Charting the boundaries of infant working memory

Visual working memory (WM), used for holding small amounts of information over brief intervals of time, undergoes rapid development in the second half of the first year of life. The research presented in this dissertation examines the nature of this development by testing the limits of infants’ WM in three different age groups, 6-month-olds, 9-month-olds, and 12-month- olds. A violation-of-expectation looking time method was used, in which sets of objects were hidden in multiple locations, and the contents of one of the locations was revealed to have changed, stayed the same, or disappeared completely. Both the number of locations, the number of objects, and the relevance of each object to the task were manipulated. The results show that infants’ WM can be characterized as limited, but flexible. Even in the face of severe limitations on what they can recall, 6-month-olds retain an inkling of an object. By 9 months, infants’ WM for what went where has improved, but breaks down when they have to keep track of more than two locations. By 12-months infants are better still, approaching adult-like levels of performance. Further, what infants recall depends on the relevance of the objects to a social agent. Implications for the structure and development of object WM are discussed.Ph. D.Includes bibliographical referencesby Melissa M. Kibb