Developmental Cognitive Neuroscience Lab, Department of Psychological and Brain Sciences, Indiana University Bloomington, IN, USA.
Front Psychol. 2013 Mar 18;4:117. doi: 10.3389/fpsyg.2013.00117. eCollection 2013.
Infant ERP studies often feature high attrition rates with large numbers of trials excluded from statistical analyses. The number of experimental conditions is conventionally limited to reduce the test-sessions' durations and to ensure that reasonable trial-numbers will be obtained for each condition. Here, we designed an ERP study involving eight conditions originating from three previously published studies and presented them to 18 1-year-olds. We expected to replicate original results at least partly. Additionally, we were interested in the effect this novel method of stimulus presentation would have on infant attention. Due to the requirement for sustained attention, interest may decrease. Alternatively, the stimulus-variability may extend attention, allowing the acquisition of more valid trials. Our main finding was that the variability of the stimulus presentation sustained the infants' attention beyond normal parameters. This is apparent from the markedly increased number of artifact-free trials obtained and from the substantially decreased attrition rates. Results from a gap-/no gap-task were fully replicated whereas others, related to face-processing, were replicated in part. Additionally, effects that were not reported in the original studies were found. This is most probably due to interference in the information processing between these conditions. The results show that presenting infants with varied stimuli extends their attention, allowing the acquisition of at least four times more data than via current infant ERP methods. However, stimuli from separate sub-experiments must be cognitively and perceptually distinct, otherwise contamination between related factors will occur.
婴儿 ERP 研究通常存在较高的淘汰率，大量试验被排除在统计分析之外。传统上，实验条件的数量受到限制，以减少测试阶段的持续时间，并确保为每个条件获得合理的试验数量。在这里，我们设计了一项涉及三个先前发表的研究的八个条件的 ERP 研究，并将其呈现给 18 名 1 岁婴儿。我们希望至少部分复制原始结果。此外，我们还对这种新的刺激呈现方法对婴儿注意力的影响感兴趣。由于需要持续注意力，兴趣可能会降低。或者，刺激的可变性可能会延长注意力，从而获得更多有效的试验。我们的主要发现是，刺激呈现的可变性使婴儿的注意力保持在正常参数之外。这从获得的明显更多的无伪迹试验数量和大大降低的淘汰率中可以明显看出。缺口/无缺口任务的结果得到了完全复制，而与面部处理相关的其他结果则部分得到了复制。此外，还发现了在原始研究中没有报告的效果。这很可能是由于这些条件之间的信息处理存在干扰。结果表明，向婴儿呈现多样化的刺激可以延长他们的注意力，从而获得的数据量至少是当前婴儿 ERP 方法的四倍。然而，来自不同子实验的刺激必须在认知和感知上有所区别，否则相关因素之间会发生干扰。
