ABSTRACT
This chapter examines the development of the smooth pursuit eye movement system in 1- to 4-month-old infants. The pioneering work of Westheimer illustrated that the smooth pursuit system is capable of accurately matching the velocity of a small moving target. In contrast to the saccadic system, the pursuit system appears to continuously update the estimated velocity of the moving target and program an appropriate acceleration or deceleration of the eye. Thus, target movements that contain changes in velocity are also responded to quite accurately. A quantitative characterization of the pursuit system consists of specifying three functions: the amplitude gain, the velocity gain, and the phase lag. In 1975 Aslin and Salapatek reported the results of a study on the saccadic system in 1- and 2-month-old infants who were presented with small targets at various retinal eccentricities. Their results, based on electro-oculography recordings, provided three new pieces of data on the infant's saccadic system.
