Respective contributions of inhibition and knowledge levels in class inclusion development: a negative priming study

Dempster ( Dempster, 1995 ; Dempster & Corkill, 1999 ) proposed that developmental changes in performance on Piagetian tasks could be related to changes in inhibitory efficiency more than to logical development. In this study, the negative priming paradigm was adapted to the class inclusion task in order to investigate the role of inhibition and knowledge levels in the development of class inclusion. Participants were pre‐tested on two inclusion tasks, the standard Piagetian task and Markman's modification task, and assigned to different knowledge levels: empirical, and logical necessity. Children were then tested on a priming version of the class inclusion task. Results showed a negative priming effect, indicating that the irrelevant ‘subclass comparison strategy’ was actively inhibited during the processing of the class inclusion task. This effect was found to vary as a function of knowledge levels, indicating that the need for inhibition was reduced when children had attained logical necessity.     

Bodily maps of emotions across child development

Different basic emotions (anger, fear, disgust, happiness, sadness, and surprise) are consistently associated with distinct bodily sensation maps, which may underlie subjectively felt emotions. Here we investigated the development of bodily sensations associated with basic emotions in 6‐ to 17‐year‐old children and adolescents (n = 331). Children as young as 6 years of age associated statistically discernible, discrete patterns of bodily sensations with happiness, fear, and surprise, as well as with emotional neutrality. The bodily sensation maps changed from less to more specific, adult‐like patterns as a function of age. We conclude that emotion‐related bodily sensations become increasingly discrete over child development. Developing awareness of their emotion‐related bodily sensations may shape the way children perceive, label, and interpret emotions.     

Increasing convergence between imagined and executed movement across development: evidence for the emergence of movement representations

Motor imagery (MI) has become a principal focus of interest in studies on brain and behavior. However, changes in MI across development have received virtually no attention so far. In the present study, children (N = 112, 6 to 16 years old) performed a new, computerized Virtual Radial Fitts Task (VRFT) to determine their MI ability as well as the age‐related confluence between performance in executed and imagined movement conditions. Participants aimed at five targets, which were positioned along radial axes from a central target circle. The targets differed in width (2.5, 5, 10, 20 or 40 mm), resulting in an index of difficulty (ID) that varied from 6.9 to 2.9 bits. Performance was indexed by the linear relationship between ID and Movement Time (MT). The findings showed that executed task performance was slower than imagined performance. Moreover, conformance to Fitts’ Law during executed movement performance was obtained from a very young age. Most importantly, correlations between imagined and executed movements were low in the young participants but gradually increased across age. These age‐related changes in MI are hypothesized to reflect the children's emerging ability to represent internal models for prospective actions, consistent with the gradual unfolding of feedforward control processes.     

The race that precedes coactivation: development of multisensory facilitation in children

Rationale: The facilitating effect of multisensory integration on motor responses in adults is much larger than predicted by race‐models and is in accordance with the idea of coactivation. However, the development of multisensory facilitation of endogenously driven motor processes and its relationship to the development of complex cognitive skills in school‐age children is largely unexplored. Method: Twenty adults and 95 children where allocated into six age groups: 6, 7, 8, 9, 10–11 and adults. Participants’ motor reaction times (MRTs) and accuracy in response to the detection of auditory, visual and audiovisual stimuli were recorded. Children's reading accuracy and nonverbal IQ were also assessed. Results: In general, MRTs of children were significantly slower with greater variability than those of adults. Although the average level of multisensory facilitation was similar for all age groups, mean cumulative density functions (CDFs) showed that multisensory facilitation in 6 and 10–11‐year‐olds is within the predictive limits of race‐models. Where coactivation was seen in the CDF of individual children it was not as strong or as consistent as that in adults. The degree of multisensory facilitation did not correlate with age, reading accuracy or IQ. Conclusion: The average level of multisensory facilitation to endogenously driven motor responses does not change gradually with age nor is it related to intelligence or reading accuracy. In general, multisensory integration remains immature until 10–11 years of age and lies within the predicted confines of race‐models.     

