System delays are a major factor that harms user experience. Long delays often result in system abandonment, decreased user performance, and lost revenue for businesses. Although studies have provided important contributions on the consequences of delays, less is known about why system delays harm the user experience. Using fMRI, we examined how long system delays—compared to short delays—can change a user’s brain state. Results showed that brain state switching was more likely during a long delay than during a short delay. Brain state switching was also more likely at the beginning of a task following a long delay than following a short delay. The default-mode network (brain regions associated with inattention) was more active during long delays than when users were engaged in the task. Furthermore, long delays were significantly related to worsened performance as measured in decision time in the task following a delay. This effect was mediated by brain state switching at the beginning of the task after the delay. We also attempted four different system design interventions to overcome this and found partial mitigation, but none eliminated the negative effect of delays.

中文翻译：

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信息呈现的延迟会导致大脑状态切换，从而降低用户的性能，而我们对此可能无能为力

系统延迟是损害用户体验的主要因素。长时间的延迟通常会导致系统废弃、用户性能下降以及企业收入损失。尽管研究对延迟的后果做出了重要贡献，但对于系统延迟为何会损害用户体验却知之甚少。使用功能磁共振成像，我们研究了与短延迟相比，系统延迟多长时间可以改变用户的大脑状态。结果表明，长时间延迟期间比短时间延迟期间更容易发生大脑状态切换。大脑状态切换也更有可能发生在长时间延迟后的任务开始时，而不是短时间延迟后。默认模式网络（与注意力不集中相关的大脑区域）在长时间延迟期间比用户参与任务时更加活跃。此外，长时间的延迟与性能恶化显着相关，这通过延迟后任务的决策时间来衡量。这种效应是由延迟后任务开始时的大脑状态切换介导的。我们还尝试了四种不同的系统设计干预措施来克服这个问题，并找到了部分缓解措施，但没有一个能够消除延迟的负面影响。