Age-related changes in odor discrimination

Odor naming and recognition memory are poorer in children than in adults. This study explored whether such differences might result from poorer discriminative ability. Experiment 1 used an oddity test of discrimination with familiar odors on 6-year-olds, 11-year-olds, and adults. Six-year-olds were significantly poorer at discrimination relative to 11-year-olds and adults, who did not differ. Experiment 2 used the same procedure but with hard-to-name visual stimuli and compared only 6-year-olds with adults (as with the remaining experiments in this study). There was no difference in performance between these groups. Experiment 3 used the same procedure as Experiment 1 but with less familiar odors. Six-year-olds were significantly poorer at discrimination than adults. In Experiment 4 the researchers controlled for verbal labeling by using an articulatory suppression task, with the same basic procedure as in Experiment 1. Six-year-old performance was the same as for Experiment 1 and significantly poorer than that of adults. Impoverished olfactory discrimination may underpin performance deficits previously observed in children. These all may result from their lesser experience with odors, relative to adults.     

Holistic processing of faces in preschool children and adults

Contrary to the encoding-switch hypothesis, recent research demonstrates that 6-year-olds do not rely solely on parts-based encoding to recognize upright faces. This research shows better recognition of face parts presented in the whole face than in isolation, indicating use of holistic encoding. The present study examined whether children younger than 6 years also recognize faces holistically. Four-year-olds, 5-year-olds, and adults were administered a part-whole face recognition task. Children below the age of 6 remembered parts from upright faces better when tested in the whole-face context than in isolation. This whole-face advantage did not occur when faces were inverted. Although children showed a smaller inversion decrement than adults and generally performed more poorly than adults, the different age groups showed similar patterns of performance, indicating that young preschoolers, like older children and adults, are able to recognize faces holistically.     

The Blicket Within: Preschoolers' Inferences About Insides and Causes

Four experiments examined children's inferences about the relation between objects' internal parts and their causal properties. In Experiment 1, 4-year-olds recognized that objects with different internal parts had different causal properties, and those causal properties transferred if the internal part moved to another object. In Experiment 2, 4-year-olds made inferences from an object's internal parts to its causal properties without being given verbal labels for objects or being shown that insides and causal properties covaried. Experiment 3 found that 4-year-olds chose an object with the same internal part over one with the same external property when asked which object had the same causal property as the target (which had both the internal part and external property). Finally, Experiment 4 demonstrated that 4-year-olds made similar inferences from causal properties to internal parts, but 3-year-olds relied more on objects' external perceptual appearance. These results suggest that by the age of 4, children have developed an understanding of a relation between an artifact's internal parts and its causal properties.     

行为表现与言语报告:3～5岁儿童的一级观点采择(英文)

为考察3~5岁儿童一级观点采择的行为表现与言语报告之间的潜在差异,本研究采用"单面镜"范式设计了两个实验。实验1中,54名儿童成对与实验者一起完成观点采择游戏,逻辑回归分析结果表明3-5岁儿童的行为表现不存在显著差异(B=?0.225,Wald=0.38,p=0.541)。方差分析也没有发现儿童的行为表现和言语报告存在差异。由于实验1中的编码系统存在一些局限,并且缺少对儿童偏好的控制,因此在实验2中进行了改进。实验2选择了另外60名3~5岁儿童完成藏玩具游戏。方差分析发现了实验范式类型(行为表现或言语报告)、年龄和性别的三因素交互作用(F(2,48)=3.55,p=0.037,η2=0.13)。结果表明随着年龄增加,男孩与女孩一级观点采择的行为表现都显著提高,而男孩言语报告的提高程度显著低于女孩。总体而言,考察儿童一级观点采择时,行为表现可能比言语报告提供更多信息。     

