Three experiments explored the development of three linguistic aspects of more in children's speech. Subjects were 56 children between the ages of 2;6 and 6;0. Experiment 1 addressed the nature of the early semantic content of more. Experiment 2 examined the child's differentiation of mass more from count more. Experiment 3 explored the child's use of more as a comparative marker on adjectives. The results suggest, first, that the child initially stores the meaning of more with a prototype, rather than with some more systematic, featural representation. In addition, children's linguistic understanding of the dual use of more as a quantifier of mass amounts and count amounts does not appear to develop until long after they have been using more appropriately in unambiguous contexts. Finally, children learn to use more as a marker on comparatives only after they have acquired -er as a comparative marker, and some time after they have been using more successfully in nonadjectival constructions.
Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N=157) learned about estimation either by comparing alternative solution strategies or by reflecting on the strategies one at a time. At posttest and retention test, students who compared were more flexible problem solvers on a variety of measures. Comparison also supported greater conceptual knowledge, but only for students who already knew some estimation strategies. These findings indicate that comparison is an effective learning and instructional practice in a domain with multiple acceptable answers.
Children under 3½ years of age or so are often thought to produce the same types of scribbles for writing and drawing. We tested this idea by asking Chinese 2- to 6-year-olds to write and draw four targets. In Study 1, Chinese adults judged the status of the productions as writings or drawings. The adults performed significantly above the level expected by chance even with the productions of 2- to 2½-year-olds. In Study 2, we examined specific characteristics of the children's writings and drawings. Although the younger children's scribbles bore little resemblance to the correct characters, they tended to be smaller, sparser, and more angular than their artwork, with less filling in. Differences were also found in paper use and implement use. Children did not appear to distinguish writing from drawing for their own names before they did so for other targets.
The aim of the present study was twofold: first, to investigate the effects of spatial precues on the execution of rapid aiming in children aged 7, 9, and 11 and second, to provide a kinematic support to the investigation of the role of precues in aiming tasks performed under temporal constraints. Four precuing conditions were used, where participants received: (a) no precue of any type, (b) advance information on direction, (c) advance information on amplitude, and (d) complete information on the forthcoming movement. Our results showed that precuing the spatial dimensions of movement shortens reaction times, that such shortening is a function of the number of precued parameters, and that spatial precues modify the kinematics of the children's rapid aiming movements. Peak velocity increased with direction and/or amplitude, suggesting that precues play a significant role in motor preparation. Moreover, the accuracy results indicate that direction precuing induces a proactive directional regulation. Finally, direction and amplitude appear to be independently specified in children.
Four- to 11-year-old children (N = 133) made duration, distance, and speed judgments on a Piagetian task where two cars ran on two parallel tracks. Special effort was made to make duration judgment tasks and distance judgment tasks comparable. Among younger children, difficulties of duration judgments and distance judgments were approximately the same. Additionally, temporal attributes had nearly the same effects on duration judgments as spatial attributes had on distance judgments, and spatial attributes had nearly the same effects on duration judgments as temporal attributes had on distance judgments. Among older children, distance judgments were easier than duration judgments, and the above-mentioned symmetry in effects of temporal and spatial attributes decreased somewhat. Temporal and spatial attributes affected speed judgments equally, across age groups.
Using concepts and tools of a dynamical system approach in order to understand motor coordination underlying graphomotor skills, the aim of the current study was to establish whether the basic coordination dynamics found in adults is already established in children at elementary school, when handwriting is trained and eventually acquired. In the study, 45 children and 9 adults volunteered to copy two series of 13 ellipsoid shapes. These shapes were generated by manipulating the relative phase between 0° and 180° of two orthogonal oscillators in two orientations. Findings showed that although children from an early age onward and adults reproduced straight lines precisely (i.e., 0° and 180°), the former drew ellipsoid shapes in a less eccentric fashion than the latter (i.e., ∼90° in all children rather than ∼60° and 120° in adults). This tendency to write in a rounder fashion persists until 11 years of age, suggesting that the coordination dynamics underlying graphomotor skills and tentatively shaping the coordinated activity involved in adult handwriting appears only later, probably due to increasing constraints on speed.
One hundred eight children 8, 11, and 14 years old selected one auditory message from two (male-female voice cue). Retention of target and distracting words was tested. Fifty-four control Ss heard the target message alone. Contrary to some earlier studies, distraction hindered the target performance of younger children more than older children. In the experimental groups target retention increased linearly with age but distraction retention remained constant. Intrusions from the distracting message during the selection task decreased greatly with increasing age. These and other results were interpreted as showing that the superior selective listening performance of older children is due not to a greater ability to filter out distracting material at an early stage of processing, but in large part to an ability to inhibit intrusions from the distracting material during the selection task.
