Abstract
Accumulating evidence suggests that the adult visual system is optimally tuned for processing the spatial properties of natural scenes (1/fαamplitude spectra). It is also documented that different aspects of spatial vision (e.g., acuity and spatial contrast sensitivity) develop at different rates and some do not become mature until late childhood. We compared natural scene perception in children aged 6, 8, and 10 years (n = 16 per age) and in adults (mean age = 23). A same-different task combined with a staircase procedure measured thresholds for discriminating change in the slope of the amplitude spectra of natural scene stimuli with reference α's of 0.7, 1.0, or 1.3. First, consistent with previous studies, adults were least sensitive for the shallowest α (i.e., 0.7) and most sensitive for the steepest α (i.e., 1.3). Second, a 4 (age group) X 3 (reference α's) repeated measures ANOVA revealed a significant interaction (p [[lt]] 0.01). Post-hoc analyses of the interaction indicated no difference in threshold among any of the age groups for the α of 0.7. However, the 6- and 8-year-olds had significantly higher discrimination thresholds compared to the 10-year-olds and adults for α's of 1.0 and 1.3. Finally, the 10-year-olds' thresholds did not differ significantly from those of adults for any of the α's tested. These data suggest that sensitivity for detecting change in the spatial characteristics of natural scenes during childhood may not be optimally tuned to the statistics of natural images until about 10 years of age.
Supported by an NSERC grant to D.E.