Crowding for faces is determined by visual (not holistic) similarity: Evidence from judgements of eye position

Alexandra V. Kalpadakis-Smith*, Valerie Goffaux, John A. Greenwood

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Web of Science)

Abstract

Crowding (the disruption of object recognition in clutter) presents the fundamental limitation on peripheral vision. For simple objects, crowding is strong when target/flanker elements are similar and weak when they differ - a selectivity for target-flanker similarity. In contrast, the identification of upright holistically-processed face stimuli is more strongly impaired by upright than inverted flankers, whereas inverted face-targets are impaired by both - a pattern attributed to an additional stage of crowding selective for "holistic similarity" between faces. We propose instead that crowding is selective for target-flanker similarity in all stimuli, but that this selectivity is obscured by task difficulty with inverted face-targets. Using judgements of horizontal eye-position that are minimally affected by inversion, we find that crowding is strong when target-flanker orientations match and weak when they differ for both upright and inverted face-targets. By increasing task difficulty, we show that this selectivity for target-flanker similarity is obscured even for upright face-targets. We further demonstrate that this selectivity follows differences in the spatial order of facial features, rather than "holistic similarity" per se. There is consequently no need to invoke a distinct stage of holistic crowding for faces - crowding is selective for target-flanker similarity, even with complex stimuli such as faces.
Original languageEnglish
Article number12556
Number of pages14
JournalScientific Reports
Volume8
DOIs
Publication statusPublished - 22 Aug 2018

Keywords

  • PERIPHERAL-VISION
  • SPATIAL INTERACTION
  • EXTERNAL FEATURES
  • UNFAMILIAR FACES
  • RECOGNITION
  • PERCEPTION
  • AREA
  • SELECTIVITY
  • STIMULI
  • CONFIGURATIONS

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