Development of detection sensitivity to material properties in school-age children.

We examined children’s ability to discriminate between different object materials—such as low vs. high gloss, glossy vs. painted, gold vs. yellow plastic, and glass vs. silver—using images created with physically based computer graphics. Participants included children aged 6 to 12, divided into two age groups (younger group: 6 to 9.5 years old; older group: 9.5 to 12 years old), as well as adults. They were asked to select the one image out of four that looked different from the others. The results showed that the ability to discriminate gloss intensity develops from early to late childhood, whereas the ability to distinguish between gloss and white paint continues to develop beyond childhood. Furthermore, the findings suggest that the ability to distinguish gold from yellow plastic and silver from glass is already well developed during childhood. These findings suggest that discrimination of material category and gloss intensity emerges relatively early in development, while integration of specular properties and underlying 3D structures develops more gradually and with substantial individual variation.