A New Look at Gaze: Preschool Children's Understanding of Eye-Direction

This study challenges the consensus view that children can judge what someone is looking at from infancy. In the first experiment 2-, 3-, and 4-year-old children were asked to judge what a person in a drawing was looking at and which of two people was “looking at” them. Only 6% of 2-year-olds and young 3-year-olds passed both gaze-direction tasks, but over 70% passed an analogous point-direction task. Most older 3-year-olds and 4-year-olds passed all three tasks. Experiment 2 compared children's ability to judge what the experimenter was looking at with performance on the picture tasks. Three-year-olds performed significantly worse than 4-year-olds on the real life and picture gaze tasks. Performances on the two types of gaze task were highly correlated. Experiment 3 included stimuli with the additional cue of head-direction. Even the younger children performed well on these stimuli. These results suggest that, regardless of task format, children cannot judge what someone is looking at from eye-direction alone until the age of 3 years. Weaknesses in the evidence supporting the consensus view are highlighted and discussed.     

Age-related changes in discrimination of unfamiliar odors

If odor perception involves mnemonic processes, differences in olfactory experience should affect discriminative ability. This was examined here by comparing discriminative performance in children and adults. Using an oddity test of discrimination, in Experiment 1 we tested 6-year-olds (G1), 11-year-olds (G6), and adults (A) on their ability to discriminate unfamiliar odors that varied either in quality (Q) or in quality and intensity (QI). G1 participants were poorer at discriminating the QI set, relative to G6 and A. In Experiment 2, we used an analogous visual procedure and confirmed that this age-related difference was olfactory specific. In Experiment 3, we repeated Experiment 1 but used an articulatory suppression task. G1 participants were poorer than G6 and A participants for both the Q and the QI sets. The implications of these findings for experiential accounts of odor perception and olfactory working memory are discussed.     

A further analysis of time bisection behavior in children with and without reference memory: the similarity and the partition task

Experiment 1 compared the temporal performance of 5-year-olds, 8-year-olds and adults in a bisection task with and without referent durations (similarity vs. partition). The results showed that temporal sensitivity was lower in the partition than in the similarity condition in children, whereas it was similar in these two conditions in the adults. In addition, the 5-year-olds produced a higher bisection point value in the partition than in the similarity task. Experiment 2, which examined changes in bisection performance over the trial blocks in the partition task, revealed that the 5-year-olds' bisection performance improved over the trial blocks, whereas the performance of the older participants did not. Further analyses revealed a greater variability in the establishment of the duration criterion in young children.     

Reliance on visual and verbal information across ontological kinds: What do children know about animals and machines?

In two experiments, we systematically examined the reliance on visual (external shape and features) and verbal (origins and internal structure) information in isolation, and together in the identification of animals and machines by 3-, 4-, and 5-year-olds, and adults. Experiment 1 examined the use of visual and verbal information independently in a visual classification task, a verbal classification task, and an induction task. Experiment 2 examined the relative weighting of visual and verbal information in an induction task and a categorization task. The three most important findings from Experiment 1 were that (a) children and adults can use either visual or verbal information to distinguish animals from machines; (b) all age groups classified items with mixed visual information as machines, a tendency that increased with age; and (c) with age, children became increasingly able to induce non-obvious properties, especially the non-obvious properties of machines. The findings from Experiment 2 indicate that the youngest and oldest participants relied on both visual and verbal information in the identification of animals and machines in categorization and induction tasks. Five-year-olds, however, relied only on visual information. As in Experiment 1, we observed a tendency to judge items with contrasting information as machines, suggesting that individuals utilize a more strict definition (both visually and verbally) for the category of animals. We discuss the implication of these results with respect to developmental differences in the use of perceptual and conceptual information across the ontological distinction between artifacts and natural kinds.     

