Behavioural and electrophysiological investigations of individual differences in dual-task attention costs

在我们的日常生活中，我们经常同时做两件事，或者试图一次处理多件事（例如，开车时打电话）。我们一心多用的愿望往往与我们在任何给定时间内所能处理的信息量有限这一事实相冲突。当我们同时执行两项需要注意力的任务时，其中一项或两项任务的表现往往会受到影响。为了研究多任务处理的困难，在我的实验室里，视觉刺激如字母在计算机屏幕上的同一位置快速连续呈现。两个目标作为信息流的一部分呈现，这两个目标之间的时间间隔从不足十分之一秒到几乎两秒不等。参与者被要求报告这两个目标。测量目标1和目标2的行为反应准确性。对目标2的反应显示，当目标在时间上紧密地放在一起时，准确度会明显下降——这种现象被称为注意力闪烁（attention blink， AB）。最近的研究表明，AB的大小在个体之间是不同的，但对于同一个体来说，AB的大小随着时间的推移相对稳定。我的实验室最近的工作表明，AB大小的个体差异可以通过各种性格、脑电波和认知表现指标来预测。我认为AB大小的个体差异源于个体的注意焦点和投资差异，并受到前扣带皮层驱动的表现监测的调节。拟议研究的目标是记录大脑和行为测量，并在一系列研究项目中使用个体差异方法来测试这种概念化。这种创新的个体差异理解AB的方法，结合生理测量的使用，将帮助我们理解为什么有些人比其他人更能克服双任务注意成本。这不仅将提供对AB的潜在本质的洞察，而且可能帮助我们深入了解人类注意力处理调制，这可能是使用其他方法难以实现的。这些知识可以帮助我们找到减少日常生活中这些成本的成功策略。

In our daily lives we often perform two tasks at once, or try to attend to more than one thing at a time (for example, talking on a cell phone while driving). Our desire to multi-task often conflicts with the fact that there are limits on how much information we can attend to at any given time. When we perform two attention-demanding tasks at the same time, performance on one or both tasks often suffers. To investigate multi-tasking difficulties, in my lab visual stimuli such as letters are presented in rapid succession in the same location on the computer screen. Two targets are presented as part of the stream of information, and the time interval between these two targets varies from less than one-tenth of a second to almost two seconds. Participants are asked to report both of the targets. Behavioural response accuracy to target 1 and target 2 are measured. Responses to target 2 show a marked decreased in accuracy when targets are presented closely together in time - a phenomenon known as the attentional blink (AB). Recent research has shown that the size of the AB differs across individuals, but is relatively stable across time for the same individual. Recent work from my lab has shown that individual differences in the size of the AB are predicted by various dispositional, brain-wave, and cognitive performance measures. I suggest that individual differences in AB size result from individual differences in attentional focus and investment, as modulated by anterior cingulate cortex driven performance monitoring. The goal of the proposed research is to record both brain and behavioural measures and to use an individual differences approach to test this conceptualization in a series of research projects. This innovative individual differences approach to understanding AB, combined with the use of physiological measures, will help us understand why some individuals are better able to overcome dual-task attention costs than others. This will not only provide insight into the underlying nature of the AB, but may help us arrive at insights into human attentional processing modulations that may be difficult to achieve using other approaches. This knowledge may help us to lead to successful strategies for reducing these costs in our daily life.