SPATIOTEMPORAL CONTINUITY, SMOOTHNESS OF MOTION AND OBJECT IDENTITY IN INFANCY

A preferential looking method served to investigate 4-month-old infant s' apprehension of the identity of objects over successive encounters. In Expts 1 and 2, infants were familiarized with events in which obje cts moved either continuously or discontinuously behind two narrow scr eens. Subsequent looking times to one- vs. two-object displays provide d evidence that infants apprehend object identity in accord with the p rinciple that objects move continuously. In Expts 3 and 4, infants wer e familiarized with events in which objects moved behind one wide scre en with an occlusion time either appropriate or inappropriate to their visible speed. Subsequent looking times to one- vs. two-object displa ys provided no evidence that infants apprehend object identity in acco rd with the principle that objects move smoothly. The findings are con trasted with those of studies of infants' search for objects. Continui ty may be an early-developing, core principle by which humans individu ate objects, but this principle may not guide all early-developing act ions on objects.