Beliefs about the meaning and measurement of intelligence: a cross‐cultural comparison of American,British and Malaysian undergraduates

This study examined lay beliefs about intelligence cross‐culturally using a questionnaire based on an expert summary of what is known about intelligence. Two hundred and thirty five university undergraduates in Malaysia, 347 undergraduates in Britain and 137 undergraduates in the US rated for agreement 30 items about the nature, measurement, between‐group differences and practical importance of intelligence. An exploratory factor analysis revealed three factors: (1) stability, reliability and validity of intelligence tests; (2) practical importance of intelligence and (3) source and stability of within‐group intelligence. While the overall factor structure did not vary a great deal between groups, there were significant cross‐cultural differences on the mean scores for Factors 1–3. Explanations for cross‐cultural differences in implicit theories of intelligences are considered, and limitations of the study discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

The development of stranger fear in infancy and toddlerhood: normative development,individual differences,antecedents, and outcomes

Despite implications that stranger fear is an important aspect of developing behavioral inhibition, a known risk factor for anxiety, normative and atypical developmental trajectories of stranger fear across infancy and toddlerhood remain understudied. We used a large, longitudinal data set (N = 1285) including multi‐trait, multi‐method assessments of temperament to examine the normative course of development for stranger fear and to explore the possibility that individual differences exist in trajectories of stranger fear development between 6 and 36 months of age. A latent class growth analysis suggested four different trajectories of stranger fear during this period. Stable, high levels of stranger fear over time were associated with poorer RSA suppression at 6 months of age. Rates of concordance in trajectory‐based class membership for identical (monozygotic) and fraternal (dizygotic) twins, along with associations between atypical stranger fear development and greater anxiety‐related maternal characteristics, suggested that individual differences in developmental trajectories of stranger fear may be heritable. Importantly, trajectories of stranger fear during infancy and toddlerhood were linked to individual differences in behavioral inhibition, with chronically high levels of stranger fear and sharp increases in stranger fear over time related to greater levels of inhibition than other developmental trajectories.     

The dynamic lift of developmental process

What are the essential properties of human intelligence, currently unparalleled in its power relative to other biological forms and relative to artificial forms of intelligence? We suggest that answering this question depends critically on understanding developmental process. This paper considers three principles potentially essential to building human‐like intelligence: the heterogeneity of the component processes, the embedding of development in a social world, and developmental processes that change the cognitive system as a function of the history of soft‐assemblies of these heterogeneous processes in specific tasks. The paper uses examples from human development and from developmental robotics to show how these processes also may underlie biological intelligence and enable us to generate more advanced forms of artificial intelligence.     

Previous reward decreases errors of commission on later ‘No‐Go’ trials in children 4 to 12 years of age: evidence for a context monitoring account

Inhibitory control is widely hypothesized to be the cornerstone of executive function in childhood and the central deficit in a number of developmental disorders, including attention‐deficit/hyperactivity disorder (ADHD). However, recent evidence from adults indicates that performance on response inhibition tasks may primarily reflect non‐inhibitory attentional control (context monitoring) processes. Yet it may be that inhibition plays a more central role in childhood – a time when the architecture of cognitive processes might be more transparent due to wide variability in skill level. Here we directly test inhibitory and context monitoring explanations of task performance on a Go/No‐Go task in a large group of children 4–12 years of age. We conclude that traditional inhibitory conceptualizations of task performance on the Go/No‐Go task cannot account for our findings, calling into question evidence supporting a central role for inhibitory control in cognitive development or developmental psychopathology.     

Selective attention,filtering, and the development of working memory

Selective attention is fundamental for learning across many situations, yet it exhibits protracted development, with young children often failing to filter out distractors. In this research, we examine links between selective attention and working memory (WM) capacity across development. One possibility is that WM is resource‐limited, with development resulting in an increase in the amount of resources available for processing information. However, it is also possible that development results in greater efficiency of using available resources. In the current research, we explore the latter possibility by examining the developmental trajectory of selectivity and filtering in relation to WM capacity. We report that filtering efficiency of adults (N = 30), 7‐year‐olds (N = 29), and 4‐year‐olds (N = 28) was uniquely predictive of WM capacity. We also report that filtering efficiency continues to develop after 7 years of age, whereas WM capacity may reach an asymptote around 7 years of age. The latter finding suggests that selective attention plays a critical role in developmental and individual differences in visual working memory capacity.     

