Neuroimaging Center, University of Groningen, Groningen, The Netherlands.
PLoS One. 2010 Dec 7;5(12):e15280. doi: 10.1371/journal.pone.0015280.
Most people show a remarkable deficit to report the second of two targets when presented in close temporal succession, reflecting an attentional blink (AB). An aspect of the AB that is often ignored is that there are large individual differences in the magnitude of the effect. Here we exploit these individual differences to address a long-standing question: does attention to a visual target come at a cost for attention to an auditory target (and vice versa)? More specifically, the goal of the current study was to investigate a) whether individuals with a large within-modality AB also show a large cross-modal AB, and b) whether individual differences in AB magnitude within different modalities correlate or are completely separate.
METHODOLOGY/PRINCIPAL FINDINGS: While minimizing differential task difficulty and chances for a task-switch to occur, a significant AB was observed when targets were both presented within the auditory or visual modality, and a positive correlation was found between individual within-modality AB magnitudes. However, neither a cross-modal AB nor a correlation between cross-modal and within-modality AB magnitudes was found.
CONCLUSION/SIGNIFICANCE: The results provide strong evidence that a major source of attentional restriction must lie in modality-specific sensory systems rather than a central amodal system, effectively settling a long-standing debate. Individuals with a large within-modality AB may be especially committed or focused in their processing of the first target, and to some extent that tendency to focus could cross modalities, reflected in the within-modality correlation. However, what they are focusing (resource allocation, blocking of processing) is strictly within-modality as it only affects the second target on within-modality trials. The findings show that individual differences in AB magnitude can provide important information about the modular structure of human cognition.
当两个目标在时间上紧密相继呈现时，大多数人都会明显地难以报告第二个目标，这反映了注意瞬脱（AB）的现象。AB 经常被忽视的一个方面是，个体之间的效应大小存在很大差异。在这里，我们利用这些个体差异来解决一个长期存在的问题：当注意一个视觉目标时，是否会对听觉目标的注意产生代价（反之亦然）？更具体地说，当前研究的目标是调查：a）具有较大的同模态 AB 的个体是否也表现出较大的跨模态 AB；b）不同模态中 AB 大小的个体差异是否相关或完全独立。
方法/主要发现：在尽量减少任务难度差异和任务切换机会的情况下，当目标都在听觉或视觉模态中呈现时，观察到了显著的 AB，并且在个体的同模态 AB 大小之间发现了正相关。然而，既没有跨模态 AB，也没有跨模态和同模态 AB 大小之间的相关性。
结论/意义：结果提供了强有力的证据，表明注意力限制的主要来源必须位于模态特异性感觉系统中，而不是中央非模态系统中，有效地解决了一个长期存在的争论。具有较大的同模态 AB 的个体可能在处理第一个目标时特别专注或聚焦，并且在某种程度上，这种聚焦的倾向可能跨越模态，体现在同模态相关性中。然而，他们专注的（资源分配、处理阻塞）是严格的同模态，因为它只影响同模态试验中的第二个目标。这些发现表明，AB 大小的个体差异可以提供关于人类认知模块化结构的重要信息。
