Age-related change and stability of individual differences in infant saccade reaction time

Abstract

Several facets of continuity in infant information processing were studied longitudinally using the visual expectation paradigm in a sample of 24 infants. At both 4 and 6 months of age, infants viewed an identical left-right alternating sequence of pictures while their eye movements were recorded. Human observers coded the videotape records to document saccadic reaction times (RT), rates of anticipatory fixation shifts to future pictures, and off-task behaviors. Measures of RT were reliable within each assessment and showed strong stability of individual differences across sessions. Measures of anticipation and off-task behaviors revealed few age differences, some within-session reliability, but no stability across sessions. Results provide strong evidence for continuity in some component of infant information processing during the early months of life.