Concepts of intellect in relation to learning and adult development

This article is a summary and integration of results from studies of the organization and development of human abilities. Several kinds of results are interpreted as converging toward support of theories stipulating a hierarchy of intellectual functions. Near the top of this hierarchy, most related to intelligence as this is usually conceived, are the two broad sets of abilities known as fluid intelligence (Gf) and crystallized intelligence (Gc). The major focus of the review is on the decline of Gf through the “vital years of adulthood,” from 20 to 60 years of age. Major conclusions are:1. Sensory detector functions, near the bottom of the hierarchy of intellectual capacities, decline with development through the vital years, but this kind of decline is not responsible for aging decline of the major features of fluid intelligence: keenness of sensory function is not of the sine qua non of mature expressions of human intelligence.2. Memory abilities are somewhat higher in the hierarchy of intellectual functions, and thus are more strongly related to intelligence, than are sensory detectors. With increase in time interval over which retention is required, there is increase in the relationship of memory to Gf and to decline of Gf over the vital years. Accompanying this increase is an increase in the extent to which memory is dependent upon adequacy of organization at the stage of encoding. This, in turn, reflects the adequacy of eduction of relations and correlates, which is an essential feature of Gf.3. To the extent that very short-term memory is implicated in fluid intelligence, and the decline of this, it is intimately related to either a capacity or inclination to maintain close attention under conditions of high demand for attention.4. The speed with which one obtains correct answers to difficult problems is not closely related to the number of correct answers obtained when all subjects attempt all items in fluid intelligence tests, but clerical/perpetual speed, as indicated in tasks of quickly finding a particular symbol among others or tasks of making same/different judgments, is related to aging decline of Gf. As with short-term memory, this form of intellectual speediness appears to be closely related to capacities (or inclinations) for maintaining attention, dividing attention, and holding things in mind while doing other things.5. Crystallized intelligence probably increases over the vital years. This reflects dynamic restructuring of knowledge systems. It appears that there is not only an aging increase in knowledge but also an increase in the accessibility of information, a result being that humans become more creative (in one sense) as age increases through the vital years.6. Results from multivariate cross-sectional studies of intelligence are seen to be consistent with comparable results obtained with other kinds of research strategies.     

Neurocognitive development of relational reasoning

Relational reasoning is an essential component of fluid intelligence, and is known to have a protracted developmental trajectory. To date, little is known about the neural changes that underlie improvements in reasoning ability over development. In this event‐related functional magnetic resonance imaging (fMRI) study, children aged 8–12 and adults aged 18–25 performed a relational reasoning task adapted from Raven's Progressive Matrices. The task included three levels of relational reasoning demands: REL‐0, REL‐1, and REL‐2. Children exhibited disproportionately lower accuracy than adults on trials that required integration of two relations (REL‐2). Like adults, children engaged lateral prefrontal cortex (PFC) and parietal cortex during task performance; however, they exhibited different time courses and activation profiles, providing insight into their approach to the problems. As in prior studies, adults exhibited increased rostrolateral PFC (RLPFC) activation when relational integration was required (REL‐2 > REL‐1, REL‐0). Children also engaged RLPFC most strongly for REL‐2 problems at early stages of processing, but this differential activation relative to REL‐1 trials was not sustained throughout the trial. These results suggest that the children recruited RLPFC while processing relations, but failed to use it to integrate across two relations. Relational integration is critical for solving a variety of problems, and for appreciating analogies; the current findings suggest that developmental improvements in this function rely on changes in the profile of engagement of RLPFC, as well as dorsolateral PFC and parietal cortex.     

Categorical flexibility in preschoolers: contributions of conceptual knowledge and executive control

The current study evaluated the relative roles of conceptual knowledge and executive control on the development of categorical flexibility, the ability to switch between simultaneously available but conflicting categorical representations of an object. Experiment 1 assessed conceptual knowledge and executive control together; Experiment 2 differentiated conceptual knowledge from costly executive processes. In Experiment 1, 3‐ to 5‐year‐olds were given a three‐choice (taxonomic, thematic, and nonassociate) match‐to‐sample task and asked to match two associates. In Experiment 2, same‐aged children were assessed on another match‐to‐sample task that reduced executive costs by presenting thematic and taxonomic associates on separate trials. By comparing performance across tasks, age‐related changes resulting from conceptual knowledge and executive control indicated that conceptual knowledge of superordinate relations showed gains between 3 and 4 years, whereas gains in executive control were seen between 4 and 5 years, suggesting a décalage in the development of conceptual and executive processes underlying categorical flexibility.     

Validation of the multicultural personality questionnaire in the context of personnel selection

The present data provide support for the reliability of the Multicultural Personality Questionnaire among a sample of job applicants (n=264). Factor analysis confirmed five factors: Cultural Empathy, Open‐Mindedness, Social Initiative, Flexibility, and Emotional Stability. Moreover, the data largely support the construct validity of the MPQ. Correlations with the Big Five were in the expected direction, and as predicted, Cultural Empathy and Social Initiative were both positively related to socially oriented vocational interests and Flexibility to artistic interests. Against our predictions, Cultural Empathy, Open‐Mindedness, and Flexibility appeared to be related to verbal intelligence. A comparable pattern of relations of the Big Five with intelligence and vocational interests was found. Finally, the MPQ scales predicted variance in an indicator of overall behaviour above the Big Five, supporting its incremental validity. Copyright © 2003 John Wiley & Sons, Ltd.     