This study investigated infants' rapid learning of two novel words using a preferential looking measure compared with a preferential reaching measure. In Experiment 1, 21 13-month-olds and 20 17-month-olds were given 12 novel label exposures (6 per trial) for each of two novel objects. Next, in the label comprehension tests, infants were shown both objects and were asked, "Where's the [label]?" (looking preference) and then told, "Put the [label] in the basket" (reaching preference). Only the 13-month-olds showed rapid word learning on the looking measure; neither age group showed rapid word learning on the reaching measure. In Experiment 2, the procedure was repeated 24h later with 10 participants per age group from Experiment 1. After a further 12 labels per object, both age groups now showed robust evidence of rapid word learning, but again only on the looking measure. This is the earliest looking-based evidence of rapid word learning in infants in a well-controlled (i.e., two-word) procedure; our failure to replicate previous reports of rapid word learning in 13-month-olds with a preferential reaching measure may be due to our use of more rigorous controls for object preferences. The superior performance of the younger infants on the looking measure in Experiment 1 was not straightforwardly predicted by existing theoretical accounts of word learning.
In an attempt to determine whether it is necessary to postulate abstraction processes in infant categorization, three experiments assessed retention of category-level information and information specific to category members. Using a visual recognition memory procedure, 10- and 13-month-old infants were familiarized with category instances containing both shared dimensional information and idiosyncratic features. The addition of idiosyncratic features to members of the familiarization category enhanced specific item memory for 13-month-old infants. However, this was not the case for the younger infants. The results of within-category test comparisons indicated that 10-month-old infants regarded information common to all members of the category as more familiar than information specific to individual exemplars. This occurred despite evidence that specific item information was retained in memory and available for retrieval during recognition tests. The findings are discussed in relation to exemplar and abstraction models of categorization.
Behavioral, psychophysiological, and neuropsychological studies have revealed large developmental differences in various learning paradigms where learning from positive and negative feedback is essential. The differences are possibly due to the use of distinct strategies that may be related to spatial working memory and attentional control. In this study, strategies in performing a discrimination learning task were distinguished in a cross-sectional sample of 302 children from 4 to 14 years of age. The trial-by-trial accuracy data were analyzed with mathematical learning models. The best-fitting model revealed three learning strategies: hypothesis testing, slow abrupt learning, and nonlearning. The proportion of hypothesis-testing children increased with age. Nonlearners were present only in the youngest age group. Feature preferences for the irrelevant dimension had a detrimental effect on performance in the youngest age group. The executive functions spatial working memory and attentional control significantly predicted posterior learning strategy probabilities after controlling for age.
The characteristics of visual scanning over the 2- to 14-week age period were examined through repeated assessments conducted on a sample of 10 infants. Scanning patterns were measured using a bright-pupil corneal reflex system, and the stimuli consisted of various sets of static, moving, or flickering geometric figures. There appear to be a number of age-related changes in the dominant mode of visual scanning. At the youngest ages the infants' scanning often proved unrelated to the locations of the stimulus contours, and in instances where a stimulus figure was in fact attended the infants typically centered their regard on a single prominent feature. In contrast, as the infants grew older they more consistently directed their saccades toward stimulus contours, became increasingly disposed to scan between different stimulus features, and directed their saccades with increased accuracy. When a stimulus was flickering, however, the infants' scanning characteristics reverted to those typically found at younger ages. The mechanisms which might account for the effects of age and of stimulus quality on visual scanning are considered.
Human infants have an enormous amount to learn from others to become full-fledged members of their culture. Thus, it is important that they learn from reliable, rather than unreliable, models. In two experiments, we investigated whether 14-month-olds (a) imitate instrumental actions and (b) adopt the individual preferences of a model differently depending on the model's previous reliability. Infants were shown a series of videos in which a model acted on familiar objects either competently or incompetently. They then watched as the same model demonstrated a novel action on an object (imitation task) and preferentially chose one of two novel objects (preference task). Infants' imitation of the novel action was influenced by the model's previous reliability; they copied the action more often when the model had been reliable. However, their preference for one of the novel objects was not influenced by the model's previous reliability. We conclude that already by 14 months of age, infants discriminate between reliable and unreliable models when learning novel actions.
Since previous data suggested that the magnitude of orienting evidenced by cardiac deceleration increased over the first 16 weeks of life, 6- and 16-week-old infants were compared on various characteristics of orienting: habituation, dishabituation, and magnitude of deceleration to stimulus offset as well as to stimulus onset. Neither the change in stimulus following habituation trials nor the stimulus offset produced a large enough response to confidently evaluate age differences suggested by the data. Stimulus onset elicited a pronounced deceleration which for the two age groups was of equivalent magnitude on initial trials and declined similarly with stimulus repetition. It was suggested that similarity of the two age groups on these parameters was due to control of state within a narrow alert range, and that, in general, younger infants are less likely than older infants to show orienting when conditions for orienting are marginal.
