Newborns' perception of left-right spatial relations.

Five experiments examined 79 newborns' ability to discriminate and categorize a spatial relation, defined by the left-right spatial position of a blinking object-target with respect to a vertical landmark-bar. Three-day-old infants discriminated the up versus low position of an object located on the same side of the landmark-bar (Experiment 1) and recognized a basic left-right spatial invariance of the object-target and the landmark-bar in conditions of low (Experiment 2) and high (Experiment 3) perceptual variability of the object's positions. Additional evidence ruled out the possibility that newborns were unable to discriminate the within-category left-right spatial positions of the object-target (Experiment 4) or made a categorical distinction based on spatial distance rather than on categorical spatial relations of left of and right of (Experiment 5).