Abstract
Recent evidence suggests that the structure conveyed by horizontally-oriented spatial frequency components is maximally diagnostic for face identity, and that selective processing of this structure is correlated with face identification performance (Pachai et al, Front Psychol, 2013). Given that processing of facial information for identification and discrimination is more efficient for personally familiar than unfamiliar faces (e.g., Bruce et al, JEP:A, 1999; Ramon, PeerJ, 2015; Ramon & Van Belle, PeerJ, in press), we hypothesized that personal familiarity would be associated with higher horizontal selectivity in a face identification task. To assess this hypothesis, we recruited observers from the University of Glasgow and McMaster University to complete an identification task using members of the School of Psychology at University of Glasgow as stimuli. These two groups were matched in age, sex, and years of education, differing only in their personal familiarity with the stimuli. Across trials, we presented upright or inverted faces that were horizontally or vertically-filtered with bandwidths ranging from 15-180°. For each observer, we fit psychometric functions relating proportion correct to the entire range of filter bandwidths, separately for each face and filter orientation. From these fits, we defined horizontal selectivity as the difference between horizontal and vertical filters from 15-90°, where 90° represents the maximum independent bandwidth, and overall identification accuracy as performance with 180° filters, where 180° represents unfiltered stimuli. Our results revealed higher identification accuracy for familiar faces than unfamiliar, with a non-significant effect of familiarity on the difference between upright and inverted stimuli. We also found higher horizontal selectivity for familiar faces than unfamiliar, but only when the stimuli were upright. Together, these results suggest that personal familiarity increases the selective processing of horizontal structure from face stimuli, particularly when the faces are presented at the canonical orientation encountered during everyday life.
Meeting abstract presented at VSS 2016