An object's axis of elongation serves as an important frame of reference for forming three-dimensional representations of object shape. By several recent accounts, the formation of these representations is also related to experiences of acting on objects. Four experiments examined 18- to 24-month-olds' (N=103) sensitivity to the elongated axis in action tasks that required extracting, comparing, and physically rotating an object so that its major axis was aligned with that of a visual standard. In Experiments 1 and 2, the older toddlers precisely rotated both simple and complexly shaped three-dimensional objects in insertion tasks where the visual standard was the rectangular contour defining the opening in a box. The younger toddlers performed poorly. Experiments 3 and 4 provide evidence on emerging abilities in extracting and using the most extended axis as a frame of reference for shape comparison. Experiment 3 showed that 18-month-olds could rotate an object to align its major axis with the direction of their own hand motion, and Experiment 4 showed that they could align the major axis of one object with that of another object of the exact same three-dimensional shape. The results are discussed in terms of theories of the development of three-dimensional shape representations, visual object recognition, and the role of action in these developments.
Accurate representation of a changing environment requires individuation-the ability to determine how many numerically distinct objects are present in a scene. Much research has characterized early individuation abilities by identifying which object features infants can use to individuate throughout development. However, despite the fact that without memory featural individuation would be impossible, little is known about how memory constrains object individuation. Here, we investigated infants' ability to individuate multiple objects at once and asked whether individuation performance changes as a function of memory load. In three experiments, 18-month-old infants saw one, two, or three objects hidden and always saw the correct number of objects retrieved. On some trials, one or more of these objects surreptitiously switched identity prior to retrieval. We asked whether infants would use this identity mismatch to individuate and, hence, continue searching for the missing object(s). We found that infants were less likely to individuate objects as memory load grew, but that infants individuated more successfully when the featural contrast between the hidden and retrieved objects increased. These results suggest that remembering more objects may result in a loss of representational precision, thereby decreasing the likelihood of successful individuation. We close by discussing possible links between our results and findings from adult working memory.
Two experiments examined the effects of postevent information on 18-month-olds' event memory. Experiment 1 (N=60) explored whether children's memory was reinstated when action information was eliminated from the reinstatement and only object information was introduced. Experiment 2 (N=48) examined children's recall when either (a). information about the objects' target actions was replaced with new action information or (b). the original training objects were replaced with new objects. In an elicited-imitation paradigm, children were trained to perform six target actions, watched a video reinstatement 10 weeks later, and were tested for recall 24 h after reinstatement. Two results were found. First, a video reminder eliminating action information reinstated children's memory as effectively as a video containing object and action information. Second, children were reminded of their past training when during reinstatement action information was preserved and new objects were presented but were not reminded when object information was preserved and new actions were presented.
Recent work reporting neonatal auditory responses to complex tones generated by applying electrical square-wave stimuli to loudspeakers is reviewed with reference to the nature of the acoustic stimulus. Attention is particularly drawn to the harmonic structure of such tones in relation to the nonlinear frequency response of small loudspeakers. A band analysis of some “square-wave tones” is given to illustrate the difficulties of interpreting the results of work using such complex stimuli. The findings of the previous studies are ascribed essentially to differences in the stimulus bandwidth, rather than to differences in audiofrequency, and difficulties apparently generated by using differences in stimulus bandwidth as the sole explanation are at least partially resolved.
Cohen (1988; Cohen & Younger, 1984) has suggested that there is a shift in the perception of form sometime after 6 weeks of age. Prior to this age infants can remember the specific orientations of line segments, but cannot process and remember the angular relations that line segments can make. Experiment 1 used simple line stimuli with newborn infants to test this suggestion. Following habituation to a simple two-line angle the newborns dishabituated to a change of orientation but not to a change in angle, confirming Cohen and Younger's suggestion that orientation is a powerful cue in early shape perception. In Experiments 2 and 3 newborns were familiarized either to an acute or to an obtuse angle that changed its orientation over trials. On subsequent test trials the babies gave strong novelty preferences to a different angle. Alternative interpretations of the results are discussed, but these experimental findings are compatible with the suggestion that newborns can quickly learn to process angular relations, and that rudimentary form perception may not be dependent on a lengthy period of learning and/or maturation for its development.
