Barbara Landau

The importance of shape in early lexical learning

Abstract We ask if certain dimensions of perceptual similarity are weighted more heavily than others in determining word extension. The specific dimensions examined were shape, size, and texture. In four experiments, subjects were asked either to extend a novel count noun to new instances or, in a nonword classification task, to put together objects that go together. The subjects were 2-year-olds, 3-year-olds, and adults. The results of all four experiments indicate that 2- and 3-year-olds and adults all weight shape more heavily than they do size or texture. This observed emphasis on shape, however, depends on the age of the subject and the task. First, there is a developmental trend. The shape bias increases in strength and generality from 2 to 3 years of age and more markedly from early childhood to adulthood. Second, in young children, the shape bias is much stronger in word extension than in nonword classification tasks. These results suggest that the development of the shape bias originates in language learning—it reflects a fact about language—and does not stem from general perceptual processes.

“What” and “where” in spatial language and spatial cognition

Fundamental to spatial knowledge in all species are the representations underlying object recognition, object search, and navigation through space. But what sets humans apart from other species is our ability to express spatial experience through language. This target article explores the language of objects and places , asking what geometric properties are preserved in the representations underlying object nouns and spatial prepositions in English. Evidence from these two aspects of language suggests there are significant differences in the geometric richness with which objects and places are encoded. When an object is named (i.e., with count nouns), detailed geometric properties – principally the objects shape (axes, solid and hollow volumes, surfaces, and parts) – are represented. In contrast, when an object plays the role of either “figure” (located object) or “ground” (reference object) in a locational expression, only very coarse geometric object properties are represented, primarily the main axes. In addition, the spatial functions encoded by spatial prepositions tend to be nonmetric and relatively coarse, for example, “containment,” “contact,” “relative distance,” and “relative direction.” These properties are representative of other languages as well. The striking differences in the way language encodes objects versus places lead us to suggest two explanations: First, there is a tendency for languages to level out geometric detail from both object and place representations. Second, a nonlinguistic disparity between the representations of “what” and “where” underlies how language represents objects and places. The language of objects and places converges with and enriches our understanding of corresponding spatial representations.

Object name Learning Provides On-the-Job Training for Attention

By the age of 3, children easily learn to name new objects, extending new names for unfamiliar objects by similarity in shape. Two experiments tested the proposal that experience in learning object names tunes childrens attention to the properties relevant for naming—in the present case, to the property of shape—and thus facilitates the learning of more object names. In Experiment 1, a 9-week longitudinal study, 17-month-old children who repeatedly played with and heard names for members of unfamiliar object categories well organized by shape formed the generalization that only objects with similar shapes have the same name. Trained children also showed a dramatic increase in acquisition of new object names outside of the laboratory during the course of the study. Experiment 2 replicated these findings and showed that they depended on childrens learning both a coherent category structure and object names. Thus, children who learn specific names for specific things in categories with a common organizing property—in this case, shape—also learn to attend to just the right property—in this case, shape—for learning more object names.

Count Nouns, Adjectives, and Perceptual Properties in Children's Novel Word Interpretations

Three-year-old children were shown a novel exemplar toy and asked to judge test items that differed from the exemplar in shape, coloration, or material substance. In the count noun condition, children judged whether test items had the same novel name as the exemplar. In the adjective condition, children judged whether a test hern could be described by the same novel adjective as the exemplar. The results of 3 experiments indicated that children systematically attend to shape in interpreting novel count nouns, but their interpretation of adjectives is contextually determined. By the age of 6, children have acquired roughly 14,000 words (Templin, 1957). How do they acquire so many words so fast? If one views the childs acquisition of word-referent relations as an instance of unbiased hypothesis testing, then the rate of early word acquisition is difficult to explain. As Quine (1960) pointed out, the use of a word in the context of some scene provides evidence consistent with many hypotheses, only one of which will usually be correct. Chomsky (1986) similarly argued that if language learners were free to form any possible hypotheses about intended meaning from spoken language, then it would be unlikely that they would learn language as rapidly as they do because it would be unlikely that they would test the correct hypotheses early in language learning by happenstance alone. Chomsky argued that the rapid and error-free language learning that we observe in children requires that children be biased to entertain some hypotheses more than others. This idea has motivated much research on childrens early word learning. Developmentalists have shown that childrens novel word extensions are constrained or biased in certain directions. For example, young children appear biased to interpret count nouns as referring to object categories and not individual objects (Katz, Baker, & MacNamara, 1974) or thematic relations between objects (Markman & Hutchinson, 1984; Waxman & Kosowski, 1990). Children are biased to allow only one label for a single referent (mutual exclusivity, e.g., Markman, 1989; Markman & Wachtel, 1988), and they are biased to attend to shape when extending a novel count noun across novel objects (Landau, Smith, & Jones, 1988). The existence of these biases is sometimes cited as an explanation of rapid word growth; the idea is that word learning proceeds as fast as it does precisely because word learning biases exist.

