Abstract
We examined behavioral and electro-physiological (VEP) changes with aging in the chromatic and achromatic visual pathways. Forty-five subjects, ranging from twenty to eighty-nine years of age, participated. Isoluminance was determined for the L−M and S+(L−M) pathways for each observer. Contrast thresholds were also found for each observer and used to equate contrast across pathways. VEP responses were measured to isoluminant and achromatic sinusoidal gratings (1.0 cpd) that were multiples of threshold (eight times threshold) presented in an onset/offset mode. Colors for the chromatic gratings were chosen to preferentially modulate the L−M and S+(L−M) pathways. Results show that the chromatic pathways aged similarly, but differently from the achromatic pathway. VEP amplitudes decreased and response latencies increased with age in the chromatic pathways. No significant change with age was found for VEP amplitudes or VEP response latencies in the achromatic pathway. Correspondence was found when comparing VEP responses to behavioral responses (perceptual contrast thresholds) across age, suggesting the VEP accurately reflects changes with age in the visual pathways.