title: Orientation-sensitivity to facial features explains the Thatcher illusion.
abstract: The Thatcher illusion provides a compelling example of the perceptual cost of face inversion. The Thatcher illusion is often thought to result from a disruption to the processing of spatial relations between face features. Here, we show the limitations of this account and instead demonstrate that the effect of inversion in the Thatcher illusion is better explained by a disruption to the processing of purely local facial features. Using a matching task, we found that participants were able to discriminate normal and Thatcherized versions of the same face when they were presented in an upright orientation, but not when the images were inverted. Next, we showed that the effect of inversion was also apparent when only the eye region or only the mouth region was visible. These results demonstrate that a key component of the Thatcher illusion is to be found in orientation-specific encoding of the expressive features (eyes and mouth) of the face.
authors.affiliation: Department of Psychology and York Neuroimaging Centre, University of York, York, UK.
authors.forename: Lilia
authors.initials: L
authors.lastname: Psalta
authors.affiliation: Department of Psychology and York Neuroimaging Centre, University of York, York, UK.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Young
authors.affiliation: Department of Psychology and York Neuroimaging Centre, University of York, York, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Thompson
authors.affiliation: Department of Psychology and York Neuroimaging Centre, University of York, York, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Andrews
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004192:Discrimination, Psychological / Q000502:physiology; D004644:Emotions / Q000502:physiology; D005145:Face; D005260:Female; D006801:Humans; D007088:Illusions / Q000502:physiology*; D007600:Judgment / Q000502:physiology; D008297:Male; D009949:Orientation / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D055815:Young Adult
keywords: Thatcher illusion; expression; face; inversion