Color vision and luminance discrimination throughout the life span

Throughout the lifespan, humans exhibit varying abilities in perceiving color and luminance with sensitivity peaking at different stages. The interaction between luminance and color perception is likely influenced by the distinct developmental trajectories of the respective visual psychophysical channels. This study aimed to investigate how chromatic noise affects luminance discrimination thresholds in adolescents, young adults, and elderly individuals. Sixty participants with no visual complaints (20/20 or corrected binocular visual acuity, and no indication of color vision impairment in the Ishihara pseudoisochromatic plate test) were divided into three age groups: adolescents (15.7 ± 0.8 years), young adults (20-40 years), and elderly adults (60 + years). Participants underwent a luminance contrast discrimination task with chromatic noise masking using a mosaic stimulus, where four chromatic noise protocols were applied (protan, deutan, tritan, and a no-noise protocol). The results showed that luminance contrast thresholds were significantly elevated with the addition of chromatic noise in all groups compared to those without chromatic masking noise, but adults exhibited smaller differences in thresholds between the conditions with and without noise compared to participants in the adolescent and elderly groups (p < 0.05). The intergroup comparisons revealed that young adults had the lowest thresholds, followed by adolescents and elderly individuals (p ≤ 0.01). Elderly participants exhibited higher luminance thresholds than young adults in all chromatic noise conditions, especially under the tritan protocol. These findings suggest that the maturation of luminance and color interaction is consolidated after adolescence, with sensitivity peaking of the mechanisms of color-luminance interaction in adulthood and declining in the elderly. The study provides insights into the developmental and aging processes of color-luminance interaction mechanisms, highlighting the continued maturation of color processing mechanisms in adolescence and their subsequent decline with age.