title: Aftereffects support opponent coding of face gender.
abstract: Many aspects of faces derived from structural information appear to be neurally represented using norm-based opponent coding. Recently, however, Zhao, Seriès, Hancock, and Bednar (2011) have argued that another aspect with a strong structural component, namely face gender, is instead multichannel coded. Their conclusion was based on finding that face gender aftereffects initially increased but then decreased for adaptors with increasing levels of gender caricaturing. Critically, this interpretation rests on the untested assumption that caricaturing the differences between male and female composite faces increases perceived sexual dimorphism (masculinity/femininity) of faces. We tested this assumption in Study 1 and found that it held for male, but not female faces. A multichannel account cannot, therefore, be ruled out, although a decrease in realism of adaptors was observed that could have contributed to the decrease in aftereffects. However, their aftereffects likely reflect low-level retinotopic adaptation, which was not minimized for most of their participants. In Study 2 we minimized low-level adaptation and found that face gender aftereffects were strongly positively related to the perceived sexual dimorphism of adaptors. We found no decrease for extreme adaptors, despite testing adaptors with higher perceived sexual dimorphism levels than those used by Zhao et al. These results are consistent with opponent coding of higher-level dimensions related to the perception of face gender.
authors.affiliation: ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, Crawley, WA, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Pond
authors.forename: Nadine
authors.initials: N
authors.lastname: Kloth
authors.forename: Elinor
authors.initials: E
authors.lastname: McKone
authors.forename: Linda
authors.initials: L
authors.lastname: Jeffery
authors.forename: Jessica
authors.initials: J
authors.lastname: Irons
authors.forename: Gillian
authors.initials: G
authors.lastname: Rhodes
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000293:Adolescent; D000328:Adult; D005145:Face; D005260:Female; D005366:Figural Aftereffect / Q000502:physiology*; D006801:Humans; D008297:Male; D012727:Sex Characteristics; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: caricaturing; face gender aftereffects; face perception; multichannel coding; norm-based opponent coding