title: Young infants reach correctly in A-not-B tasks: on the development of stability and perseveration.
abstract: This paper examines the development of perseverative reaching in the A-not-B task. We describe two recent models that view perseveration as a sign of developmental progress toward stability. In Experiment 1, we test the novel prediction from both models that very young infants should not perseverate in the A-not-B task whereas older infants should. We tracked infants' behavior monthly on the A-not-B task and found that infants reached correctly at 5 months, and only perseverated at 7 and 8 months of age. Experiment 2 provides further evidence on the role of motor development in the emergence of perseveration by exploring the connection between perseveration and detailed changes in reach kinematics in two infants across the first year. These data together suggest that perseveration is a sign of developmental achievement on the path to stable and flexible behavior.
authors.affiliation: Whitman College, Department of Psychology, 345 Boyer Ave, Walla Walla, WA 99362, United States. clearfmw@whitman.edu
authors.forename: Melissa W
authors.initials: MW
authors.lastname: Clearfield
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Diedrich
authors.forename: Linda B
authors.initials: LB
authors.lastname: Smith
authors.forename: Esther
authors.initials: E
authors.lastname: Thelen
mesh_terms: D000367:Age Factors; D001132:Arm / Q000502:physiology; D002657:Child Development / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000502:physiology* / Q000523:psychology; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*