Developmental trends in the understanding of perceptual adaptation

In the first of three studies, kindergartners, third graders, and sixth graders were questioned to determine whether they comprehend five types of perceptual adaptation or contrast effects. The results indicated little consistency among kindergartners, but there were strong improvements by the third-grade level, and at the sixth-grade level almost all of the children were showing perfect performance, demonstrating comprehension of the five forms of perceptual adaptation. In the second and third studies, children and adults were placed in a situation in which adaptation to temperature and weight could occur, and they were asked to predict subsequent perceptions. Correct performance in these studies generally occurred at later ages than in Study 1 with even college students showing incorrect performance in some cases. However, the age trends shifted quite markedly depending upon the nature and structure of the task. The results were consistent with a theory stressing the relation of early formed schemas in the form of memory traces of experiences to later appearing and more abstract schemas. The results show the importance of studying older children when considering developing theories of mind.     

Developmental and individual differences in pure numerical estimation

The authors examined developmental and individual differences in pure numerical estimation, the type of estimation that depends solely on knowledge of numbers. Children between kindergarten and 4th grade were asked to solve 4 types of numerical estimation problems: computational, numerosity, measurement, and number line. In Experiment 1, kindergartners and 1st, 2nd, and 3rd graders were presented problems involving the numbers 0-100; in Experiment 2, 2nd and 4th graders were presented problems involving the numbers 0-1,000. Parallel developmental trends, involving increasing reliance on linear representations of numbers and decreasing reliance on logarithmic ones, emerged across different types of estimation. Consistent individual differences across tasks were also apparent, and all types of estimation skill were positively related to math achievement test scores. Implications for understanding of mathematics learning in general are discussed.     

Explaining teacher-student interactions in early childhood: An interpersonal theoretical approach

The present study used an interpersonal theoretical perspective to examine the interactions between Dutch teachers and kindergartners. Interpersonal theory provides explanations for dyadic interaction behaviors by stating that complementary behaviors (dissimilar in terms of control, and similar in terms of affiliation) elicit and sustain each other. We observed 69 kindergarten children (M_age = 5.79 years) and their 37 regular teachers during a dyadic interaction task. Every 5 s, independent observers rated teachers' and children's behaviors along the interpersonal dimensions of control and affiliation. Teachers reported on children's shyness and the quality of the teacher-child relationship. Multilevel modeling provided correlational evidence for complementarity within and between dyads. Cross-lagged analyses revealed that teachers showed complementarity for control and that children showed complementarity for affiliation. Children also reacted complementarily with respect to control but only if they were shy or shared positive relationships with their teachers. Implications for theory and practice are discussed.     

The influence of object conceptions on the mechanical intuitions of children and adults

This research examines how initial conceptualizations of objects and space exert an influence on predictions about the physical world but simultaneously lead the naïve to misconstrue a dynamic event. In four investigations, children (kindergartners, third graders, and sixth graders) and adults predicted where an oscillating screen would contact an object occluded by the screen's motion, a task adapted from the infant literature which is used to assess early knowledge of the solidity constraint on object motion. Participants demonstrated remarkable proficiency in anticipating the point of contact despite the formal geometric complexity of the event. However, although predictions were close approximations of the parameters objectively determinable for the event, responses were universally biased; participants systematically underestimated the distance the screen would travel to contact the object. Participants' responses were never in violation of the principle: One object cannot pass into the space occupied by another. Children and adults used different strategies to achieve their predictions, so the pattern of misconstruals across task parameters were developmentally related; however, the direction of the misconstrual was developmentally invariant. The findings are evaluated in terms of how initial knowledge of objects constrains intuition about physical events.     

What can the same–different task tell us about the development of magnitude representations?

We examined the development of magnitude representations in children (Exp 1: kindergartners, first-, second- and sixth graders, Exp 2: kindergartners, first-, second- and third graders) using a numerical same-different task with symbolic (i.e. digits) and non-symbolic (i.e. arrays of dots) stimuli. We investigated whether judgments in a same-different task with digits are based upon the numerical value or upon the physical similarity of the digits. In addition, we investigated whether the numerical distance effect decreases with increasing age. Finally, we examined whether the performance in this task is related to general mathematics achievement. Our results reveal that a same-different task with digits is not an appropriate task to study magnitude representations, because already late kindergarteners base their responses on the physical similarity instead of the numerical value of the digits. When decisions cannot be made on the basis of physical similarity, a similar numerical distance effect is present over all age groups. This suggests that the magnitude representation is stable from late kindergarten onwards. The size of the numerical distance effect was not related to mathematical achievement. However, children with a poorer mathematics achievement score seemed to have more difficulties to link a symbol with its corresponding magnitude.     

