The effect of sucking on infants' orienting toward peripheral visual stimuli

We used static perimetry to measure the monocular visual fields of 32 one-month-olds and 32 two-month-olds, each of whom was tested during one session with a pacifier and one session without. Although sucking increased the latency of eye movements, it did not constrict the measured extent of the field. There was some suggestion that infants' eye movements were related more systematically to the visual stimuli during the session with the pacifier. We discuss implications for other measures and for understanding interactions among infants' behaviors.