function: delayed response tests, self-ordered pointing tests, and tests of memory for temporal order. Specific experiments have three aims: (1) to determine whether changes in the ability to update working memory can explain age differences on these tests, (2) to identify which aspects of the updating process are most sensitive to aging; and (3) to rule out alternative explanations. Results of this research have applications for evaluating the psychological status of the elderly and designing optimal environments for them. The more immediate goal, however, is to advance our knowledge of the cognitive basis of normal aging.