It has been hypothesized that an evolutionarily ancient mechanism underlies the ability of human infants to detect and act upon the direction of eye gaze of another human face. However, the evidence from behavioral studies with infants is also consistent with a more domain-general system responsive to the lateral motion of stimuli regardless of whether or not eyes are involved. To address this issue three experiments with 4-month-old infants are reported that utilize a standard face-cueing paradigm. In the first experiment an inverted face was used to investigate whether the motion of the pupils elicits the cueing effect regardless of the surrounding face context. In the second experiment pupil motion and eye gaze direction were opposed, allowing us to assess their relative importance. In a third experiment, a more complex gaze shift sequence allowed us to analyse the importance of beginning with a period of mutual gaze. Overall, the results were consistent with the importance of the perceived direction of motion of pupils. However, to be effective in cueing spatial locations this motion needs to be preceded by a period of direct mutual gaze (eye contact). We suggest that evolution results in information-processing biases that shape and constrain the outcome of individual development to eventually result in adult adaptive specializations.
Muter, Hulme, Snowling, and Taylor (1997) claimed that measures of phoneme segmentation, and not measures of rhyme, predict young children's reading. They base this claim on the relative predictive success of two rhyme and two phoneme segmentation tasks. However, there is a problem with one of their two rhyme measures, the Rhyme Detection measure. The children were asked to select a choice word which "rhymes with or sounds like" a target word, but the authors only scored rhyme choices ("boat"-"coat") as correct. Choices of words with the same onset as the target ("train"-"tractor") were counted as mistakes, even though these latter choices also shared a common sound with the target. A better way to score the task is to count onset as well as rhyme choices as correct. The new score predicts reading and spelling as well as the phoneme tasks. This result is consistent with the hypothesis of Goswami and Bryant (1990) that sensitivity to onset and rhyme, as well as awareness of phonemes, plays a part in children's success in reading and to spelling.
J. A. Bowey, L. Vaughan, and J. Hansen (1998, Journal of Experimental Child Psychology, 68, 108-133) carried out two experiments on 6- and 7-year-old children's use of orthographic analogies in word reading. They reported that, following apparently stringent controls for phonological priming effects, beginning analogies (beak-bean) were more frequent in this age group than rime (beak-peak) analogies. From this, they concluded that beginning readers do not reliably use orthographic rimes in reading, even in the clue word task (p. 129). However, the clue word task was not used in this study. This comment highlights two problems with Bowey et al.'s paper. The first is a theoretical one, and the second is methodological. Firstly, Bowey et al. base their investigation on a misunderstanding of U. Goswami and P. E. Bryant's (1990, Phonological skills and learning to read, Hillsdale, NJ: Erlbaum) claims about the role of rhyme and analogy in beginning reading. Secondly, methodological weaknesses, in particular unintended intralist priming effects, seriously limit the conclusions that can be drawn from Bowey et al.'s booklet analogy task.
U. Goswami (1999, Journal of Experimental Child Psychology, 72, 210-219) argues that the findings of J. A. Bowey, L. Vaughan, and J. Hansen (1998, Journal of Experimental Child Psychology, 68, 108-133) are uninterpretable. This paper examines each of Goswami's criticisms of the methodology employed by Bowey et al. (1998). None can explain the differential analogy and phonological priming effects reported by Bowey et al. More fundamentally, none can explain the critical finding of Bowey et al. that, when phonological priming effects are controlled, the size of the end analogy effect is no greater than that of beginning and medial vowel analogy effects. Furthermore, some of Goswami's criticisms cast considerable doubt on the generalizability of findings from her version of the clue word task.
Phonological sensitivity at different grain sizes is a good predictor of reading acquisition in all languages. However, prior to any explicit tuition in alphabetic knowledge, phonological sensitivity develops at the larger grain sizes-syllables, onsets, and rimes-in all languages so far studied. There are also developmental differences in the grain size of lexical representations and reading strategies across orthographies. Phoneme-level skills develop fastest in children acquiring orthographically consistent languages with a simple syllabic (CV) structure, such as Finnish and Italian. For English, however, both "large" and "small" units are important for the successful acquisition of literacy.
This study explores incremental processing in spoken word recognition in Russian 5- and 6-year-olds and adults using free-viewing eye-tracking. Participants viewed scenes containing pictures of four familiar objects and clicked on a target embedded in a spoken instruction. In the cohort condition, two object names shared identical three-phoneme onsets. In the noncohort condition, all object names had unique onsets. Coarse-grain analyses of eye movements indicated that adults produced looks to the competitor on significantly more cohort trials than on noncohort trials, whereas children surprisingly failed to demonstrate cohort competition due to widespread exploratory eye movements across conditions. Fine-grain analyses, in contrast, showed a similar time course of eye movements across children and adults, but with cohort competition lingering more than 1s longer in children. The dissociation between coarse-grain and fine-grain eye movements indicates a need to consider multiple behavioral measures in making developmental comparisons in language processing.