Children's cognitive maps of large-scale spaces: Effects of exploration,direction, and repeated experience

Kindergarteners and third graders (mean ages 5–10 and 8–9 years) repeatedly encountered a model town and then constructed the town from memory. In Experiment 1, the effect of different types of exploration on the development of a cognitive map was assessed. Children who were directed to walk within the town placed buildings more accurately than children who had walked along the town's perimeter. Children who walked within the town and were directed to the spatial relationships among buildings had the highest placement accuracy. Third graders were more accurate than kindergarteners across the three types of exploration. In Experiment 2, children were permitted to explore the town alone for an unlimited amount of time. Under these conditions, third graders still placed buildings more accurately than kindergarteners. A comparison of Experiments 1 and 2 indicated that children developed more accurate cognitive maps when motor activity and attention were directed by the experimenter as opposed to being directed by the child. Accuracy improved with repeated walks and constructions in both experiments, and the results of Experiment 3 suggested that constructing facilitated the development of the cognitive map as much as walking. It was concluded that third graders' cognitive maps were more accurate than kindergarteners' maps due to differences in the speed of acquisition and storage of spatial information.     

Evidence for a Spatial–Numerical Association in Kindergartners Using a Number Line Task

In Western cultures, small numbers are often associated with the left and large with the right space. We investigated whether this association is already present in kindergartners and second graders. Children (N = 59) estimated the position of numbers on a number line that was labeled either with a small number on the left side and a large number on the right side (i.e., left-to-right orientation) or vice versa (i.e., right-to-left orientation). The estimations were less accurate if the number line was oriented from right to left and if the children started with this condition. The results suggest that already kindergartners possess a culture-typical spatial–numerical association that develops before the acquisition of reading and writing skills and significantly affects the accuracy of numerical estimations. The performance of second graders, too, was affected by the orientation of the number line, but to a smaller degree than that of kindergartners.     

Directed forgetting in young children: Evidence for a production deficiency

When people are cued to forget a previously studied list of items and to learn a new list instead, such cuing typically leads to forgetting of the first list and to memory enhancement of the second. In two experiments, we examined such listwise directed forgetting in children (and adults), using a forget cue that placed either high emphasis or low emphasis on the need to forget. In the low-emphasis condition, (adult-like) List 1 forgetting was present in fourth graders, but not in first graders (and kindergartners); in contrast, in the high-emphasis condition, (adult-like) List 1 forgetting was present from first grade on. Only fourth graders showed (adult-like) List 2 enhancement, regardless of task instruction. The finding that first graders showed List 1 forgetting only in the high-emphasis condition points to a production deficiency in first graders’ directed forgetting, suggesting that the children are capable of intentional forgetting but fail to do so spontaneously. The finding that first graders showed List 1 forgetting without List 2 enhancement suggests that the two directed-forgetting effects are mediated by different processes with different developmental trajectories.     

Numerical Estimation in Children for Both Positive and Negative Numbers

Numerical estimation has been used to study how children mentally represent numbers for many years (e.g., Siegler & Opfer, 2003). However, these studies have always presented children with positive numbers and positive number lines. Children’s mental representation of negative numbers has never been addressed. The present study tested children in the 2nd, 4th, and 6th grades to assess their mental representations of both positive and negative numbers using a standard numerical estimation task. We replicated the shift from a logarithmic to linear representation for positive numbers (0–1,000 scale) in that 2nd graders represented positive numbers logarithmically, but 4th and 6th graders represented the numbers linearly. Furthermore, children’s representation of negative numbers paralleled their representations of positive numbers and showed the same shift from a logarithmic representation at Grade 2 to linear representations at Grades 4 and 6. This is the first study to provide data on children’s representation of negative numbers, and the implications of these findings are discussed.     

Developmental differences in response processing

Three age groups (kindergartners, fourth graders, and adults) were compared in their processing of response decisions in a two-choice reaction time task. Manipulation of spatial stimulus-response compatibility resulted in age-related differential effects on reaction time performance. For the younger children, selecting the appropriate response for an incompatibly paired stimulus light required proportionately longer processing time than for older subjects. Similar results were not found for performance under varying levels of response discriminability.     

