Adaptation to Antifaces and the Perception of Correct Famous Identity in an Average Face

Abstract

Previous experiments have examined exposure to anti-identities (faces that possess traits opposite to an identity through a population average), finding that exposure to antifaces enhances recognition of the plus-identity images. Here we examine adaptation to antifaces using famous female celebrities. We demonstrate: that exposure to a color and shape transformed antiface of a celebrity increases the likelihood of perceiving the identity from which the antiface was manufactured in a composite face and that the effect shows size invariance (experiment 1), equivalent effects are seen in internet and laboratory-based studies (experiment 2), adaptation to shape-only antifaces has stronger effects on identity recognition than adaptation to color-only antifaces (experiment 3), and exposure to male versions of the antifaces does not influence the perception of female faces (experiment 4). Across these studies we found an effect of order where aftereffects were more pronounced in early than later trials. Overall, our studies delineate several aspects of identity aftereffects and support the proposal that identity is coded relative to other faces with special reference to a relatively sex-specific mean face representation.

Early temporal negativity is sensitive to perceived (rather than physical) facial identity

“…The findings by Little et al (2012) are in potential contrast with a series of recent experiments suggesting that although shape does play a role in the initial encoding of unfamiliar faces, shape is remarkably unimportant in the recognition of familiar faces (Hole, George, Eaves, & Rasek, 2002;Kaufmann, Schulz, & Schweinberger, 2013;Kaufmann & Schweinberger, 2008).…”

“…However, since their face-morphing algorithm used alterations in both shape and reflectance, they did not demonstrate that their effects of anti-face adaptation reflected an altered perception of shape specifically. A more recent study by Little et al (2012) investigated the recognition of celebrities' faces that were preceded by different kinds of anti-faces that could be (1) shape and reflectance-transformed (as in Leopold et al, 2001), (2) had average reflectance but were shape-transformed to form an anti-shape image, or (3) had average shape but were reflectancetransformed to form an anti-reflectance image. Little et al found that anti-shape adaptors had a stronger effect on identity recognition than anti-reflectance adaptors, supporting Leopold´s original interpretation.…”

“…These authors investigated contrastive aftereffects caused by adaptation, and showed that adaptation to specific face images caused effects that were confined to a particular identity vector or trajectory ( Figure 1). Adaptation to an "anti-face" (a face that deviates from the norm in exactly opposite direction as a real face) elicited an illusion, in which an average probe face tended to be identified as the familiar face on the same trajectory -strongly suggesting that the mental representations of a face and its anti-face were linked via a common trajectory through the norm face (see also Leopold, Rhodes, Muller, & Jeffery, 2005;Little, Hancock, DeBruine, & Jones, 2012;Rhodes & Jeffery, 2006;Tsao & Freiwald, 2006).…”

Aftereffects in face processing

“…This highlights the importance of ruling out lower-level explanations when considering face aftereffects, especially since aftereffects can occur at any level of the visual pathway (Thillman and Webster, 2012). More generally, Little et al (2012) have shown that the FIAE is primarily based on face shape information rather than color information.…”

“…Little et al (2012) have shown that these aftereffects are equivalent for laboratory based studies and studies conducted on the internet. These authors also noted that the aftereffects were stronger during the earlier trials during the post-adaptation test.…”