Spatial resolution of conscious visual perception in infants.

Humans' conscious awareness of objects in their visual periphery is limited. This limit is not entirely the result of reduced visual acuity. Rather, it is primarily caused by crowding--the difficulty identifying an object when it is surrounded by clutter. The effect of crowding on visual awareness in infants has yet to be explored. Do infants, for example, have a fine-grained "spotlight," as adults do, or do infants have a diffuse "lantern" that sets limits on what they can register in their visual periphery? We designed an eye-tracking paradigm to psychophysically measure crowding in infants between 6 months and 15 months of age. We showed infants pairs of faces at three eccentricities, in the presence or absence of flankers, and recorded infants' first saccade from central fixation to either face. Infants could discriminate faces in the periphery, and flankers impaired this ability. We found that the effective spatial resolution of infants' visual perception increased with age, but was only half that of adults.