The development of change blindness: children's attentional priorities whilst viewing naturalistic scenes

Change blindness describes the surprising difficulty of detecting large changes in visual scenes when changes occur during a visual disruption. In order to study the developmental course of this phenomenon, a modified version of the flicker paradigm, based on Rensink, O’Regan & Clark (1997 ), was given to three groups of children aged 6–12 years and to a group of adults. This paradigm tested the ability to detect single colour, presence/absence and location changes of both high and low semantic importance in a complex scene. Semantically important changes were detected more quickly and accurately than less semantically important changes, by all age groups, indicating that children had the same attentional priorities as adults. Older children achieved more efficient and accurate detection of changes than younger children and reached almost adult level at 10–12 years old. These improvements parallel age‐related developments in attention and visual perception.     

The development of executive function in early childhood is inversely related to change in body mass index: Evidence for an energetic tradeoff?

A well‐established literature demonstrates executive function (EF) deficits in obese children and adults relative to healthy weight comparisons. EF deficits in obesity are associated with overeating and impulsive consumption of high calorie foods leading to excess weight gain and to problems with metabolic regulation and low‐grade inflammation that detrimentally affect the structure and function of prefrontal cortex. Here, we test a complementary explanation for the relation between EF and body mass index (BMI) grounded in the energy demand of the developing brain. Recent work shows that the brain accounts for a lifetime peak of 66% of resting metabolic rate in childhood and that developmental changes in brain energetics and normative changes in body weight gain are closely inversely related. This finding suggests a trade‐off in early childhood between energy used to support brain development versus energy used to support physical growth and fat deposition. To test this theorized energetic trade‐off, we analyzed data from a large longitudinal sample (N = 1,292) and found that change in EF from age 3 to 5 years, as a proxy for brain development in energetically costly prefrontal cortex, is inversely related to change in BMI from age 2 to 5 years. Greater linear decline in BMI predicted greater linear increase in EF. We interpret this finding as tentative support for a brain–body energetic trade‐off in early childhood with implications for lifetime obesity risk.     

The influence of pubertal maturation on antisaccade performance

Adolescence is a period characterized by continued improvements in inhibitory control, and this persisting immaturity is believed to interact with affective/motivational behavior to generate the impulsive and risk‐taking behavior evidenced at this time. Puberty is a central event of adolescence that has been shown to influence affective/motivational behavior. However, despite plausible mechanisms by which puberty might influence inhibitory control, researchers have yet to test this possibility rigorously. Thus, we designed a study to examine the unique role of pubertal maturation, independent of age, in the development of inhibitory control. In order to minimize age‐related variability while maximizing pubertal status variability, we recruited 78 participants (34 F) whose ages narrowly spanned the mean age of gonadarche for each sex (F: ages 11–13, M: ages 12–14). Two complementary measures were used to assess pubertal status: (1) circulating blood serum testosterone and estradiol levels reflecting internal manifestations of pubertal maturation, and (2) Tanner staging by a trained nurse reflecting pubertal maturation's external manifestations. Inhibitory control was assessed using the antisaccade task, and findings were adjusted for the potential effect of age. Results revealed no association between testosterone levels and error rates or response latencies in either sex. In girls, estradiol levels were not associated with error rates, but were associated with faster response latencies. There was similarly no association between Tanner status and error rates, although girls in more advanced pubertal stages showed faster response latencies. Power analyses indicate that findings of a lack of association did not reflect limited statistical power. Thus, in a study designed to isolate the effects of pubertal maturation independent of age, both external and internal indices of pubertal maturation converged to indicate that age‐related improvements in cold antisaccade performance are independent of pubertal maturation.     

Response inhibition and interference control: Effects of schizophrenia,genetic risk,and schizotypy

