Infants' sensitivity to motion and temporal change.

Infants from 1 month show a preference for moving over stationary stimuli (Volkmann and Dobson, J Exp Child Psychol 1976;22:86-99), but this does not demonstrate that they register motion as distinct from temporal change. We review behavioral and visual evoked potential results, which indicate that cortical processing of directional motion emerges around 7 weeks of age, with global motion processing emerging rapidly afterward. Motion and temporal properties seem to be sensitive indicators of neurodevelopmental disorders. Before motion processing develops, the infant's visual system is sensitive to the presence of rapid temporal change, but retinal and cortical processes are relatively poor at responding to temporally modulated spatial patterns. These results are discussed in terms of temporal imprecision in information transmission in the immature visual pathway and its impact on the development of infants' capabilities for analyzing visual motion.