Search

Previous studies of children's reorientation have focused on cue representation (e.g., whether cues are geometric) as a predictor of performance but have not addressed cue reliability (the regularity of the relation between a given cue and an outcome) as a predictor of performance. Here we address both factors within the same series of experiments. We show that for 18- to 30-month-olds, high cue reliability is a dominant factor positively affecting reorientation behavior. Under conditions of high cue reliability, children use both scalar and nonscalar cues for successful reorientation. By contrast, under conditions of low cue reliability, children successfully use scalar cues but not nonscalar cues, suggesting that mapping of left-right visual features onto a viewer-centric sense of left and right is facilitated when features themselves are ordered. More generally, we suggest that cue-driven spatial reorientation is best understood as part of a broader system capable of flexibly linking stimuli and responses.

When geometric and non-geometric information are both available for specifying location, men have been shown to rely more heavily on geometry compared to women. To shed insight on the nature and developmental origins of this sex difference, we examined how 18- to 24-month-olds represented the geometry of a surrounding (rectangular) space when direct non-geometric information (i.e. a beacon) was also available for localizing a hidden object. Children were tested on a disorientation task with multiple phases. Across experiments, boys relied more heavily than girls on geometry to guide localization, as indicated by their errors during the initial phase of the task, and by their search choices following transformations that left only geometry available, or that, under limited conditions, created a conflict between beacon and geometry. Analyses of search times suggested that girls, like boys, had encoded geometry, and testing in a square space ruled out explanations concerned with motivational and methodological variables. Taken together, the findings provide evidence for an early sex difference in the weighting of geometry. This sex difference, we suggest, reflects subtle variation in how boys and girls approach the problem of combining multiple sources of location information.

The present longitudinal study examines the role of caregiver speech in language development, especially syntactic development, using 47 parent-child pairs of diverse SES background from 14 to 46 months. We assess the diversity (variety) of words and syntactic structures produced by caregivers and children. We use lagged correlations to examine language growth and its relation to caregiver speech. Results show substantial individual differences among children, and indicate that diversity of earlier caregiver speech significantly predicts corresponding diversity in later child speech. For vocabulary, earlier child speech also predicts later caregiver speech, suggesting mutual influence. However, for syntax, earlier child speech does "not" significantly predict later caregiver speech, suggesting a causal flow from caregiver to child. Finally, demographic factors, notably SES, are related to language growth, and are, at least partially, mediated by differences in caregiver speech, showing the pervasive influence of caregiver speech on language growth. (Contains 6 figures and 9 tables.)

Prior studies indicate that children vary widely in their mathematical knowledge by the time they enter preschool and that this variation predicts levels of achievement in elementary school. In a longitudinal study of a diverse sample of 44 preschool children, we examined the extent to which their understanding of the cardinal meanings of the number words (e.g., knowing that the word "four" refers to sets with 4 items) is predicted by the "number talk" they hear from their primary caregiver in the early home environment. Results from 5 visits showed substantial variation in parents' number talk to children between the ages of 14 and 30 months. Moreover, this variation predicted children's knowledge of the cardinal meanings of number words at 46 months, even when socioeconomic status and other measures of parent and child talk were controlled. These findings suggest that encouraging parents to talk about number with their toddlers, and providing them with effective ways to do so, may positively impact children's school achievement. (Contains 2 footnotes, 4 tables, and 5 figures.)

The ability to locate objects in the environment is adaptively important for mobile organisms. Research on location coding reveals that even toddlers have considerable spatial skill. Important information has been obtained using a disorientation task in which children watch a target object being hidden and are then blindfolded and rotated so they cannot track their changing relation to the target. Even toddlers under two years of age search successfully for the hidden object, which shows that they can use geometric features of the spatial environment to determine object location. It has been claimed that these results show innate geometric abilities, but there is evidence that these early spatial skills are not simply geometric. The article presents an overview of experimental findings that provide the basis for a different interpretation of spatial development.

