Department of General Psychology, University of Jena, Jena, Germany.
Neuroimage. 2011 Feb 14;54(4):3021-7. doi: 10.1016/j.neuroimage.2010.10.075. Epub 2010 Oct 31.
According to the perceptual load theory, processing of a task-irrelevant distractor is abolished when attentional resources are fully consumed by task-relevant material. As an exception, however, famous faces have been shown to elicit repetition modulations in event-related potentials - an N250r - despite high load at initial presentation, suggesting preserved face-encoding. Here, we recorded N250r repetition modulations by unfamiliar faces, hands, and houses, and tested face specificity of preserved encoding under high load. In an immediate (S1-S2) repetition priming paradigm, participants performed a letter identification task on S1 by indicating whether an "X" vs. "N" was among 6 different (high load condition) or 6 identical (low load condition) letters. Letter strings were superimposed on distractor faces, hands, or houses. Subsequent S2 probes were either identical repetitions of S1 distractors, non-repeated exemplars from the same category, or infrequent butterflies, to which participants responded. Independent of attentional load at S1, an occipito-temporal N250r was found for unfamiliar faces. In contrast, no repetition-related neural modulation emerged for houses or hands. This strongly suggests that a putative face-selective attention module supports encoding under high load, and that similar mechanisms are unavailable for other natural or artificial objects.
根据知觉负载理论，当任务相关材料完全消耗注意力资源时，对任务无关分心物的处理就会被消除。然而，作为一个例外，尽管在初始呈现时负载很高，但著名的面孔会在事件相关电位中引起重复调制——N250r，这表明对面孔的编码得到了保留。在这里，我们记录了不熟悉的面孔、手和房子的 N250r 重复调制，并在高负载下测试了保留编码的面孔特异性。在即时（S1-S2）重复启动范式中，参与者在 S1 上执行字母识别任务，通过指示“X”与“N”是否在 6 个不同的字母（高负载条件）或 6 个相同的字母（低负载条件）中进行判断。字母串叠加在分心面孔、手或房子上。随后的 S2 探针要么是 S1 分心物的相同重复，要么是来自同一类别的非重复示例，要么是不常见的蝴蝶，参与者对此做出反应。无论 S1 时的注意力负载如何，都可以在不熟悉的面孔上找到枕颞部 N250r。相比之下，对于房屋或手，没有出现与重复相关的神经调制。这强烈表明，一个假定的面孔选择性注意模块支持在高负载下的编码，而对于其他自然或人工物体，则没有类似的机制。
