Abstract
The development of the Contrast Sensitivity Function (CSF) has been studied many times, but there is no consensus yet as to when sensitivity for different spatial frequencies (SFs) becomes mature. Many methods have been used, many different ranges of SFs have been measured, different age groups have been studied, and results differ greatly between studies. Here, we used an objective psychophysical method to measure the CSF across seven SFs (0.5 to 30 cpd), in 124 individuals between 5 and 28 years of age. All participants viewed Gabor patches on a calibrated computer monitor and completed an orientation discrimination task (vertical vs. horizontal). Distance was kept constant using a chin rest. The FWHM of the Gaussian envelop was 2 degrees of visual angle. Noise-bit dithering (Allard & Faubert, 2008) was applied to every stimulus. Contrast was adjusted across trials (48 trials per SF) independently for each SF, using QUEST (Watson & Pelli, 1982), to reach a target accuracy of 65%. The mean contrast threshold obtained at the end of the QUEST run was used to determine sensitivity for each SF. For all SFs, sensitivity correlated significantly and positively with age (minimal r=.24; all p's< .05). Next, to determine at what age sensitivity becomes adult-like, we fitted the function If x< c, y = a*x+b; else, y = a*c+b; The parameter c corresponds to the age at which sensitivity stops improving. We found that sensitivity matures around 12-13 years of age, and slightly earlier for low SF than high SF. This result is compatible with past results on the development of low-level vision and what we know about brain maturation.
Meeting abstract presented at VSS 2018