Center for Noninvasive Brain Stimulation, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA.
J Neurosci. 2010 Jan 13;30(2):650-4. doi: 10.1523/JNEUROSCI.4592-09.2010.
Humans have a prodigious capacity to perform multiple tasks simultaneously. Being distracted while, for example, performing a complex motor skill adds complexity to a task and thus leads to a performance impairment. Yet, it may not be just the presence or absence of a distraction that affects motor performance. Instead, the characteristics of the distraction may play a critical role in affecting human motor performance. Here, we show that performance of a motor sequence can be substantially enhanced by simultaneously learning an independent color sequence. In contrast, performance of the same motor sequence was impaired by concurrently counting the number of red cues that were in the color sequence. The color and motor sequences had different lengths (10 vs 12 items), different numbers of elements (five vs four elements), and different temporal patterns (randomly intermittent vs continuous) and thus were independent of one another. These observations show that distracting information does not always impair motor performance, and so is not a sufficient explanation for the impaired performance. Instead, the influence that a distraction exerts upon performance is mediated by the type of processes engaged: when similar core processes are engaged, motor performance is enhanced, whereas when very different processes are engaged (i.e., counting and sequence performance), performance is impaired. Thus, these observations deepen our understanding of how a distraction, depending on its characteristics, can either impair or enhance performance and may offer novel approaches to optimizing human cognition.
人类具有同时执行多项任务的非凡能力。例如，在执行复杂的运动技能时分心会增加任务的复杂性，从而导致表现受损。然而，影响运动表现的可能不仅仅是分心的存在与否。相反，分心的特征可能在影响人类运动表现方面起着至关重要的作用。在这里，我们表明，通过同时学习独立的颜色序列，可以大大提高运动序列的表现。相比之下，通过同时计算颜色序列中红色提示的数量，相同的运动序列的表现会受到损害。颜色和运动序列的长度不同（10 项对 12 项），元素数量不同（5 个对 4 个元素），时间模式也不同（随机间歇对连续），因此彼此独立。这些观察结果表明，分心信息并不总是会损害运动表现，因此不能充分解释表现受损的原因。相反，分心对表现的影响是由所涉及的过程类型介导的：当涉及相似的核心过程时，运动表现会增强，而当涉及非常不同的过程时（即计数和序列表现），表现会受损。因此，这些观察加深了我们对分心如何根据其特征损害或增强表现的理解，并可能为优化人类认知提供新的方法。