Paired associate learning in Chinese children with dyslexia

A total of 82 Chinese 11- and 12-year-olds with and without dyslexia were tested on four paired associate learning (PAL) tasks, phonological awareness, morphological awareness, rapid naming, and verbal short-term memory in three different experiments. Experiment 1 demonstrated that children with dyslexia were significantly poorer in visual-verbal PAL than nondyslexic children but that these groups did not differ in visual-visual PAL performance. In Experiment 2, children with dyslexia had more difficulties in transferring rules to new stimuli in a rule-based visual-verbal PAL task as compared with children without dyslexia. Long-term retention of PAL was not impaired in dyslexic children across either experiment. In Experiment 3, rates of visual-verbal PAL deficits among children with dyslexia were all at or above 39%, the highest among all cognitive deficits tested. Moreover, rule-based visual-verbal PAL, in addition to morphological awareness and rapid naming ability, uniquely distinguished children with and without dyslexia even with other metalinguistic skills statistically controlled. Results underscore the importance of visual-verbal PAL for understanding reading impairment in Chinese children.     

Cross-cultural differences in cognitive development: attention to relations and objects

Growing evidence indicates a suite of generalized differences in the attentional and cognitive processing of adults from Eastern and Western cultures. Cognition in Eastern adults is often more relational and in Western adults is more object focused. Three experiments examined whether these differences characterize the cognition of preschool children in the two cultures. In Experiment 1, 4-year-olds from the two cultures (N=64) participated in a relational match-to-standard task in two conditions, with simple or richly detailed objects, in which a focus on individual objects may hurt performance. Rich objects, consistent with past research, strongly limited the performance of U.S. children but not Japanese children. In Experiment 2, U.S. and Japanese 4-year-olds (N=72) participated in a visual search task that required them to find a specific object in a cluttered, but organized as a scene, visual field in which object-centric attention might be expected to aid performance and relational attentional pattern may hinder the performance because of relational structure that was poised by the scene. U.S. children outperformed Japanese children. In Experiment 3, 4-year-olds from both cultures (N=36) participated in a visual search task that was similar to Experiment 2 but with randomly placed objects, where there should not be a difference between the performance of two cultures because the relational structure that may be posed by the scene is eliminated. This double-dissociation is discussed in terms of implications for different developmental trajectories, with different developmental subtasks in the two cultures.     

The Effects of Feedback on Perseverative Errors in Preschool Aged Children

Research using the Dimensional Change Card Sort (DCCS) showed that young children are usually able to sort accurately by an initial rule but are unable to switch to a new rule when the two rules conflict. In 2 experiments, the DCCS was modified to study the effects of feedback on 3- to 5-year-old children in a problem-solving task. In Experiment 1, half of the children in each of two age groups (36 to 44 months and 52 to 60 months) were administered the DCCS task using the standard (no feedback) procedure and the other half received feedback on their post-switch responses. Children who received feedback were able to categorize according to the new (correct) rule, whereas the children in the younger age group who did not receive feedback continued to perseverate. Experiment 2 with 3-year-olds replicated the results from Experiment 1 but found that children's successful performance with feedback on the card-sorting task did not lead to improved performance on the post-switch phase of a subsequent DCCS task. Successful performance under conditions of feedback in both studies implies that 3-year-olds are capable of shifting their response mode from one rule to an alternate rule under conditions that offer clear guidance. Poor performance on the standard version is interpreted to be a reflection of the inability to monitor their own task performance in the absence of clear contextual cues.     

The development of landmark and beacon use in young children: evidence from a touchscreen search task

Children ages 2, 3 and 4 years participated in a novel hide-and-seek search task presented on a touchscreen monitor. On beacon trials, the target hiding place could be located using a beacon cue, but on landmark trials, searching required the use of a nearby landmark cue. In Experiment 1, 2-year-olds performed less accurately than older children on landmark trials but performed equivalently on beacon trials. In Experiment 2, the number of items on the screen was reduced and 2-year-olds' performance improved. Use of the landmark transformation technique in Experiment 3 revealed that older children formed a more precise landmark-target spatial relationship than 2-year-olds. Experiment 4 showed that the transformation itself was not responsible for the youngest participants' decreased accuracy in Experiment 3. Overall, beacons were utilized effectively by all participants, but the use of landmark cues is refined between the ages of 2 and 4.     

