Effects of normal and abnormal visual experience on the development of opposing aftereffects for upright and inverted...

We used opposing figural aftereffects to investigate whether there are at least partially separable representations of upright and inverted faces in patients who missed early visual experience because of bilateral congenital cataracts (mean age at test 19.5 years). Visually normal adults and 10-year-olds were tested for comparison. Adults showed the expected opposing aftereffects for upright and inverted faces. Ten-year-olds showed an adultlike aftereffect for upright faces but, unlike the adult group, no aftereffect for inverted faces. Patients failed to show an aftereffect for either upright or inverted faces. Overall, the results suggest that early visual input is necessary for the later development of (at least partially) separable representations of upright and inverted faces, a developmental process that takes many years to reach an adult-like refinement.