Spatial knowledge in a young blind child

Abstract A set of eight experiments demonstrate spatial knowledge in a 2-year-old congenitally blind child and sighted blindfolded controls. Once the blind child had traveled along specific paths between objects in a novel array, she was able to make spatial inferences, finding new routes between those objects (Experiment 1). She could also do so when the routes were between places in space, not occupied by objects (Experiment II). Deviations from precisely straight routes in Experiments I and II were not due to faulty inferences, but probably came from imprecise motor control, since the same deviations occured when inferences were not required—when the child moved to a place designated by a sound source (Experiment III). This childs performances could not be accounted for by artifactual explanations: sound cues, experimenter bias, and echolocation were ruled out (Experiments IV, V, VI). Further, sighted blindfolded controls performed at roughly the same level (Experiment VII). Finally, Experiment VIII shows that the blind child could access her spatial knowledge for use in a simple map-reading task. We conclude that the young blind child has a system of spatial knowledge, including abstract, amodal rules

Syntactic context and the shape bias in children's and adults' lexical learning

Abstract Previous research has shown that young children and adults share a shape bias in learning novel object count nouns: they generalize the label to objects sharing the same shape as a standard but differing greatly in size or texture (Landau, Smith, & Jones, 1988) . Three experiments tested the hypothesis that this shape bias is linked specifically to the acquisition of count nouns and therefore should be altered systematically by manipulating the form class of the novel word. Three-year-olds, five-year-olds, and adults were shown an object and taught a novel word in one of several different syntactic contexts and were asked to generalize the word to objects varying from the standard in shape, size, or texture. In the count noun context, “This is a dax,” all subjects showed the original shape bias even when the standard objects texture was made extremely salient. In the superordinate context, “This is a kind of dax,” 5-year-olds and adults showed a weaker shape bias, broadening their acceptance of shape changes. In the adjective context, “This is a daxy one” 5-year-olds and adults narrowed their acceptance of texture changes and broadened acceptance of shape changes, as did 5-year-olds in another adjective context, “This is a dax one.” Three-year-olds showed similar patterns of differentiation over the kind of and adjective contexts, but in a much weaker form. The results are discussed in terms of the representation of objects and their properties, the syntactic representation of these, and the joint interaction of syntax and perception in the early acquisition of words describing objects.

Will the real grandmother please stand up? The psychological reality of dual meaning representations

Two types of meaning representation are described, symptom and criterion, and it is argued that both have psychological status in mental representations of kinship terms. Certain symptoms, such as old age and biofocals for grandmothers, are likely indicators of grandmotherhood, but they do not reliably pick out all positive instances, nor do they indicate negative ones. Criteria specify the necessary and sufficient conditions for grandmotherhood: having a grandchild. The psychological reality of these two representations was demonstrated by asking children and adults to select kin-term exemplars from pictures in which both age and reciprocal kin symptoms are displayed, and to justify their selections. In both tasks, there was change with age away from using typical age as the sole basis for performance; older subjects selected pictures displaying reciprocal kin, and justified their choices by referring to the criterion. More important, at each age level, there was evidence for dual representation: Even subjects who selected pictures based on the age symptom often gave criterial justifications, and subjects who selected pictures based on the reciprocal kin symptom still preferred pictures displaying age symptoms in addition to the reciprocal kin.

Early map use as an unlearned ability

Abstract Four experiments demonstrated that certain fundamental principles of map use can be accessed without any specific training. Results showed that a 4-year-old congenitally blind child with no previous map-use experience could use a 2-symbol map to directionally guide her locomotion in space, with successful location of objects in front of her, behind her, to her left, or to her right. She could do so under conditions where the map and space were aligned in front of her (canonical condition), and under various transformation conditions: sideways translation, front-behind translation, and vertical rotation. In these conditions, there was no straightforward spatial relationship between her position in space, and her represented position on the map; therefore, mental alignments of the map with external space were necessary. Control data from sighted children showed that, by 4 years, they too could interpret and use these maps. Analysis of the requirements of this simple map task suggests that a core of the knowledge required to use maps is a readily accessible product of a spatial knowledge system common to both the blind and sighted.

Spatial breakdown in spatial construction: Evidence from eye fixations in children with Williams syndrome

We investigated the role of executive and spatial representational processes in impaired performance of block construction tasks by children with Williams syndrome (WS), a rare genetic defect that results in severely impaired spatial cognition. In Experiment 1, we examined performance in two kinds of block construction tasks, Simple Puzzles, in which block faces contained a single color, and Complex, in which some block faces contained an arrangement of two colors. WS and control children were comparable in their ability to solve simple puzzles, and showed similar eye-fixation patterns, suggesting that basic executive processes were intact. However, WS children were severely impaired in their ability to solve complex puzzles. In these puzzles, WS children fixated the complex puzzle models and checked their partial solutions less often than normal children, but they were comparable in their ability to detect errors in their copies and almost exclusively made repairs to copies that were, in fact, incorrect. We conjecture that the abnormal fixation patterns were a consequence of impoverished spatial representations, rather than a cause of it. This conjecture was tested in Experiment 2, where we examined childrens capacity to match and place individual blocks without engaging the complex executive processes required to carry out a complete puzzle solution. We found serious deficiency among WS children in both aspects of spatial representation. Moreover, estimates of the errors in representing the identity and location of model blocks derived from Experiment 2 provided a good account of the observed errors in the block construction task of Experiment 1.

Intact Perception of Biological Motion in the Face of Profound Spatial Deficits: Williams Syndrome

Williams syndrome (WS) is a rare genetic disorder that results in profound spatial cognitive deficits. We examined whether individuals with WS have intact perception of biological motion, which requires global spatial integration of local motion signals into a unitary percept of a human form. Children with WS, normal mental-age-matched children, and normal adults viewed point-light-walker (PLW) displays portraying a human figure walking to the left or right. Children with WS were as good as or better than control children in their ability to judge the walkers direction, even when it was masked with dynamic noise that mimicked the local motion of the PLW lights. These results show that mechanisms underlying the perception of at least some kinds of biological motion are unimpaired in children with WS. They provide the first evidence of selective sparing of a specialized spatial system in individuals with a known genetic impairment.