Exogenous (stimulus-driven) orienting between 7 and 21 weeks of age was examined in 2 experiments using a display with multiple potential targets of attention. On each trial a small moving probe was used to draw attention to one side of the display or the other. This moving probe appeared simultaneously with 27 static bars. In the first experiment, sensitivity to the moving target was affected significantly by the spatial distribution of these red and green static bars for 14-week-olds but not for 8-week-olds. Sensitivity to the moving target was lower for 14-week-olds when most of the red bars appeared contralaterally to the moving target. This effect replicated a similar effect observed in J. L. Dannemiller (1998). The lack of a contralateral competition effect in Experiment 1 for the 8-week-olds may have occurred because I used a stronger motion stimulus for the younger infants in an attempt to hold the overall performance constant at the 2 ages. A second experiment using a weaker motion stimulus showed that this contralateral competition effect was observable over the entire age range from 7 to 21 weeks of age. Thus as early as 7 weeks of age, sensitivity for a small moving stimulus can be significantly influenced by the simultaneous presence of competing targets of attention in the visual field. Large increases in overall sensitivity were also found across the age range from 7 to 21 weeks. Results are discussed in terms of the development of putative competition mechanisms involved in exogenous orienting.
We explored whether a rising trend to blindly "overcopy" a model's causally irrelevant actions between 3 and 5 years of age, found in previous studies, predicts a more circumspect disposition in much younger children. Children between 23 and 30 months of age observed a model use a tool to retrieve a reward from either a transparent or opaque puzzle box. Some of the tool actions were irrelevant to reward retrieval, whereas others were causally necessary. The causal relevance of the tool actions was highly visible in the transparent box condition, allowing the participants to potentially discriminate which actions were necessary. In contrast, the causal efficacy of the tool was hidden in the opaque box condition. When both the 23- and 30-month-olds were presented with either the transparent or opaque box, they were most commonly emulative rather than imitative, performing only the causally necessary actions. This strategy contrasts with the blanket imitation of both causally irrelevant and causally relevant actions witnessed at 3 and 5 years of age in our previous studies. The results challenge a current view of 1- and 2-year-olds as largely "blind imitators"; instead, they show that these young children have a variety of social learning processes available to them. More broadly the emerging patterns of results suggest, rather counterintuitively, that the human species becomes more imitative rather than less imitative with age, in some ways "mindlessly" so.
The successive contribution of brief daily conditioning sessions to the relatively long-term retention of stimulus-response interaction was assessed in 30 3-month-old infants. On each of 3 days, infants received a characteristic acquisition and extinction period, preceded by a 24-hr retention test. In addition to kick rate, duration of attention to a visual conjugate reinforcer (mobile) was measured. On the fourth day, the specificity of original learning was explored by exposing half the infants to a novel reinforcing agent while the remaining infants continued to view the original training mobile. Both kicks and attention significantly increased across successive retention tests for the first 3 days; on Day 4, infants viewing the novel mobile kicked significantly less and attended significantly longer than infants viewing the familiar mobile. Subsequent reattainment of high kick levels by the experimental group on Day 4 appeared to be highly individualistic and, in many instances, discontinuous.
This study investigated cognitive processes underlying tool use and knowledge transfer in 24-month-olds (N=123). Following a demonstration, participants chose a tool to reach a reward in a training transfer paradigm. Differing from previous research, various aspects considered to be relevant for children's performance were integrated within the same study design, and performance was examined on a trial-by-trial basis. More specifically, we analyzed how the following aspects affected toddlers' learning and transfer performance: causal information, degree of conflict between perceptually salient and functionally relevant information, and feedback information. Children with access to causal information outperformed children without corresponding information during the training and transfer phases. Perceptual conflict had a negative impact on transfer performance. However, children were quickly able to correct their choices based on feedback. Results are discussed in the light of recent accounts on tool use understanding.
Twenty-four Ss within 2 weeks of 24 months of age were presented a shapping procedure designed to lead to bidimensional sorting behavior. The shaping sequence involved three steps. Step I required spatial separation of two objects and 22 Ss reached criterial performance within the 25 trials allotted to this step. Step II required unidimensional sorting of two objects by color for half the Ss and by form for the other half. Ten Ss reached criterial performance within the 35 trials allotted to the second step. Step III required sorting three objects by both color and form. Four Ss succeeded on the third step at a level sufficient to reject statistically an existing hypothesis that children are limited to unidimensional attention prior to about 7 years of age. Success on Step III was significantly related to success on Step II. Errors on Step III were examined to further assess the unidimensional hypothesis and some support was found. Overall, however, data from this and other studies are viewed as more consistent with an alternative hypothesis that unidimensional and multidimensional attention are in part situationally dependent on the absence or presence of reinforcement for object discrimination.
