Development of orienting to locations and objects in human infants.

Two experiments investigated preference for orienting to novel locations and novel objects in young infants. Adults and infants of six months and older show a propensity to orient to locations that have not recently been inspected (inhibition of return). Preference for novel locations undergoes development. We show that, similar to adults, its development is related to the ability to program eye movements to attended locations. This preference appears to emerge as infants gain the ability to program eye movements to target locations. Experiment 1 demonstrates that three-month-olds show inhibition of return for 10 degrees target eccentricities, but not for 30 degrees target eccentricities. In a second experiment, three- and six-month-old infants oriented to 10 degrees targets that varied in location and object identity. Infants of both ages strongly preferred orienting to novel objects at novel locations. At three months, the preference for novel objects was equal to the preference for novel locations, while at six months a tendency to prefer novel objects over novel locations emerged. Overall, the findings support separate development of these two forms of novelty preference, and suggest that novel location preferences (inhibition of return) relates closely to the eye movement system. The findings are discussed in relation to issues concerning development, physiology, and cognition.