Institute of Psychology (IPSY) & Institute of Neuroscience (IoNS), Université catholique de Louvain, Belgium.
Brain Cogn. 2012 Feb;78(1):7-13. doi: 10.1016/j.bandc.2011.10.009. Epub 2011 Nov 17.
In two behavioral experiments involving lateralized stimulus presentation, we tested whether one of the most commonly used measures of holistic face processing-the composite face effect-would be more pronounced for stimuli presented to the right as compared to the left hemisphere. In experiment 1, we investigated the composite face effect in a verbal identification task, similar to its original report (Young, Hellawell, & Hay, 1987). Aligning top and bottom halves of composite face stimuli led to performance decreases irrespective of hemifield, indicating holistic processing of comparable magnitude for inputs provided separately to either hemisphere. However, when matching of the same top parts was required in experiment 2, an alignment-dependent performance decrease was found for stimuli presented in the left, but not right visual field. These observations suggest that the right hemisphere dominates in early stages of holistic processing, as indexed by the composite face effect, but that later processes such as face identification and naming are based on unified representations that are independent of input lateralization. Moreover, the composite face effect may not rely on the exact same representation(s) when measured in matching and identification tasks.
在两项涉及偏侧刺激呈现的行为实验中，我们测试了最常用于整体面孔处理的度量之一——复合面孔效应——是否会在右半球呈现的刺激中比在左半球呈现的刺激更为明显。在实验 1 中，我们在类似于其原始报告（Young、Hellawell 和 Hay，1987）的言语识别任务中研究了复合面孔效应。对齐复合面孔刺激的顶部和底部会导致表现下降，而与视野无关，这表明对于分别提供给两个半球的输入进行了相当大的整体处理。然而，在实验 2 中需要匹配相同的顶部部分时，发现对于在左视野而不是右视野呈现的刺激，存在依赖于对齐的表现下降。这些观察结果表明，右侧大脑半球在整体处理的早期阶段占主导地位，如复合面孔效应所表明的，但后来的过程，如面孔识别和命名，则基于独立于输入偏侧性的统一表示。此外，当在匹配和识别任务中测量时，复合面孔效应可能不依赖于完全相同的表示。