The current study investigated the interaction of implicit grammatical gender and semantic category knowledge during object identification. German-learning toddlers (24-month-olds) were presented with picture pairs and heard a noun (without a preceding article) labeling one of the pictures. Labels for target and distracter images either matched or mismatched in grammatical gender and either matched or mismatched in semantic category. When target and distracter overlapped in both semantic and gender information, target recognition was impaired compared with when target and distracter overlapped on only one dimension. Results suggest that by 24 months of age, German-learning toddlers are already forming not only semantic but also grammatical gender categories and that these sources of information are activated, and interact, during object identification.
Sixteen college students who had been born totally blind, 16 who had been blinded totally at approximately 15 years of age, and 16 who had normal vision were asked to judge the similarities between color names. These judgments were submitted to the multidimensional scaling program INDSCAL. Like the sighted and the adventitiously blind, the congenitally blind yielded a 2-dimensional space in which the color terms formed a circle with the color names ordered in approximately the spectral sequence, red, orange, gold, yellow, green, turquoise, blue, purple, and violet, around the circumference. Contrary to previous research, the present findings suggest that knowledge of color relations can develop in the absence of first-hand experience with color perception.
Visual-perceptual, attentional, and visual-motor skills were examined in a group of 16 school-age children, born at 27-32 gestational weeks, who had performed normally on pediatric screening tests. Compared with 16 matched full-term controls, the preterms performed poorly on only two measures: they took longer to point to the missing arc of an annulus displayed on a computer screen and failed to find targets more often in a complex visual search task. They showed no deficits on tests of visual form extraction and closure. These data suggest that in the absence of any disability that is clinically detectable, prematurity results in a cluster of small but significant visual-motor impairments that persist into middle childhood. These relate to the maintenance of attention and visual-motor coordination, though visual form perception is not measurably affected. The results are discussed in the context of current neurobiological models of visual system organization.
The effect of pictures on the retention of novel words and prose passages was examined for both good and poor readers. The findings suggest that for both groups of subjects the presence of pictures enhances recall of the prose passages but has no effect on the recognition and pronunciation of novel words. Systematic differences in the strategies used by good and poor readers were also observed.
Four experiments are reported on exogenous (stimulus-driven) orienting in 3.5-month-old infants. A small moving bar embedded in a field of static bars was used to draw the infant's attention to one side of the display or the other. The bars could be either red or green. In all four of these experiments sensitivity to this small moving bar was affected significantly by how unevenly the red and green bars were distributed across the visual field. Sensitivity to the moving bar was lower when most of the red bars were in the field contralateral to this probe suggesting competition between the motion stimulus and contralaterally placed red but not green bars on a small, but significant proportion of trials. This basic effect replicated in four separate experiments and depended coarsely on how unevenly the red and the green bars were distributed across the field. A competition model of exogenous orienting with a winner-take-all rule captured the most important features of the data. The distribution of color within the visual field can bias attention significantly at 3.5 months making it either more or less likely that an infant will detect a moving stimulus.
Using a paired-comparison procedure, we examined the effect of familiarization variables on 3.5-month-old infants' (n = 120) retention of dynamic visual stimuli after 1-min, 1-day, and 1-month delays. The proportion of total looking time to the novel stimulus revealed novelty, null, and familiarity preferences after 1-min, 1-day, and 1-month delays, respectively, for infants who were permitted 30 s of familiarization time. Twenty seconds of familiarization time was insufficient to produce novelty preferences. These results support models of infant retention in which the direction of attentional preferences (novel, familiar, or null) depends on memory accessibility. To examine the impact of individual differences in familiarization or attentional style on memory, infants were identified as long or short lookers according to their peak-look duration on pretest and familiarization trial measures. Compared to long lookers, short lookers showed better retention over time indicating that much of the variability in the infant group data could be accounted for by these individual differences.
