Abstract
Temporal vision, the ability to detect variations in luminance over time, is essential for motion perception. Studies of temporal vision development in infants are few and the results are somewhat contradictory. In particular, some studies show early development of critical flicker fusion frequency (CFF) compared to sensitivity to lower temporal frequencies (TF), whereas others show similar development for low and high TF. To learn more about temporal visual development, we measured full temporal contrast sensitivity functions (TCSF) in young macaque monkeys (Macaca nemestrina). We tested the ability of eleven animals, ages 5 wks to 4 yrs, to detect an unpatterned field of light the luminance of which was sinusoidally modulated over time at a range of TF from 1 to 40 Hz. Four monkeys were tested longitudinally.
The results from the youngest infants showed reduced sensitivity for all TF, and a reduced range of detectable TF. Sensitivity to high and low TF appeared to develop at different rates, with extrapolated CFF measures approaching adult values somewhat earlier than sensitivity to low TF. Also, adult levels of peak temporal contrast sensitivity were reached earlier compared to the maturation of peak spatial contrast sensitivity. These data suggest that the mechanisms limiting the development of spatial and temporal contrast sensitivity mature at different rates and that there is a developmental change in shape of the TCSF.
Supported by a Fight for Sight grant to KAS and NIH grant EY-05864 to LK