title: Perceptual bias, more than age, impacts on eye movements during face processing.
abstract: Consistent with the right hemispheric dominance for face processing, a left perceptual bias (LPB) is typically demonstrated by younger adults viewing faces and a left eye movement bias has also been revealed. Hemispheric asymmetry is predicted to reduce with age and older adults have demonstrated a weaker LPB, particularly when viewing time is restricted. What is currently unclear is whether age also weakens the left eye movement bias. Additionally, a right perceptual bias (RPB) for facial judgments has less frequently been demonstrated, but whether this is accompanied by a right eye movement bias has not been investigated. To address these issues older and younger adults' eye movements and gender judgments of chimeric faces were recorded in two time conditions. Age did not significantly weaken the LPB or eye movement bias; both groups looked initially to the left side of the face and made more fixations when the gender judgment was based on the left side. A positive association was found between LPB and initial saccades in the freeview condition and with all eye movements (initial saccades, number and duration of fixations) when time was restricted. The accompanying eye movement bias revealed by LPB participants contrasted with RPB participants who demonstrated no eye movement bias in either time condition. Consequently, increased age is not clearly associated with weakened perceptual and eye movement biases. Instead an eye movement bias accompanies an LPB (particularly under restricted viewing time conditions) but not an RPB.
authors.affiliation: School of Psychological Sciences and Health, University of Strathclyde, 40 George Street, Glasgow G1 1QE, UK. Electronic address: louise.williams@strath.ac.uk.
authors.forename: Louise R
authors.initials: LR
authors.lastname: Williams
authors.affiliation: School of Psychological Sciences and Health, University of Strathclyde, 40 George Street, Glasgow G1 1QE, UK.
authors.forename: Madeleine A
authors.initials: MA
authors.lastname: Grealy
authors.affiliation: School of Psychological Sciences and Health, University of Strathclyde, 40 George Street, Glasgow G1 1QE, UK.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Kelly
authors.affiliation: School of Psychological Sciences and Health, University of Strathclyde, 40 George Street, Glasgow G1 1QE, UK.
authors.forename: Iona
authors.initials: I
authors.lastname: Henderson
authors.affiliation: School of Psychological Sciences and Health, University of Strathclyde, 40 George Street, Glasgow G1 1QE, UK.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Butler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D015331:Cohort Studies; D005133:Eye Movements / Q000502:physiology*; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012438:Saccades / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Ageing; Chimeric faces; Eye movements; Perceptual bias