The ability to inhibit inappropriate responses and suppress irrelevant information is a core feature of executive control. In this study, we provide a detailed analysis of prepotent response inhibition and interference in patients with schizophrenia. To further test the role of genetic factors and subclinical schizophrenia‐like traits, we additionally studied clinically unaffected, first‐degree relatives of schizophrenia patients and assessed dimensions of schizotypy in both relatives and healthy controls. Inhibition and interference control were assessed using a battery comprising the antisaccade, Stroop, stop signal, go/no‐go, flanker, and Simon tasks. Schizophrenia patients differed from both relatives and controls in making more errors on the antisaccade task and having longer response times on the Stroop task, especially the incongruent condition. Patients also had general, that is, condition independent, increases in reaction times on the go/no‐go and flanker tasks and made more errors on the flanker and Simon tasks, suggesting general performance impairments independent of inhibitory demand. Relatives were characterized by hypometric antisaccade amplitude gain despite normal prosaccades, suggesting a selective deficit in non‐standard sensorimotor transformations. Schizotypy was correlated with inhibitory performance across a number of tasks in both relatives and controls. Generally, these effects were independent of verbal intelligence levels. Overall, the findings point to rather selective impairments of inhibitory control in the schizophrenia spectrum and confirm a previously observed deficit in antisaccade spatial accuracy as an endophenotype of schizophrenia.     

The development of bodily self‐consciousness: changing responses to the Full Body Illusion in childhood

The present work investigates the development of bodily self‐consciousness and its relation to multisensory bodily information, by measuring for the first time the development of responses to the full body illusion in childhood. We tested three age groups of children: 6‐ to 7‐year‐olds (n = 28); 8‐ to 9‐year‐olds (n = 21); 10‐ to 11‐year‐olds (n = 19), and a group of adults (n = 31). Each participant wore a head‐mounted display (HMD) which displayed a view from a video camera positioned 2 metres behind their own back. Thus, they could view a virtual body from behind. We manipulated visuo‐tactile synchrony by showing the participants a view of their virtual back being stroked with a stick at the same time and same place as their real back (synchronous condition), or at different times and places (asynchronous condition). After each period of stroking, we measured three aspects of bodily self‐consciousness: drift in perceived self‐location, self‐identification with the virtual body, and touch referral to the virtual body. Results show that self‐identification with the virtual body was significantly stronger in the synchronous condition than in the asynchronous condition even in the youngest group tested; however, the size of this effect increased with age. Touch referral to the virtual body was greater in the synchronous condition than in the asynchronous condition only for 10‐ to 11‐year‐olds and adults. Drift in perceived self‐location was greater in the synchronous condition than in the asynchronous condition only for adults. Thus, the youngest age tested can self‐identify with a virtual body, but the links between multisensory signals and bodily self‐consciousness develop significantly across childhood. This suggests a long period of development of the bodily self and exciting potential for the use of virtual reality technologies with children.     

When Stronger Knowledge Slows You Down: Semantic Relatedness Predicts Children's Co‐Activation of Related Items in a Visual Search Paradigm

A large literature suggests that the organization of words in semantic memory, reflecting meaningful relations among words and the concepts to which they refer, supports many cognitive processes, including memory encoding and retrieval, word learning, and inferential reasoning. The co‐activation of related items has been proposed as a mechanism by which semantic knowledge influences cognition, and contemporary accounts of semantic knowledge propose that this co‐activation is graded—that it depends on how strongly related the items are in semantic memory. Prior research with adults yielded evidence supporting this prediction; however, there is currently no evidence of graded co‐activation early in development. This study provides the first evidence that in children the co‐activation of related items depends on their relational strength in semantic memory. Participants (N = 84, age range: 3–9 years) were asked to identify a target (e.g., bone) amid distractors. Children's responses were slowed down by the presence of a related distractor (e.g., puppy) relative to unrelated distractors (e.g., flower)—suggesting that children co‐activated related items upon hearing the name of the target. Importantly, the degree of this co‐activation was predicted by the strength of the target–distractor relation, such that distractors more strongly related to the targets slowed down children to a larger extent. These findings have important implications for understanding how organized semantic knowledge affects other cognitive processes across development.     

The development of creative cognition across adolescence: distinct trajectories for insight and divergent thinking

We examined developmental trajectories of creative cognition across adolescence. Participants (N = 98), divided into four age groups (12/13 yrs, 15/16 yrs, 18/19 yrs, and 25–30 yrs), were subjected to a battery of tasks gauging creative insight (visual; verbal) and divergent thinking (verbal; visuo‐spatial). The two older age groups outperformed the two younger age groups on insight tasks. The 25–30‐year‐olds outperformed the two youngest age groups on the originality measure of verbal divergent thinking. No age‐group differences were observed for verbal divergent thinking fluency and flexibility. On divergent thinking in the visuo‐spatial domain, however, only 15/16‐year‐olds outperformed 12/13‐year‐olds; a model with peak performance for 15/16‐years‐old showed the best fit. The results for the different creativity processes are discussed in relation to cognitive and related neurobiological models. We conclude that mid‐adolescence is a period of not only immaturities but also of creative potentials in the visuo‐spatial domain, possibly related to developing control functions and explorative behavior.