Both animals and human toddlers can find an object in a rectangular enclosure after they have been disoriented. They use geometric cues (relative lengths of walls) to discriminate among different corners (e.g. long wall to the left, short to the right). It has been claimed that this ability is "modular", i.e. exclusively geometric. The present study demonstrates that the ability toddlers exhibit is a more general one, namely, an ability to discriminate relative quantity. Using a square enclosure, we show that toddlers use the relative sizes of the figures on different walls to characterize different corners. We also show that they do not use simple non-relative features to distinguish different corners. Possible reasons for differences in the ability to use relative versus non-relative cues are discussed.

This article examines caregiver speech to young children. The authors obtained several measures of the speech used to children during early language development (14-30 months). For all measures, they found substantial variation across individuals and subgroups. Speech patterns vary with caregiver education, and the differences are maintained over time. While there are distinct levels of complexity for different caregivers, there is a common pattern of increase across age within the range that characterizes each educational group. Thus, caregiver speech exhibits both long-standing patterns of linguistic behavior and adjustment for the interlocutor. This information about the variability of speech by individual caregivers provides a framework for systematic study of the role of input in language acquisition.

Previous studies show that following disorientation children use the geometry of an enclosed space to locate an object hidden in one of the corners [e.g. (Harmer, L., & Spelke, E. (1996). Modularity and development: A case of spatial reorientation. "Cognition, 61," 195-232)]. These studies have used a disorientation procedure that involves rotating the viewer (with eyes closed). Here, we examine 18- to 25-month-olds' spatial coding in two disorientation tasks--involving either "viewer" or "space" rotation. Importantly, the rotational movements in both tasks could not be visually tracked. Children were tested in either task (viewer- or space-movement) from either inside or outside a triangular (isosceles) space (with one unique and two equivalent corners). In the viewer-movement task, performance was above chance, regardless of which corner contained the object. In the space-movement task, performance was above chance at only the unique corner. On both tasks, performance was better from inside the space than from outside. The implications for how children determine location are discussed.

Six experiments examined whether there were circumstances in which toddlers could use landmarks for spatial reorientation. Findings confirmed that geometric information is used for reorientation by toddlers, but give reason to doubt that the use of this information is achieved using a module impenetrable to nongeometric information. (Author/KB)

The article presents a study on location coding. It states that the ability to find objects in the environment is adaptively essential for mobile organisms. Research on this consideration showed that even toddlers have considerable spatial skill and that they use geometric features of the spatial environment to identify object location. It has also been mentioned that these results manifest innate geometric abilities, but there is evidence that these early spatial skills are not simply geometric. The article also presents some experimental findings that provide the basis for a different interpretation of spatial development.

Both animals and human toddlers can find an object in a rectangular enclosure after they have been disoriented. They use geometric cues (relative lengths of walls) to discriminate among different corners (e.g. long wall to the left, short to the right). It has been claimed that this ability is ‘modular’, i.e. exclusively geometric. The present study demonstrates that the ability toddlers exhibit is a more general one, namely, an ability to discriminate relative quantity. Using a square enclosure, we show that toddlers use the relative sizes of the figures on different walls to characterize different corners. We also show that they do not use simple non-relative features to distinguish different corners. Possible reasons for differences in the ability to use relative versus non-relative cues are discussed. [ABSTRACT FROM AUTHOR]

Recent findings indicate that toddlers can use geometric cues to locate an object hidden in a corner of a rectangular room after being disoriented [Cognition 61 (1996) 195]. It has been suggested that locating the object involves reestablishing one’s initial heading. The present experiments examine search behavior after disorientation. We find that toddlers go directly to a particular corner, indicating that they do not have to reestablish their original heading. It also has been suggested that toddlers ability to use geometric cues is limited to surrounding spaces. We find that toddlers can locate an object from outside as well as from inside a space, although the task is harder from outside. Based on these results, we argue that while toddlers do not represent their position relative to a particular portion of a space, they nevertheless may represent their position relative to the entire space (i.e., outside vs. inside). [Copyright &y& Elsevier]