American Journal of Psychology Spring 2016, Vol. 129, No. 1 pp. 23–35 • © 2016 by the Board of Trustees of the University of Illinois The Face Inversion Effect: Roles of First- and Second-Order Configural Information CIRO CIVILE, ROSSY McLAREN, and IAN P. L. McLAREN University of Exeter The face inversion effect (FIE) is a reduction in recognition performance for inverted faces com- pared with upright faces. Several studies have proposed that a type of configural information, called second-order relational information, becomes more important with increasing expertise and gives rise to the FIE. However, recently it has been demonstrated that it is possible to obtain an FIE with facial features presented in isolation, showing that configural information is not necessary for this effect to occur. In this article we test whether there is a role for configural information in producing the FIE and whether second- or first-order relational information is particularly important. In Experiment 1, we investigated the role of configural information and local feature orientation by using a new type of “Thatcherizing” transformation on our set of faces, aiming to disrupt second-order and local feature orientation information but keeping all first-order properties unaltered. The results showed a significant reduction in the FIE for these “new” Thatcherized faces, but it did not entirely disappear. Experiment 2 confirmed the FIE for new Thatcherized faces, and Experiment 3 establishes that both local feature orientation and first-order relational information have a role in determining the FIE. KEYWORDS: inversion effect, configural information, featural information, Thatcher illusion, face recognition (FIE), which is the disproportionate (relative to other stimuli such as pictures of houses) decrease in recog- nition performance for upside down (inverted) faces relative to upright faces (Yin, 1969). On its discov- ery, the FIE was described as a clear consequence of the specialized mechanisms used in face processing, which explained why the impairment in recognizing upside down faces was signiicantly larger than that for other objects (Yin, 1969). However, Diamond and Carey (1986) provided a new, alternative account of the FIE suggesting that the inversion efect does not relect a face-speciic process. The authors demonstrated that the inversion efect on recognition memory can be as strong with Face recognition is one of the best cognitive skills people have. We generally recognize faces with very little efort, despite large variations in skin tone, view- point, and expression. Discussion of the nature of face perception has been divided into two interpreta- tions: One asserts that a large body of research sup- ports the notion of specialized mechanisms used to process facial stimuli (Rhodes & Tremewan, 1994; Valentine, 1988; Yin, 1969), whereas the other points out that face recognition is actually based on general mechanisms that can also operate for other nonfacial stimuli as well (Diamond & Carey, 1986; Tanaka & Farah, 1991). One of the most robust phenomena, and central to this debate, is the face inversion efect _s _n _l cs AJP 129_1 text.indd 23 11/17/15 10:50 AM