Perceptual narrowing is a domain-general process in which infants move from a broad sensitivity to a wide range of stimuli to developing expertise within often experienced native stimuli (Maurer & Werker, 2014). One outcome of this is the own-race bias, characterized by an increasing difficulty in discriminating other-race faces with age and experience for those raised in a racially homogenous environment (Anzures, Quinn, Pascalis, Slater, Tanaka, & Lee, 2013). Theorists have proposed that this is due to a categorization-individuation process, wherein infants begin to categorize non-native stimuli but continue to individuate native stimuli (Hugenberg, Young, Bernstein, & Sacco, 2010; Nelson, 2001). Exposure to multiple exemplars during initial learning has been found to facilitate infant categorization of other-species faces while exposure to a single exemplar does not (Dixon, Reynolds, Romano, Roth, Stumpe, Guy, & Mosteller, 2019). The goal of this study was to investigate the effects of initial learning conditions on infants' ability to individuate and categorize own- and other-race faces. Ten-month-old infants were familiarized with a single exemplar or multiple exemplars of own- or other-race faces. Event-related potentials (ERPs) were recorded while infants were presented with the familiar face(s) they were exposed to during familiarization, novel faces from the same race used during familiarization, and novel faces from a race other than the one used in familiarization. Infants familiarized with a single exemplar, regardless of race, showed significant differences in both the Nc component (Negative central, associated with visual attention) and the LSW (late slow wave, associated with recognition memory) between familiar and novel faces at the subordinate-level category of race. No differences were found across familiarization conditions for the P400 component associated with face processing. Infants familiarized with multiple exemplars showed no evidence of discriminating faces at the categorical or individual level. Results suggest that, in contrast to other-species faces, infants at this age may process human faces more efficiently when familiarized with a single exemplar. The implications of the current findings are discussed in relation to the impact of initial learning conditions on infants' ability to individuate and categorize own- and other-species faces and social implications of infants' processing of other-race faces.

知觉缩小是一个领域的一般过程，在这个过程中，婴儿从对各种刺激的广泛敏感性转变为在经常经历的原生刺激中发展专业知识（Maurer & Werker，2014）。其结果之一是本族偏见，其特点是在种族同质环境中长大的人越来越难以区分年龄和经验的其他种族面孔（Anzures、Quinn、Pascalis、Slater、Tanaka 和 Lee，2013 年） . 理论家提出这是由于分类-个体化过程，其中婴儿开始对非原生刺激进行分类，但继续对原生刺激进行个体化（Hugenberg, Young, Bernstein, & Sacco, 2010; Nelson, 2001）。已发现在初始学习期间接触多个样本有助于婴儿对其他物种的面孔进行分类，而接触单一样本则不能（Dixon、Reynolds、Romano、Roth、Stumpe、Guy 和 Mosteller，2019 年）。本研究的目的是调查初始学习条件对婴儿个性化和分类自己和其他种族面孔的能力的影响。十个月大的婴儿熟悉自己或其他种族面孔的单个样本或多个样本。记录事件相关电位 (ERP)，同时向婴儿展示他们在熟悉过程中接触到的熟悉面孔、在熟悉过程中使用来自同一种族的新面孔以及来自与在熟悉过程中使用的种族不同的种族的新面孔. 熟悉单一样本的婴儿，无论种族如何，在从属级别的种族类别中，熟悉和新面孔之间的 Nc 分量（负中心，与视觉注意相关）和 LSW（晚期慢波，与识别记忆相关）都显示出显着差异。在与面部处理相关的 P400 组件的熟悉条件下没有发现差异。熟悉多个样本的婴儿没有表现出在分类或个人层面上区分面孔的证据。结果表明，与其他物种的面孔相比，这个年龄段的婴儿在熟悉单个样本时可能会更有效地处理人脸。讨论了当前发现的影响与初始学习条件对婴儿的影响有关。