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Lab Personnel > Dr. Hilary Leevers |
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Biographical Sketch | Publications | Abstracts |
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Selected Abstracts
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Harris, P. L. & Leevers, H. J. (2000). Pretending, imagery and self-awareness in autism. In S. Baron-Cohen., H. Tagler-Flusberg, & D. Cohen, D. J. (Eds.) Understanding Other Minds: Perspectives from Autism and Cognitive Neuroscience (2nd ed.), pp182-202. Oxford University Press, UK. |
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Abstract. In this chapter, we examine the idea that children with autism suffer from an impoverished imagination and lack awareness of their own mental states. Our starting point is the deficit in pretend play that Kanner included in his original description of the syndrome (Kanner, 1943). We review evidence showing that although children with autism can engage in pretence and appear to understand its special logic, they do play in a restricted or stereotypic fashion. We then consider recent, longitudinal studies that have focused on the development of pretend play in the second year of life. When pretend play has not emerged by 18 months, and is combined with social difficulties, notably problems in establishing joint attention, a subsequent diagnosis of autism is likely. However, evidence from older children shows that the problem with pretend play is not just a by-product of the social difficulties of children with autism. It is part of a deficit in generating or executing ideas. We go on to ask whether that deficit reflects: (i) a specific problem with ideas that involve the unreal or the impossible or (ii) a more widespread problem of generating or executing even relatively prosaic ideas. We argue that children with autism are handicapped, not in dealing with unreal images but in dealing with novelty, especially when they must compose a sequence of actions with little guidance from the external environment or from previous habits. We then examine recent first person reports by adults with autistic symptoms in order to gain further clues into their inner life. We speculate that individuals with autism may experience a mental life that is primarily visual rather than verbal, and may therefore be helped to acknowledge that mental life if they are provided with pictorial rather than verbal indices. We consider the implications of this speculation for the development and education of children with autism. |
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Harris, P. L. & Leevers, H. J. (2000). Reasoning from false premises. In P. Mitchell & K. J. Riggs. (Eds.) Children's Reasoning and the Mind, 67-86. Psychology Press, Hove. |
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Abstract. In order to work out the implications of a given premise, it is often necessary to set aside doubts about its truth or likelihood. According to a long tradition of research, adults who have received little or no schooling find it difficult to set aside such doubts, and therefore often fail to grasp the implications of the premise as stated. Building on these findings, it has been proposed that the ability to adopt an "analytic mode"&endash;to set real-world considerations aside, and to reason from the premises as stated&endash;is not something that comes either naturally or early to human beings. Martin Braine formulated this conclusion as follows: "Artificially setting aside part of what you know is an academic game, and there is no reason to assume that our ancestors' life conditions would lead them to acquire much skill at that game" (Braine, 1990; p. 136). In this chapter, we argue for a different position. We contend that subjects with little or no formal education, including young children, can reason analytically, in the sense that they are good at temporarily setting aside their real-world knowledge and reasoning from premises that they know to be false. They are able to do this in the case of syllogistic reasoning, when drawing causal conclusions about what would have happened if the antecedent circumstances had been different, and when considering false beliefs or unfulfilled desires. In our view, education does not bring about any sea-change in the way that counterfactual premises are handled. Instead, it helps the reasoner to decide more accurately what stance toward the premises is appropriate for a given context. |
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Leevers, H. J. & Harris, P. L. (2000). Counterfactual syllogistic reasoning in normal four-year-olds, children with learning disabilities, and children with autism. Journal of Experimental Child Psychology, 76, 64-87. |
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Abstract. Instruction encouraging imagery improves logical reasoning with counterfactual premises by normal preschool children. By contrast, children with autism have been reported to reason accurately with counterfactual premises in the absence of such instruction (Scott, Baron-Cohen, & Leslie, 1999). To investigate this pattern of findings, we compared the performance of children with autism, children with learning disabilities, and normally developing 4-year-olds, who were given reasoning problems both with and without instruction in two separate testing sessions, two- to three-weeks apart. Overall, instruction to use imagery led to persistent logical performance. However, children with autism displayed a distinctive pattern of responding, performing around chance levels, showing a simple response-bias, and rarely justifying their responses by elaborating on the premises. We propose that instruction boosts logical performance by clarifying the experimenter's intention that a false proposition be accepted as a basis for reasoning and that children with autism have difficulty grasping this intention. |
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Leevers, H. J. & Harris, P. L. (1999). Persisting effects of instruction on young children's syllogistic reasoning with incongruent and abstract premises. Thinking and Reasoning, 2, 145-173. |
