Fischer Rico, Fröber Kerstin, Dreisbach Gesine
Department of Psychology, University of Greifswald, Greifswald, Germany.
Department of Experimental Psychology, University of Regensburg, Regensburg, Germany.
Acta Psychol (Amst). 2018 Nov;191:112-123. doi: 10.1016/j.actpsy.2018.09.002. Epub 2018 Sep 21.
Performing two similar tasks at the same time requires the shielding of the prioritized Task 1 from interference of additional Task 2 processing (between-task interference). In the present study we tested how motivational factors such as prospect of reward might drive shifts between increased proactive control, enabling task shielding, and reduced proactive control resulting in relaxed task shielding. In Experiment 1 an instruction-induced prioritization of Task 1 over Task 2 resulted in initially reduced between-task interference. With increasing time on task, however, between-task interference continuously increased, presumably because participants engaged less in proactive control resulting in reduced task shielding. In Experiment 2 the prospect of reward activated proactive control as indicated by reduced between-task interference in the Reward than in the No reward condition. In Experiment 3, we directly compared the performance of a Reward and a No reward group in a between-subject design. Whereas between-task interference again continuously increased over time in the No reward group, indicating a relaxed mode of task shielding, the Reward group displayed constant small between-task interference over time, suggesting maintained high levels of task shielding. Together these findings speak in favor of an impressive flexibility in regulating cognitive control engagement in multitasking situations. This not only shows the capacity for optimization of multitasking performance by motivational incentives but also further supports assumptions of the strategic nature of assumed processing limitations (bottlenecks) in dual-task performance.
同时执行两项相似任务需要将优先级较高的任务1屏蔽起来，以免受到额外任务2处理过程的干扰（任务间干扰）。在本研究中，我们测试了诸如奖励预期等动机因素如何推动在增强主动控制（从而实现任务屏蔽）和减少主动控制（导致任务屏蔽放松）之间的转换。在实验1中，指令诱导任务1优先于任务2，导致任务间干扰最初减少。然而，随着任务时间的增加，任务间干扰持续增加，推测是因为参与者较少参与主动控制，导致任务屏蔽减少。在实验2中，奖励预期激活了主动控制，奖励条件下的任务间干扰比无奖励条件下减少就表明了这一点。在实验3中，我们在被试间设计中直接比较了奖励组和无奖励组的表现。无奖励组的任务间干扰再次随着时间持续增加，表明任务屏蔽模式较为放松，而奖励组随着时间推移表现出持续较小的任务间干扰，表明维持了较高水平的任务屏蔽。这些发现共同表明，在多任务情境中调节认知控制参与方面具有令人印象深刻的灵活性。这不仅显示了通过动机激励优化多任务表现的能力，还进一步支持了关于双重任务表现中假定处理限制（瓶颈）的策略性质的假设。
