Margaret Anne Defeyter

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In the candle problem (Duncker, 1945), subjects must attach a candle to a vertical surface, using only a box of tacks and a book of matches. Subjects exhibit functional fixedness by failing, or being slow, to make use of one object (the tack box) as a support, rather than as a container, in their solutions. This failure to produce alternate functions is(More)
There is a change in false belief task performance across the 3-5 year age range, as confirmed in a recent meta-analysis [Wellman, H. M., Cross, D., & Watson, J. (2001). Meta-analysis of theory mind development: The truth about false-belief. Child Development, 72, 655-684]. This meta-analysis identified several performance factors influencing success,(More)
This study investigated whether the glycaemic index (GI) of breakfast cereal differentially affects children's attention and memory. Using a balanced cross-over design, on two consecutive mornings 64 children aged 6-11 years were given a high GI cereal and a low GI cereal in a counterbalanced order. They performed a series of computerised tests of attention(More)
The human ability to make tools and use them to solve problems may not be zoologically unique, but it is certainly extraordinary. Yet little is known about the conceptual machinery that makes humans so competent at making and using tools. Do adults and children have concepts specialized for understanding human-made artifacts? If so, are these concepts(More)
Adequate levels of vitamins and minerals are essential for optimal neural functioning. A high proportion of individuals, including children, suffer from deficiencies in one or more vitamins or minerals. This study investigated whether daily supplementation with vitamins/minerals could modulate cognitive performance and mood in healthy children. In this(More)
In this chapter, we have considered the nature and development of our capacities for the representation of artificial kinds. We have presented a range of evidence collected using varying methods and from our own laboratories and those of others that speaks to the question of the kinds of information that might be central to knowledge of artifacts and their(More)
Research suggests that while information about design is a central feature of older children's artifact representations it may be less important in the artifact representations of younger children. Three experiments explore the pattern of responses that 5- and 7-year-old children generate when asked to produce multiple uses for familiar (Experiments 1, 2)(More)
Appropriate behavior in relation to an object often requires judging whether it is owned and, if so, by whom. The authors propose accounts of how people make these judgments. Our central claim is that both judgments often involve making inferences about object history. In judging whether objects are owned, people may assume that artifacts (e.g., chairs) are(More)
Two studies investigated the relative importance of information about intended design and current use on judgments about the function (Experiment 1) or category (Experiment 2) of novel artifacts in preschool children and adults. Adults assigned function and name on the basis of information about design across all conditions, while children's decisions about(More)
It is impossible to perceive who owns an object; this must be inferred. One way that children make such inferences is through a first possession bias--when two agents each use an object, children judge the object belongs to the one who used it first. Two experiments show that this bias does not result from children directly inferring ownership from first(More)