Lisa Gershkoff-Stowe

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.

A Curvilinear Trend in Naming Errors as a Function of Early Vocabulary Growth.

This research examines changes in word retrieval and naming during a developmental period in which there is a substantial increase in productive vocabulary. That increase generally occurs when children have between 50 to 150 words in productive vocabulary. We examined childrens naming errors in two studies for what these errors could tell us about the emerging lexicon. The method we used for eliciting spontaneous naming was picture book reading by the parent. In Experiment 1, 12 children were followed longitudinally at three-week intervals from 15 to 22 months. Parent diaries were used as a measure of vocabulary growth. Experiment 2 used a cross-sectional design to compare the naming errors of 60 children assigned to one of three vocabulary ranges. Measures of vocabulary size were based on the MacArthur Communicative Development Inventory. In both experiments we found a sharp increase in naming errors in the picture book task that was coincident with sudden changes in productive vocabulary. These naming errors were often perseverative in nature and appear to reflect interference in the retrieval process from previously retrieved words. The results suggest that these errors in naming are a consequence of changes in lexical processing that occur with rapid growth of productive vocabulary and concurrent increased rates of speaking.

U-shaped changes in behavior: A dynamic systems perspective.

The traditional view of development is stage-like progress toward increasing complexity of form. However, the literature cites many examples in which children do worse before they do better. A major challenge for developmental theory, therefore, is to explain both global progress and apparent regression. In this article, we situate U-shaped development as a special case of the nonlinearity that is characteristic of all developmental process. We use dynamic systems theory to show how behavioral regression can be understood as part of the ordinary mechanisms of change. Examples from our work in infant motor and language development illustrate the ways that U-shaped behavior arises from continuous changes in the collective dynamics of multiple, contingent processes. A central claim is that true regression is not possible because behavior exists continuously in time. Thus the current state of the system always depends on its past history. Instead, the appearance of regression reflects the concept of softly assembled behavior, or the ability of contributing components to self-organize in different configurations that depend upon the status of the components, the environment, and the task.

Young Children's Discovery of Spatial Classification.

Abstract Around the age of 18 months, children begin to classify objects spatially by kind, placing objects of the same kind close together in space and placing unlike objects apart. This behavior may be symbolic in the sense that children use spatial proximity to represent similarity. We examined the possibility that spatial classification is discovered during play—that the external products of play lead children to use space to represent similarity. Experiment 1 was a longitudinal study of four childrens classification behaviors, observed from the age of 16 to 21 months. Results suggest that play with one kind of object to the exclusion of another kind leads to the discovery of spatial classification. Experiment 2 examined how childrens tendencies to interact with one category might promote spatial classification of multiple categories. Twenty-four 18-month-old children who did not yet spatially classify objects by kind participated. Children who were given the experience of playing with two kinds of objects in a context that promoted interaction with only one kind were more likely to demonstrate spontaneous spatial classification of multiple kinds in a subsequent test period. Children who played equally with both kinds did not show heightened spontaneous classification. The results further suggest that comparison of different kinds during play is critical to the spontaneous occurrence of spatial classification.

The Course of Children's Naming Errors in Early Word Learning

Young children sometimes use 1 word in the place of another when attempting to name an object. Previous research has suggested several reasons why children may call an object by another name, including faulty hypothesis testing concerning the meaning of words, limitations in vocabulary size, and difficulties in retrieving the desired word from lexical memory. This study examined childrens object naming in a longitudinal design. Ten children were tested at regular intervals from 16 to 24 months of age. Two tasks were presented: a picture book task used to elicit naming errors of known objects and a novel object task used to elicit word extensions to unknown referents. The results indicate that children are particularly prone to substitute 1 word for another during a narrow band of time, when they have between 50 and 150 words in their productive vocabularies. Moreover, the specific nature of the word substitutions suggests that they derive from common processes involving the activation and retrieval of words from a rapidly forming but still fragile lexicon.

Children and Adults Learn Actions for Objects More Readily Than Labels

Researchers tend to investigate word learning and action learning as separate and independent developments. Recently, however, a growing body of evidence suggests that underlying both labels and actions are parallel processes tightly coordinated with perceptual and motor functions. The present research addresses the nature of this developmental relation in the context of learning about objects. In three studies, children and adults were trained to map novel names and arbitrary actions to a set of unfamiliar objects. Receptive and productive knowledge were assessed. Two main findings emerged. First, participants of all ages learned actions more readily than labels. Second, the relationship between understanding and producing varied as a function of condition. The results suggest that actions are more accessible in memory than labels. Findings are interpreted within an embodied cognition framework according to which sensorimotor states form the basis of object concepts throughout development.

Priming overgeneralizations in two- and four-year-old children

Overgeneralization occurs when a child uses the wrong word to name an object and is often observed in the early stages of word learning. We develop a method to elicit overgeneralizations in the laboratory by priming children to say the names of objects perceptually similar to known and unknown target objects. Experiment 1 examined 18 two-year-old childrens labelling of familiar and unfamiliar objects, using a name that was previously produced. Experiment 2 compared the labelling of 30 two-year-olds and 39 four-year-olds when presented with completely novel objects. The findings suggest that the retrieved word is a blend of previous activation from the prior retrieval and activation engendered by the similarity of the test object to instances of the target category. We put forward a theoretical account of overgeneralization based on current models of adult language processing. The account suggests a common mechanism of activation and retrieval, which may explain not only momentary lapses in the correct selection of words, but other types of naming errors traditionally thought to reflect differences in childrens underlying category representations or, perhaps, gaps in their knowledge of words.