title: The Caledonian face test: A new test of face discrimination.
abstract: This study aimed to develop a clinical test of face perception which is applicable to a wide range of patients and can capture normal variability. The Caledonian face test utilises synthetic faces which combine simplicity with sufficient realism to permit individual identification. Face discrimination thresholds (i.e. minimum difference between faces required for accurate discrimination) were determined in an "odd-one-out" task. The difference between faces was controlled by an adaptive QUEST procedure. A broad range of face discrimination sensitivity was determined from a group (N=52) of young adults (mean 5.75%; SD 1.18; range 3.33-8.84%). The test is fast (3-4 min), repeatable (test-re-test r(2)=0.795) and demonstrates a significant inversion effect. The potential to identify impairments of face discrimination was evaluated by testing LM who reported a lifelong difficulty with face perception. While LM's impairment for two established face tests was close to the criterion for significance (Z-scores of -2.20 and -2.27) for the Caledonian face test, her Z-score was -7.26, implying a more than threefold higher sensitivity. The new face test provides a quantifiable and repeatable assessment of face discrimination ability. The enhanced sensitivity suggests that the Caledonian face test may be capable of detecting more subtle impairments of face perception than available tests.
authors.affiliation: Bradford School of Optometry and Vision Science, University of Bradford, UK. Electronic address: A.Logan@bradford.ac.uk.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Logan
authors.affiliation: Centre for Vision Research, York University, Toronto, Ontario, Canada. Electronic address: franw@yorku.ca.
authors.forename: Frances
authors.initials: F
authors.lastname: Wilkinson
authors.affiliation: Centre for Vision Research, York University, Toronto, Ontario, Canada. Electronic address: hrwilson@yorku.ca.
authors.forename: Hugh R
authors.initials: HR
authors.lastname: Wilson
authors.affiliation: Department of Life Sciences, Glasgow Caledonian University, UK. Electronic address: G.Gordon@gcu.ac.uk.
authors.forename: Gael E
authors.initials: GE
authors.lastname: Gordon
authors.affiliation: Department of Life Sciences, Glasgow Caledonian University, UK. Electronic address: G.Loffler@gcu.ac.uk.
authors.forename: Gunter
authors.initials: G
authors.lastname: Loffler
mesh_terms: D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology*; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time; D021641:Recognition, Psychology; D055815:Young Adult
keywords: Clinical tests; Face discrimination; Face perception; Prosopagnosia; Psychophysics; Synthetic faces