title: Development and aging of visual hemifield asymmetries in contrast sensitivity.
abstract: The relation of development and aging with models of visual anisotropies and their influence on low-level visual processing remain to be established. Our main goal was to explore visual performance asymmetries in development and normal aging using low-level contrast sensitivity behavioral tasks [probing two distinct spatiotemporal frequency channels, (a) intermediate spatial and null temporal frequency (3.5 cycles per degree (cpd) and 0 Hz); and (b) low spatial and high temporal frequency (0.25 cpd undergoing 25 Hz counterphase flicker)]. Different patterns of functional asymmetries were investigated within four (two neurodevelopmental and two adult) age groups (N = 258 participants; 8-65 years). We found a left visual hemifield/right hemisphere advantage for only the intermediate spatial frequency channel that was present early in life and remained stable throughout adulthood. In contrast, inferior/superior visual hemifield asymmetries, with a direct ecological meaning, were found for both spatiotemporal frequency channels. This inferior visual hemifield advantage emerged early in life and persisted throughout aging. These findings show that both right hemispheric and dorsal retinotopic patterns of dominance in low-level vision emerge early in childhood, maintaining during aging.
authors.affiliation: Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Maria Fatima
authors.initials: MF
authors.lastname: Silva
authors.affiliation: Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal ICNAS, University of Coimbra, Coimbra, Portugal.
authors.forename: Otília C
authors.initials: OC
authors.lastname: d'Almeida
authors.affiliation: Laboratory of Biostatistics and Medical Informatics, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Oliveiros
authors.affiliation: Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Mateus
authors.affiliation: Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal ICNAS, University of Coimbra, Coimbra, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Castelo-Branco
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D016880:Anisotropy; D002648:Child; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D005425:Flicker Fusion / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult
keywords: aging; asymmetry; contrast sensitivity; development; visual field