Halvorson Kimberly M, Hazeltine Eliot
Department of Psychology, Metropolitan State University, Saint Paul, MN, United States.
Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States.
Front Psychol. 2019 Mar 29;10:711. doi: 10.3389/fpsyg.2019.00711. eCollection 2019.
Dual-task costs are often significantly reduced or eliminated when both tasks use compatible stimulus-response (S-R) pairs. Either by design or unintentionally, S-R pairs used in dual-task experiments that produce small dual-task costs typically have two properties that may reduce dual-task interference. One property is that they are easy to keep separate; specifically, one task is often visual-spatial and contains little verbal information and the other task is primarily auditory-verbal and has no significant spatial component. The other property is that the two sets of S-R pairs are often compatible at the set-level; specifically, the collection of stimuli for each task is strongly related to the collection of responses for that task, even if there is no direct correspondence between the individual items in the sets. In this paper, we directly test which of these two properties is driving the absence of large dual-task costs. We used stimuli (images of hands and auditory words) that when previously been paired with responses (button presses and vocal utterances) produced minimal dual-task costs, but we manipulated the shape of the hands in the images and the auditory words. If set-level compatibility is driving efficient performance, then these changes should not affect dual-task costs. However, we found large changes in the dual-task costs depending on the specific stimuli and responses. We conclude that set-level compatibility is not sufficient to minimize dual-task costs. We connect these findings to divisions within the working memory system and discuss implications for understanding dual-task performance more broadly.
当两个任务都使用兼容的刺激-反应（S-R）对时，双任务成本通常会显著降低或消除。无论是有意设计还是无意为之，在产生较小双任务成本的双任务实验中使用的S-R对通常具有两个可能减少双任务干扰的特性。一个特性是它们易于区分；具体来说，一个任务通常是视觉空间的，几乎不包含语言信息，而另一个任务主要是听觉语言的，没有显著的空间成分。另一个特性是两组S-R对在集合层面通常是兼容的；具体来说，每个任务的刺激集合与该任务的反应集合密切相关，即使集合中的单个项目之间没有直接对应关系。在本文中，我们直接测试这两个特性中的哪一个导致了没有大的双任务成本。我们使用了刺激（手的图像和听觉单词），这些刺激在之前与反应（按键和发声）配对时产生的双任务成本最小，但我们对图像中手的形状和听觉单词进行了操纵。如果集合层面的兼容性驱动了高效的表现，那么这些变化应该不会影响双任务成本。然而，我们发现双任务成本根据具体的刺激和反应有很大变化。我们得出结论，集合层面的兼容性不足以最小化双任务成本。我们将这些发现与工作记忆系统中的划分联系起来，并更广泛地讨论了对理解双任务表现的意义。