Word learning and phonetic processing in preschool-age children

Consonants and vowels have been shown to play different relative roles in different processes, including retrieving known words from pseudowords during adulthood or simultaneously learning two phonetically similar pseudowords during infancy or toddlerhood. The current study explores the extent to which French-speaking 3- to 5-year-olds exhibit a so-called “consonant bias” in a task simulating word acquisition, that is, when learning new words for unfamiliar objects. In Experiment 1, the to-be-learned words differed both by a consonant and a vowel (e.g., /byf/-/duf/), and children needed to choose which of the two objects to associate with a third one whose name differed from both objects by either a consonant or a vowel (e.g., /dyf/). In such a conflict condition, children needed to favor (or neglect) either consonant information or vowel information. The results show that only 3-year-olds preferentially chose the consonant identity, thereby neglecting the vowel change. The older children (and adults) did not exhibit any response bias. In Experiment 2, children needed to pick up one of two objects whose names differed on either consonant information or vowel information. Whereas 3-year-olds performed better with pairs of pseudowords contrasting on consonants, the pattern of asymmetry was reversed in 4-year-olds, and 5-year-olds did not exhibit any significant response bias. Interestingly, girls showed overall better performance and exhibited earlier changes in performance than boys. The changes in consonant/vowel asymmetry in preschoolers are discussed in relation with developments in linguistic (lexical and morphosyntactic) and cognitive processing.     

Factors affecting children's graphic symbol use in the third year: Language,similarity, and iconicity

The question addressed in this study is whether the claim that children understand the symbolic status of pictures by the middle of their third year is an overestimate of their ability. Specifically, we asked whether children use language if possible to facilitate their performance in graphic symbolic tasks. Language (availability of verbal labels) was manipulated along with iconicity (degree of resemblance between symbol and referent) and perceptual similarity (between choice items) in a series of four experiments. Children 2.5 and 3 years old were presented with a graphic symbol for 4 s and immediately asked to choose the object depicted (referent) from two choice objects. In Study 1, degree of iconicity between picture and referent was varied and both choice objects had the same verbal label. The 2.5-year-olds failed to use any pictures or replicas as symbols. The 3-year-olds performed well with all types of symbols and better with highly iconic symbols. In Study 2, verbal label availability was manipulated by presenting choice objects having the same or different labels and by varying familiarity of labels. The 2.5-year-olds performed at chance when verbal labels were unavailable but above chance when they were available. The 3-year-olds were above chance in all conditions but performed less well when verbal labels were unavailable. Study 3 confirmed that young children use language to mediate picture symbol use. When 2.5-year-olds were provided with subordinate verbal labels in the matching task, subsequent performance was good even when choice objects had the same basic level verbal label. In Study 4, verbal label availability was contrasted with perceptual similarity between choice objects. When verbal labels could be used and choice objects were dissimilar, performance was best, and when verbal labels could not be used and choice objects were similar, it was worst. The results suggest that children's developing understanding of the symbolic function of pictures is tenuous in the third year, and is supported by their use of verbal labels.     

Color term knowledge does not affect categorical perception of color in toddlers

Categorical perception of color is shown when colors from the same category are discriminated less easily than equivalently spaced colors that cross a category boundary. The current experiments tested various models of categorical perception. Experiment 1 tested for categorical responding in 2- to 4-year-olds, the age range for the onset establishment of color term knowledge. Experiment 2 tested for categorical responding in Himba toddlers, whose language segments the color space differently from the way in which the English language does so. Experiment 3 manipulated the conditions of the task to explore whether the categorical responding in Experiments 1 and 2 was equivalent to categorical perception. Categorical perception was shown irrespective of naming and was not stronger in those children with more developed color term knowledge. Cross-cultural differences in the extent of categorical perception were not found. These findings support universalistic models of color categorization and suggest that color term knowledge does not modify categorical perception, at least during the early stages of childhood.     