Retrieval-induced forgetting in young children

A prominent theory of cognitive development attributes the poor performance that children show in many cognitive tasks to a general lack of inhibitory control. We tested this theory by examining children’s inhibitory capabilities in retrieval-induced forgetting (RIF), a memory task in which selective retrieval of previously studied material causes forgetting of related, nonretrieved material. Such forgetting is often attributed to inhibitory control processes, which supposedly suppress the nonretrieved items’ memory representation. We examined RIF in kindergartners, second graders, and adults, using both recall and recognition testing. Although all three age groups showed significant RIF in recall, only adults and second graders, but not kindergartners, showed RIF in recognition. Because inhibition-based RIF should be present in recall and recognition, these findings indicate that in adults and second graders, but not in kindergartners, RIF is mediated by inhibition. The results support the view of inefficient inhibitory processes in young children’s cognition.     

Preschoolers’ understanding of multiple orientations to reality: The adjectives task

Preschoolers’ understanding that an object can be accurately described using two different non-synonymous words was investigated using a task in which children (N = 36) had to judge which of two animals had provided correct adjectival labels for a series of pictures. For some pictures, only one animal provided a correct adjective, for some both animals were correct, and for some neither was correct. For all types of judgement, 4-year-olds outperformed 3-year-olds. Children in both age groups performed worst on trials where both animals were correct. Children's performance on the adjectives task related to concurrent understanding of the appearance–reality distinction, but not to false-belief task performance. Implications for children's mentalizing development are discussed.     

Consistency-based compliance: when and why do children become vulnerable?

This study examines the nature and development of behavioral consistency pressures in children. Specifically, we examined the effectiveness of the foot-in-the-door procedure in producing consistent prosocial behavior and self-attributions in kindergartners and second and fifth graders. Children were either induced to comply with a request to share prize coupons or were not given this initial prosocial experience. Those who complied either were labeled as helpful by an adult or were not. Later, children were given the opportunity to help under public or private circumstances. Moreover. children's understanding of trait stability, their internal preference for consistent behavior, and their belief that adults prefer behavioral consistency were assessed. Consistent responding began to occur within the foot-in-the-door procedure in the second grade, and this developmental shift was paralleled by a shift in children's understanding of trait stability. Furthermore, once the foot-in-the-door effect appeared among the second and fifth graders, its strength was significantly affected by the children's internal preference for consistency.     

Development of Map Construction Skills in Childhood

Two studies examined children's map construction skills when drawing demands were removed from the task and scenes were highly simplified. Study 1 compared the performance of first graders and third graders on their ability to preserve configuration during transformation of pictured arrays from eye-level to aerial views. For children with difficulties, Study 2 exposed groups to enhanced vantage points, either pictured from an elevated view or displayed with actual blocks, to investigate effects of support on performance. Results on eye-level to aerial transformations showed that children's ability to map spatial relations developed significantly between the first and third grades, basic configuration skills were gender-neutral, and specificity of details was better for boys by third grade. Enhanced vantage points significantly improved configuration accuracy for both grades (favoring first graders) and both genders (favoring girls). Enhancements eliminated depth errors that were common in arrays with occlusions. In sum, improvement in map construction skills between first grade and third grade demonstrated increased understanding of alternative spatial perspectives, and enhanced vantage points promoted use of projective spatial concepts that were already active in younger children.     

儿童数字估计的表征模式与发展

探讨中国儿童数字估计的表征模式与发展趋势。包括两个实验,均采用数字线估计任务,实验一以92名幼儿园、一年级及二年级儿童为被试,考察其在0~100范围的数字估计,结果显示,幼儿园儿童在数字估计更多地采用对数表征,而一二年级的儿童在数字估计中更多地采用线性表征;实验二以86名一、三、五年级儿童为被试,考察其在0~1000范围的数字估计,结果显示,一年级儿童有一半采用对数表征,另一半采用线性表征,而三五年级儿童大多采用线性表征。中国儿童的数字估计表现出与美国儿童相同的发展模式,都是由不精确的对数表征逐步向精确的线性表征发展;人的数表征有多种形式,即使在同一年龄阶段,也会因任务难度的不同而选择不同的表征模式。中国儿童精确数字估计能力的出现要早于美国儿童。     

Bottom-up and top-down dynamics in young children's executive function: Labels aid 3-year-olds’ performance on the Dimensional Change Card Sort

