Development of postrotatory nystagmus time constants

Infant eye movements: quantification of the vestibulo-ocular reflex and visual-vestibular interactions

The gain of the infant vestibulo-ocular reflex (VOR) was determined when infants were rotated either in total darkness or while they viewed visual targets consisting of a stationary spot or a full field of black and white stripes. The average VOR gain in the dark was 1.03 +/- 0.014 for 1-4-month-old infants and 0.59 +/- 0.03 for adult subjects tested with appropriate controls for psychological "set". Longitudinal studies showed no significant change in gain over the first 4 months of life. Although the presence of the spot or full-field striped background increased adult compensatory gains from 0.59 to 1.0, the same visual targets had no effect on infant gains. Thus, an infant's VOR gain of nearly 1.0 apparently reduces reliance on the poorly developed smooth pursuit and optokinetic systems that, in adults, help the VOR provide perfect ocular stabilization.

Development of conjugate human eye movements

Early studies of the development of oculomotor control in human infants relied on descriptions of eye movements. Recently, studies have been carried out using eye movement recording techniques typically used with adults. This review first considers the limitations of such techniques, especially as they are used with human infants, and then discusses the results of recent studies of human oculomotor development.