This investigation analyzed the methods used over the past 35 years to study emotion regulation (ER) in children. Articles published from 1975 through 2010 were identified in 42 child clinical, developmental, and emotion psychology journals. Overall, 61.1% of published ER articles relied on one method and 23.6% used two methods. Analyses revealed (a) 82.8% of published ER research occurring within the past decade; (b) higher rates of observational methods with infant and toddler/preschool samples, but more use of self-report methodology with middle childhood and adolescent samples; (c) a longer history of published ER research with samples of infants to 5-year-olds, including the use of more longitudinal design, compared with older samples; and (d) a positive association between journal impact ratings and the use of physiological and observational measurement. Review of the measurement tools used to capture ER revealed great diversity in how emotion processes are understood and evaluated.
ecent research in information processing has yielded evidence supporting the self-as-schema model with adults. Further self-schema research with depressed and nondepressed persons has suggested the existence of negative self-schemas in depression, lending support to a content-specificity self-schema model. The present studies were designed to investigate the applicability of the self-as-schema model to children and to examine the extent of negative self-schemas in relatively depressed children. A depth-of-processing incidental recall memory paradigm was employed with two groups of normal third- to sixth-grade children. Results supported the self-as-schema model as applied to children, even the youngest group, by indicating superior recall for words encoded under self-reference instructions, compared to semantic or structural orienting instructions. The content-specificity hypotheses were tested with relatively depressed and nondepressed children, and were supported only for the nondepressed children, who recalled mostly positive content words. The relatively depressed children did not demonstrate content specificity in their recall, showing a more "confused" pattern, and the results were discussed in terms of a developmental model of acquisition of depression vulnerability requiring repeated depressive experiences over time. Although the results were consistent with a self-schema approach, current controversies over the implications of depth-of-processing methods require further research to clarify mechanisms of enhanced self-reference recall.
Six experiments investigated how 4.5-month-old infants' perception of a display is affected by an immediate prior experience with an object similar to part of the test display. Prior research (A. Needham & R. Baillargeon, 1998) showed that when infants see an object alone and then see it next to a novel object, this prior experience allows them to determine the location of a boundary between the two objects. The present experiments investigated whether infants would also use an object similar, but not identical, to a test object in the same kind of task. The results indicate that infants' use of a prior experience is disrupted by changes in the features of the object, but not by a change in its spatial orientation. These findings suggest that, like adults, infants may expect that changes in the features of an object are associated with a change in the identity of the object, but do not have the same expectation for changes in spatial orientation.
The current study examined color constancy in infants using a familiarization paradigm. We first obtained isoluminance in each infant as defined by the minimum motion paradigm and used these data to control the luminance of stimuli in the main experiments. In the familiarization phase of the main experiment, two identical smiling face patterns were presented side by side in surrounding patches of various colors, presented on a computer-controlled display. The colors in the stimuli simulated the chromaticity of color chips (OSA uniform color scale) under a certain illuminant. The chromaticity of the whole pattern was changed to simulate illuminant color changes in the test phase except for one of the smiling face patterns that preserved its chromaticity and luminance. If infants had color constancy, they would perceive the face without any change in the chromaticity and luminance as a novel object surface and would show preference for it. Two types of illuminant changes were applied, from 6500 to 10,000K and from 6500 to 4500K, in correlated color temperature. The luminance contrast between the background and the face patterns remained constant across the illuminant changes. Our results showed that 4.5-month-old infants preferred the pattern that did not change its chromaticity under both types of illuminant color changes. This finding suggests that 4.5-month-olds may have color constancy under the strict control of luminance contrast.
The main purposes of this study were (a) to isolate monitoring of test performance from other forms of monitoring and (b) to determine the effect of taking a test on expectations about future performance. Children in grades 1-2, 4-5, and 7-8 were administered a vocabulary test. They either predicted their performance on tests like the one that was administered before taking the test, predicted after taking the test, or made postdictions about performance on the present test. There was unambiguous improvement in the accuracy of after-test predictions and postdictions compared to before-test predictions at grades 7-8 only. Although all age groups discriminated hard from easy items as they were doing them, such discrimination increased with age. In general, there were few sex differences, although whenever statistically significant sex differences in confidence were detected, boys tended to be more confident than girls. These results are consistent with claims that developmental changes in self-regulation could be tied to developmental changes in monitoring of performance and making predictions about future performance based on past performance.
The developmental control of operant motor responding (tapping response) by the verbal operants “faster” and “slower” was examined with 54 kindergarten and 30 first grade children. The effects of the verbal operants on motor behavior were assessed under three conditions: E verbalized the verbal operants; S said the verbal operants to themselves aloud; S whispered the verbal operants using only lip movements (approximating a covert condition). The major finding was an interaction between age and mode of delivery in controlling motor behavior. Kindergarten children's motor performance approximated first grade children when self-verbalizations were overt, but covert self-instructions had minimal functional control over motor behavior. First-grade children's self-verbalizations had more functional control over motor behavior when covert than overt. The results suggested a developmental sequence of the functional interaction between speech-for-self and nonverbal operants.