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.     

Age-related changes in children's use of external representations.

This study explored children's use of external representations. Experiment 1 focused on representations of self: Self-recognition was assessed by a mark test as a function of age (3 vs. 4 years), delay (5 s vs. 3 min), and media (photographs vs. drawings). Four-year-olds outperformed 3-year-olds; children performed better with photographs than drawings; and there was no effect of delay. In Experiment 2, 3- and 4-year-olds used a delayed video image to locate a sticker on themselves (self task) or a stuffed animal (other task). The 2 tasks were positively correlated with age and vocabulary partialed out. Experiment 3 used a search task to assess whether children have particular difficulty using external representations that conflict with their expectations: 3- and 4-year-olds were informed of an object's location verbally or through video: on half of the trials, this information conflicted with children's initial belief. Three-year-olds performed worse than 4-year-olds on conflict trials, indicating that assessments of self and other understanding may reflect children's ability to reason about conflicting external representations.     

Five-year-old children's difficulty with false belief when the sought entity is a person

A total of 153 children (excluding those who erred on control questions), mainly 5 and 7 years of age, participated in two experiments that involved tests of false belief. In the task, the sought entity was first at Location 1 and then, unknown to the searching protagonist, it moved to Location 2. In Experiment 1, performance was well below ceiling in 5-year-olds when the sought entity was a person, and this contrasted with a task in which the sought entity was a physical object. Performance was especially inaccurate when the sought person moved of his or her own volition rather than when the sought person was requested to move by a third party. Interestingly, 5-year-olds were more likely to nominate Location 1 when asked where the searching protagonist would look first than when asked what he or she would do next. In Experiment 2, however, 5-year-olds also tended to nominate Location 1 following a question that included the word "first" even in a test of true belief--a patently incorrect response. Altogether, the results suggest that 5-year-old children have considerable difficulty with a test of false belief when the sought entity is a person acting under his or her own volition. This suggests that 5-year-olds' handle on states of belief is surprisingly fragile in this kind of task.     

Melting chocolate and melting snowmen: analogical reasoning and causal relations

Children's performance in the classical a:b::c:d analogy task is traditionally very poor prior to the Piagetian stage of formal operations. The interpretation has been that the ability to reason about higher-order relations (the relations between the a:b and c:d parts of the analogy) is late-developing. However, an alternative possibility is that the relations used to date in the analogies are too difficult for younger children. Two experiments presented children aged 3, 4 and 6 years with a:b::c:d analogies which were based on relations of physical causality such as melting and cutting, for example chocolate bar:melted chocolate::snowman:melted snowman. Understanding of these particular causal relations is known to develop between the ages of 3 and 4 years. It was found that even 3-year-olds could solve the classical analogies if they understood the causal relations on which they were based.     

Test sample selection by preschool children: Honoring diversity

In a test of an inductive inference, preschool children's selection of objects was examined. In Experiment 1, 4-year-olds selected diverse objects first in sequential selections; in Experiment 2, adults and 4-year-olds, but not 3-year-olds, made similar selections under the same conditions. A defective object led subjects in all age groups to test a similar object. In Experiment 3, 4-year-olds chose to test a pair of dissimilar objects rather than a pair of similar objects, but 3-year-olds did not. Three-year-olds' selections were independent of diversity. In Experiment 4, we attempted to emphasize the diversity of objects for 3-year-olds. Their first task was to select an object that was the same as or different from a target object. The subjects responded correctly in this task but did not prefer to test diverse objects. Experiment 5 showed that neither 3- nor 4-year-olds have a bias to select nondiverse objects in a nontest context. The findings indicate that children as young as 4 years old value diverse evidence in induction.