Department of Psychology, Heidelberg University, Heidelberg, Germany.
Face Categorization Lab, UC Louvain, Louvain-la-Neuve, Belgium.
Sci Rep. 2017 Oct 2;7(1):12526. doi: 10.1038/s41598-017-12760-2.
This study investigates categorization of human and ape faces in 9-month-olds using a Fast Periodic Visual Stimulation (FPVS) paradigm while measuring EEG. Categorization responses are elicited only if infants discriminate between different categories and generalize across exemplars within each category. In study 1, human or ape faces were presented as standard and deviant stimuli in upright and inverted trials. Upright ape faces presented among humans elicited strong categorization responses, whereas responses for upright human faces and for inverted ape faces were smaller. Deviant inverted human faces did not elicit categorization. Data were best explained by a model with main effects of species and orientation. However, variance of low-level image characteristics was higher for the ape than the human category. Variance was matched to replicate this finding in an independent sample (study 2). Both human and ape faces elicited categorization in upright and inverted conditions, but upright ape faces elicited the strongest responses. Again, data were best explained by a model of two main effects. These experiments demonstrate that 9-month-olds rapidly categorize faces, and unfamiliar faces presented among human faces elicit increased categorization responses. This likely reflects habituation for the familiar standard category, and stronger release for the unfamiliar category deviants.
本研究采用快速周期视觉刺激（FPVS）范式，同时测量脑电图，研究 9 个月大的婴儿对人类和猿类面孔的分类。只有当婴儿能够区分不同类别，并在每个类别内对范例进行概括时，才会引起分类反应。在研究 1 中，将直立和倒置的试验中呈现的人类或猿类面孔作为标准和偏差刺激。在人类中呈现的直立猿类面孔会引起强烈的分类反应，而呈现的直立人类面孔和倒置的猿类面孔的反应则较小。倒置的偏差人类面孔不会引起分类。数据最好用一个具有物种和方向主效应的模型来解释。然而，低水平图像特征的方差对于猿类类别来说比人类类别更高。为了复制这一发现，在一个独立的样本中（研究 2），匹配了方差以复制这一发现。在直立和倒置条件下，人类和猿类面孔都能引起分类，但直立的猿类面孔引起的反应最强。同样，数据最好用一个具有两个主效应的模型来解释。这些实验表明，9 个月大的婴儿能够快速分类面孔，并且在人类面孔中呈现的不熟悉面孔会引起更强的分类反应。这可能反映了熟悉标准类别的习惯化，以及不熟悉类别偏差的更强释放。
