Object manipulation and exploration in 2- to 5-month-old infants.

The early development of explorarory behavior was studied. One study documents changes in free exploration of infants aged from 2 to 5 months. Another compares 3- and 4-5 month-olds when manipulating and exploring an object in the light or in the dark (no visual control over exploration). The third study compares multimodal exploration in 3- and 4-month-olds when presented with two different objects varying in multiple properties. Results show that significant changes occur between 2 and 5 months, relative to spontaneous multimodal exploration of a novel object. Object exploration becomes increasingly multimodal. Bimanual coordination is first linked to the oral system, later reorganized in reference to vision when fingering emerges by 4 months. Manipulation in 3-montholds is shown to be object-dependent. Factors controlling early object manipulation and functional changes in manual action prior to 6 months of age are discussed. When young infants are in an alert and quiet state, they display behaviors that are exploratory in nature because they appear to be primarily oriented toward bringing sense organs into various relations with objects in the environment. Newborns show elements of reaching with arms and hands toward an object moving close to them (Hofsten, 1982). Young infants track objects moving in their field of view with both eyes and head (Bullinger, 1984). From birth, they orient their heads in the direction of a sound source (Clifton, Morrongiello, Kulig, & Dowd, 1981; Muir & Field, 1979) and appear to selectively orient (root) their mouths in the direction of a familiar odor (Macfarlane, 1975). Contrary to the view that babies are passive spectators bombarded with stimulation, these observations indicate that from the earliest age infants are actors and, in particular, explorers of their environment. From a theoretical point of view, it is relevant to approach early behavior as involving action systems with specific adaptative functions like communi