Perceptual and decisional factors influencing the discrimination of inversion in the Thatcher illusion.

Abstract

The Thatcher illusion (Thompson, 1980) is considered to be a prototypical illustration of the notion that face perception is dependent on configural processes and representations. We explored this idea by examining the relative contributions of perceptual and decisional processes to the ability of observers to identify the orientation of two classes of forms-faces and churches-and a set of their component features. Observers were presented with upright and inverted images of faces and churches in which the components (eyes, mouth, windows, doors) were presented either upright or inverted. Observers first rated the subjective grotesqueness of all of the images and then performed a complete identification task in which they had to identify the orientation of the overall form and the orientation of each of the interior features. Grotesqueness ratings for both classes of image showed the standard modulation of rated grotesqueness as a function of orientation. The complete identification results revealed violations of both perceptual and decisional separability but failed to reveal any violations of within-stimulus (perceptual) independence. In addition, exploration of a simple bivariate Gaussian signal detection model of the relationship between identification performance and judged grotesqueness suggests that within-stimulus violations of perceptual independence on their own are insufficient for producing the illusion. This lack of evidence for within-stimulus configurality suggests the need for a critical reevaluation of the role of configural processing in the Thatcher illusion. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

An examination of the processing capacity of features in the Thatcher illusion

“…The results of the present study should be considered alongside those of Cornes et al (2011). Cornes et al explored the Thatcher illusion within the terms of general recognition theory (GRT), using response frequencies rather than latencies.…”

“…In the Thatcher illusion, faces appear grotesque as a consequence of inverting the eyes and mouth in an otherwise upright face (Bartlett & Searcy, 1993;Cornes, Donnelly, Godwin, & Wenger, 2011;Thompson, 1980). However, the grotesque appearance disappears when Thatcherised faces are inverted.…”

Composite faces are not processed holistically: evidence from the Garner and redundant target paradigms

“…The majority of the composite face studies (Young et al, 1987) belong in that class. In contrast, theoretical definitions of holistic processing, dating at least to O'Toole, Wenger, and Townsend, (2001) include formal, computational, and mathematical models (Wenger & Townsend, 2001a;2001b;Copeland & Wenger, 2006;Cornes et al, 2011;Mestry et al, 2012;Mestry et al, 2014;Donnelly et al, 2012;Fifić & Townsend, 2010;O'Toole et al, 2001;Wenger & Ingvalson, 2002;Fitousi & Wenger, 2013;Fitousi, 2013). These accounts avoid circularity and are open to falsification because they rely on explicit and well-defined processing models of independence.…”

“…The face stimuli for all the experiments were initially published as part of Cornes et al (2011). The stimuli for Experiment 1 consisted of a sample of four aligned composite faces and their four complementary misaligned versions (cf.…”

Indecision on decisional separability

“…Illustrating this problem seems particularly important considering that the vast majority of studies that apply the MSDA framework find evidence for violations of DS, sometimes in cases where such violations seem counterintuitive (Amazeen & DaSilva, 2005;Farris et al, 2010;Oberle & Amazeen, 2003;Valdez & Amazeen, 2008;Wenger & Ingvalson, 2002, 2003 including some of our own work . All of these studies employed MSDA methods similar to the approaches we used here (Kadlec & Townsend, 1992;Kadlec, 1995Kadlec, , 1999, one of these studies included additional tests of diagonal d' (Wenger & Ingvalson, 2003), and a few included converging model-fitting methods (Copeland & Wenger, 2006;Cornes, Donnelly, Godwin, & Wenger, 2010;Valdez & Amazeen, 2008).…”