We investigated aging effects in a task-switch paradigm with degraded stimuli administered to college students, 61-74 year olds, and 75-89 year olds. We studied switch costs (the performance difference between task-repeat and task-switch trials) in terms of accuracy and mean reaction times (RTs). Previous aging research focused on switch costs in terms of mean RTs (with accuracy at ceiling). Our results emphasize the importance of distinguishing between switch costs indexed by accuracy and by RTs because these measures lead to different interpretations. We used the Diffusion Decision Model (DDM; Ratcliff, 1978) to study the cognitive components contributing to switch costs. The DDM decomposed the cognitive process of task switching into multiple components. Two parameters of the model, the quality of evidence on which decisions were based (drift rate) and the duration of processes outside the decision process (nondecision time component), indexed different sources of switch costs. We found that older participants had larger switch costs indexed by nondecision time component than younger participants. This result suggests age-related deficits in preparatory cognitive processes. We also found group differences in switch costs indexed by drift rate for switch trials with high stimulus interference (stimuli with features relevant for both tasks). This result suggests that older participants have less effective cognitive processes involved in resolving interference. Our findings show that age-related effects in separate components of switch costs can be studied with the DDM. Our results demonstrate the utility of using discrimination tasks with degraded stimuli in conjunction with model-based analyses. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

中文翻译：

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具有扩散决策模型的任务切换范式中老化的影响。

我们通过对大学生、61-74 岁和 75-89 岁的学生实施降级刺激，研究了任务切换范式中的衰老效应。我们在准确性和平均反应时间 (RT) 方面研究了切换成本（任务重复和任务切换试验之间的性能差异）。以前的老化研究集中在平均 RT 方面的转换成本（准确度在上限）。我们的结果强调区分由准确性和 RT 索引的转换成本的重要性，因为这些措施会导致不同的解释。我们使用扩散决策模型（DDM；Ratcliff，1978）来研究导致转换成本的认知成分。DDM 将任务切换的认知过程分解为多个组件。模型的两个参数，决策所依据的证据质量（漂移率）和决策过程之外的过程持续时间（非决策时间部分），索引了转换成本的不同来源。我们发现年长的参与者比年轻的参与者有更大的转换成本，这些成本由非决策时间组成。这一结果表明准备认知过程中存在与年龄相关的缺陷。我们还发现，对于具有高刺激干扰（具有与两项任务相关的特征的刺激）的转换试验，转换成本的组差异由漂移率索引。这一结果表明，年龄较大的参与者在解决干扰方面的认知过程效率较低。我们的研究结果表明，可以使用 DDM 研究转换成本的不同组成部分中与年龄相关的影响。我们的结果证明了使用具有退化刺激的判别任务与基于模型的分析相结合的实用性。（PsycInfo 数据库记录 (c) 2020 APA，保留所有权利）。