Two experiments (N=136) studied how 4- to 6-month-olds perceive a simple schematic event, seen as goal-directed action and reaction from 3 years of age. In our causal reaction event, a red square moved toward a blue square, stopping prior to contact. Blue began to move away before red stopped, so that both briefly moved simultaneously at a distance. Primarily, our study sought to determine from what age infants see the causal structure of this reaction event. In addition, we looked at whether this causal percept depends on an animate style of motion and whether it correlates with tasks assessing goal perception and goal-directed action. Infants saw either causal reactions or noncausal delayed control events in which blue started some time after red stopped. These events involved squares that moved either rigidly or nonrigidly in an apparently animate manner. After habituation to one of the four events, infants were tested on reversal of the habituation event. Spatiotemporal features reversed for all events, but causal roles changed only in reversed reactions. The 6-month-olds dishabituated significantly more to reversal of causal reaction events than to noncausal delay events, whereas younger infants reacted similarly to reversal of both. Thus, perceptual causality for reaction events emerges by 6 months of age, a younger age than previously reported but, crucially, the same age at which perceptual causality for launch events has emerged in prior research. On our second question, animate/inanimate motion had no effect at any age, nor did significant correlations emerge with our additional tasks assessing goal perception or goal-directed object retrieval. Available evidence, here and elsewhere, is as compatible with a view that infants initially see A affecting B, without differentiation into physical or psychological causality, as with the standard assumption of distinct physical/psychological causal perception.
Adults use eye contact as a cue to the mental and emotional states of others. Here, we examined developmental changes in the ability to discriminate between eye contact and averted gaze. Children (6-, 8-, 10-, and 14-year-olds) and adults (n=18/age) viewed photographs of a model fixating the center of a camera lens and a series of positions to the left/right or upward/downward and judged whether the model's gaze was direct or averted to the left/right or upward/downward. The horizontal range of fixation positions leading to the perception of direct gaze (the cone of gaze) was more than 50% larger in 6-year-olds than in adults, but it was adult-like and smaller than the vertical cone of gaze by 8 years of age. The vertical cone of gaze was large and statistically adult-like by age 6, with only a small linear reduction thereafter. In all age groups, the horizontal cone of gaze was centered on the bridge of the participant's nose and the vertical cone was centered slightly below the participant's eye height. These findings indicate that until after age 6, relatively poor sensitivity to direct versus averted gaze limits children's ability to use gaze cues to make social judgments.
Smith and colleagues (Smith, L. B., Thelen, E., Titzer, R., & McLin, D. (1999). Knowing in the context of acting: The task dynamics of the A-not-B error. Psychological Review, 106, 235-260) demonstrated that 10-month-olds succeed on a Piagetian AB search task if they are moved from a sitting position to a standing position between A and B trials. These authors explained this result by suggesting that because the reach must be executed by different muscle forces from the standing position, an appropriate reach to B is programmed without the memory of the previous reach interfering with the current reach. In the main study reported here, the influences of postural and spatial factors are separated by adding a condition in which the table containing the hiding wells is moved up at the same time as the infant is shifted to standing, thereby allowing a postural change without a change in the spatial relations between the hand and hiding locations. Results showed that in both a standard control condition and the sitting-to-standing condition in which the table also moved up, performance was poor. Only in the sitting-to-standing condition in which the spatial relation between the hand and apparatus was altered were infants successful. These outcomes demonstrate that perseveration effects are likely to occur at the level of reach planning rather than at the level of execution, thereby narrowing the gap between explanations of improvements in AB performance with age that emphasize prefrontal maturation as opposed to improvements in reaching ability.
Recent research on children's conceptual and procedural knowledge has suggested that there are individual differences in the ways that children combine these two types of knowledge across a number of mathematical topics. Cluster analyses have demonstrated that some children have more conceptual knowledge, some children have more procedural knowledge, and some children have an equal level of both. The current study investigated whether similar individual differences exist in children's understanding of fractions and searches for explanations for these differences. Grade 6 students (n=119) and Grade 8 students (n=114) were given measures of conceptual and procedural knowledge of fractions as well as measures of general fraction knowledge, general conceptual ability, and general procedural ability. Grade 6 children demonstrated a four-cluster solution reflecting those who do poorly on procedural and conceptual fraction knowledge, those who do well on both, those whose strength is procedural knowledge, and those whose strength is conceptual knowledge. Grade 8 children demonstrated a two-cluster solution reflecting those whose strength is procedural knowledge and those whose strength is conceptual knowledge. Cluster in either grade, however, did not vary in distribution across schools and was not related to general conceptual ability or general procedural ability. Overall, these results provide a more detailed picture of individual differences in conceptual and procedural knowledge in mathematical cognition.