Executive function (EF) improves between the ages of 3 and 5 and has been assessed reliably using the Dimensional Change Card Sort (DCCS), a task in which children first sort bivalent cards by one dimension (e.g., shape) and then are instructed to sort by a different dimension (e.g., color). Three-year-olds typically perseverate on the pre-switch dimension, whereas 5-year-olds switch flexibly. Labeling task stimuli can facilitate EF performance (0110 and 0060), but the nature of this effect is unclear. In 3 experiments we examined 2 hypotheses deriving from different theoretical perspectives: first, that labels facilitate performance in a more bottom-up fashion, by biasing attention to relevant task rules (Kirkham et al., 2003); and second, that labels aid performance in a more top-down fashion by prompting reflection and an understanding of the hierarchical nature of the task (Zelazo, 2004). Children performed better on the DCCS when labels referred to the relevant sorting dimension (Experiment 1). This was a function of the content of the labels rather than the change in auditory signal across phases (Experiment 2). Furthermore, labeling the opposite dimension only did not have a symmetrically negative effect on performance (Experiment 3). Together, these results suggest external, verbal labels bias children to attend to task-relevant information, likely through interaction with emerging top-down, endogenous control.     

Learning new vocabulary during childhood: Effects of semantic training on lexical consolidation and integration

Research suggests that word learning is an extended process, with offline consolidation crucial for the strengthening of new lexical representations and their integration with existing lexical knowledge (as measured by engagement in lexical competition). This supports a dual memory systems account, in which new information is initially sparsely encoded separately from existing knowledge and integrated with long-term memory over time. However, previous studies of this type exploited unnatural learning contexts, involving fictitious words in the absence of word meaning. In this study, 5- to 9-year-old children learned real science words (e.g., hippocampus) with or without semantic information. Children in both groups were slower to detect pauses in familiar competitor words (e.g., hippopotamus) relative to control words 24 h after training but not immediately, confirming that offline consolidation is required before new words are integrated with the lexicon and engage in lexical competition. Children recalled more new words 24 h after training than immediately (with similar improvements shown for the recall and recognition of new word meanings); however, children who were exposed to the meanings during training showed further improvements in recall after 1 week and outperformed children who were not exposed to meanings. These findings support the dual memory systems account of vocabulary acquisition and suggest that the association of a new phonological form with semantic information is critical for the development of stable lexical representations.     

The development of children’s early memory skills

A multitask battery tapping nonverbal memory and language skills was used to assess 60 children at 18, 24, and 30 months of age. Analyses focused on the degree to which language, working memory, and deliberate memory skills were linked concurrently to children’s Elicited Imitation task performance and whether the patterns of association varied across the different ages. Language ability emerged as a predictor of immediate Elicited Imitation performance by 24 months of age and predicted delayed performance at each age. In addition to the contributions of language, children’s abilities to search for and retrieve toys in the deliberate memory task were associated with their immediate Elicited Imitation performance at each age. In addition to language, working memory was positively associated with aspects of both immediate and delayed performance at all ages. The extent to which it was possible to replicate and extend previous cross-sectional work in this longitudinal study is discussed.     

The development of strategic memory: A modified microgenetic assessment of utilization deficiencies

Second-, third-, and fourth-grade children performed a multitrial sort-recall task, using different sets of stimulus items on each trial. Children were classified as utilizationally deficient if measures of sorting and/or clustering were initially below chance but increased over trials without a corresponding increase in recall. Children were classified as quasiutilizationally deficient if initial levels of strategy use were greater than expected by chance and increased over trials without concomitant increases in recall. More second and third graders were classified as utilizationally deficient than fourth graders, who were more likely to be classified as quasiutilizationally deficient than the younger children. Levels of recall and clustering were higher for second- and third-grade utilizationally deficient than for nonutilizationally deficient children, with this pattern being reversed for the fourth graders. Strategy classification was not predicted by measures of intelligence or metamemory. The results were discussed in terms of Miller's (1990) model of strategy development.     

4~8年级学生分数数量表征的准确性及形式

在分数学习中,分数数量表征是非常重要的方面。本研究利用数字线估计任务对四到八年级学生分数数量表征的情况进行探索。研究结果表明：随着年级升高,被试分数数量表征的准确性也随之提高;被试对单位分数和非单位分数表征的准确性存在显著差异,表现为对单位分数表征的准确性显著高于对非单位分数的表征,这种差异在低年级显著,随着年级的增长,差异逐渐消失;四到八年级学生在0~3数字线上,对分数数量的表征表现为线性形式而非对数形式,且这种线性表征形式是在六年级开始出现并随着年龄增长逐渐发展起来的。中西方儿童在分数数量表征的准确性和形式上有相似的发展路径,但是在表征准确性上中国儿童更高、线性形式出现年级上中国儿童可能更早。