How do infants acquire the fundamental cognitive ability to mentally represent an object after it has disappeared from sight (i.e., the object concept)? The aim of this research is to test predictions from a constructivist account of object concept development proposing that infants' mental representations of objects are constructed with experience, increase gradually in strength across development, and are stronger in some contexts than others. This representation-strength constructivist account is contrasted with a core-knowledge account proposing that infants have innate knowledge in several core domains, including the domain of objects. In terms of scientific benefits, the work has important implications for these contrasting theories about the extent to which human knowledge in core domains (e.g., object knowledge) is constructed versus innate. Such theories yield different implications for the initial state of the human mind, what changes with development, how developmental changes occur, and what experiences may or may not be necessary to optimize developmental outcomes. In terms of societal benefits, this work has the potential to inform the public, particularly parents, child-care providers, and others with a vested interest in child development outcomes, about the nature and development of fundamental cognitive abilities in infancy.
Two projects will test predictions from a representational-strength constructivist approach about how representation strength for objects changes with development and, consequently, how it affects infants' performance on object concept tasks. The first project tests competing explanations for why infants search for objects hidden by darkness several months earlier than they search for objects hidden in the light with a cover. A representation-strength constructivist view uniquely suggests that visible covers interfere more than darkness does with infants' relatively weak mental representations of hidden objects. In contrast, innate or core knowledge perspectives have suggested the discrepancy reflects a competence-performance problem: Infants cannot demonstrate their knowledge competence in tasks with covers because of secondary performance problems such as deficits in motor-planning or problem-solving skills. The first project tests competing predictions from these two accounts in three experiments with 6- to 10-month-old infants. The second project tests predictions from a representation-strength view about what specific variables become incorporated into infants' mental representations of objects, ultimately making them stronger and more resistant to interference. These factors range from perceptual support of representations in the form of auditory cues, to the extent of infants' familiarity with the object through experience, to conceptual support through infants' knowledge in other domains, such as category knowledge and linguistic knowledge. These predictions will be tested in six experiments with 7- to 10-month-old infants. These two projects will inform both constructivist and core knowledge perspectives by contributing to scientific understanding of how mental representations of objects change across development during infancy.
