title: General to specific development of movement patterns and memory for contingency between actions and events in young infants.
abstract: To understand infants' learning of the contingency between their actions and events, we studied inter-limb movement patterns of 48 infants aged 2-4 months when they attempted moving a mobile using a string attached to their arm. The session was composed of baseline, acquisition, immediate retention test, re-acquisition, interference, and delayed retention test periods. The analysis revealed motor pattern dependence on age--infants exhibited increased movement over base line of all limbs (2-month-olds), both arms (3-month-olds), and the connected arm (4-month-olds). The acquired patterns were produced during immediate and delayed test periods across age groups. The results suggest that 2-month-olds can acquire and retain general body movements that induce contingent changes in a mobile, while 3- and 4-month-olds form memories that serve as a constraint enabling highly specific movement of their arm to effectively activate the mobile.
authors.affiliation: Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi-shi, Saitama, Japan. hama@p.u-tokyo.ac.jp
authors.forename: Hama
authors.initials: H
authors.lastname: Watanabe
authors.forename: Gentaro
authors.initials: G
authors.lastname: Taga
mesh_terms: D000367:Age Factors; D001132:Arm / Q000502:physiology; D002657:Child Development / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D007866:Leg / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*