Responses to a modified visual cliff by pre-walking infants born preterm and at term.

The purpose of this study was to examine, using a modified visual cliff apparatus, possible perceptual differences at crawling age between infants born preterm and infants born at term without documented visual or motor impairments. Sixteen infants born at term and 16 born preterm were encouraged to crawl to their caregivers on a modified visual cliff. Successful trials, crossing time, duration of visual attention, duration of tactile exploration, motor strategies, and avoidance behaviors were analyzed. A significant surface effect was found, with longer crossing times and longer durations of visual attention and tactile exploration in the condition with the visual appearance of a deep cliff. Although the two groups of infants did not differ on any of the timed measures, infants born at term demonstrated a larger number of motor strategies and avoidance behaviors by simple tally. This study indicates that infants born at term and those born preterm can perceive a visual cliff and adapt their responses accordingly.