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Abstract. Studies of reasoning have often invoked a distinction between a natural or ordinary consideration of the premises, in which they are interpreted, and even distorted, in the light of empirical knowledge, and an analytic or logical consideration of the premises, in which they are analysed in a literal fashion for their logical implications. Two or three years of schooling have been seen as critical for the spontaneous use of analytic reasoning. In two experiments, however, 4-year-olds who were given brief instructions that prompted use of an analytic approach continued to adopt this approach one week later. Thus, when given syllogistic problems in which the major premise was incongruent with their empirical knowledge (e.g., "All snow is black"), instructed children reasoned more accurately from that premise both immediately and a week later as compared to children given only a basic introduction. A third experiment showed that instructions also improved 4-year-olds' performance on hard-to-imagine, abstract material (e.g., "All mib is white"). Similarities between the effects of brief instruction and of schooling are discussed. |
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Goswami, U., Leevers, H., Pressley, S., & Wheelwright, S. (1998). Causal reasoning about pairs of relations and analogical reasoning in young children. British Journal of Developmental Psychology, 16, 553-569. |
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Abstract. Two experiments were conducted to investigate how children aged 3-6 years performed in classical analogy problems based on single and double relations. The number of relations in an analogy is seen as an important competence factor in G. S. Halford's theory of analogical development (1987, 1992, 1993). In contrast, other authors have proposed that the critical factor in analogical success is relational familiarity (e.g., A. L. Brown, 1989; Z. Chen & M. W. Daehler, 1989; D. Gentner, 1989; U. Goswami, 1992, 1996; K. Inagaki & G. Hatano, 1987; S. Vosniadou, 1989). In these experiments, the authors gave children analogies to solve based on pairs of causal relations (such as cutting and wetting), and also measured their performance when similar analogies were based on single relations (such as cutting or wetting). The ability to process the relations or relation used in each analogy was also measured in control conditions. The results suggested that the number of relations in an analogy does not overload available capacity. Clear "learning-to-learn" effects were found in both studies, showing that children's analogical performance can improve significantly over the course of an experiment, even when relational familiarity is present. |
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Leevers, H. J. & Harris, P. L. (1998). Drawing impossible entities: A measure of the imagination in children with autism, children with learning disabilities, and normal four-year-olds. Journal of Child Psychology and Psychiatry, 39, 399-410. |
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Abstract. Tested whether children with autism display an inability to imagine impossible entities when the task demands are minimal. Ss were 3 groups of 4-yr-olds who were either normal, had moderate learning disabilities, or had been diagnosed with autism. Ss were individually tested and had to identify either the real or the impossible version of a picture from pairs of pictures (e.g., a yellow or blue banana). Ss also completed 4 pairs of drawings, by adding a pattern or color to them, to make one real and one impossible version in every pair. Results show that the Ss were equally successful at identifying real and impossible pictures and at completing pictures to make them look either real or impossible. There was no evidence that the children required corrective feedback in order to understand the terms (or the task); performance was accurate from the outset. Ss' drawings are appended. |
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Treiman, R., Goswami, U., Tincoff, R., & Leevers, H. (1997). Effects of dialect on American and British children's spelling. Child Development., 68, 229-245. |
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Abstract. Two experiments were carried out to compare the spelling of children (aged 6-8 yrs) who speak General American English vs Southern British English. The first dialect is rhotic (/r/ may occur after a vowel in a syllable), and the second is nonrhotic (/r/ may not occur in this context). Young children's spelling errors reflected the characteristics of their dialect. For example, American children with spelling ages of about 6-7.5 often misspelled hurt as "hrt" whereas British children of similar spelling levels were more likely to misspell it as "hut". Such errors were uncommon by spelling ages of greater than 7.5 yrs. Even at these spelling ages, however, the British children made overgeneralization errors that reflected their dialect. For example, they sometimes spelled bath as "barth" based on the fact that "bath" contains the same vowel sound as "card" in their dialect. The results show that phonology plays an important role in children's spelling development. |
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MacLaren, I. P. L., Leevers, H. J., & Mackintosh, N. J. (1994). Recognition, categorization, and perceptual learning (or, how learning to classify things together helps one to tell them apart). In C. Umiltà & M. Moscovitch, (Eds.) Attention and Performance XV, Conscious and Nonconscious Information Processing. MIT Press. |
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Abstract. (from the chapter) examine the role of perceptual learning in experiments on recognition and categorization by people and pigeons that satisfy some of these criteria / demonstrate an effect of perceptual learning in a recognition experiment involving stimuli drawn from categories not definable in terms of a prototype / show that perceptual learning will also occur during the course of categorization: asked to categorize a series of stimuli generated by allowing variations from 2 prototypical patterns, people (and perhaps pigeons) subsequently learn to discriminate faster between 2 novel examplars drawn from a single category than between 2 control stimuli drawn from a category that the S has not previously experienced ask to what extent the behavior of more articulate Ss (students at Cambridge University) resembles that of pigeons and is thus potentially explicable by . . . simple associative theory / report the results of 2 sets of experiments / in the 1st, Ss are engaged in a continuous recognition task / in the 2nd they are required to categorize a set of stimuli. |
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Dr. Hilary Leevers
Biographical
Sketch |
Publications
| Abstracts