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Genetic syndrome groups at high risk of autism comorbidity, like Down syndrome and fragile X syndrome, have been presented as useful models for understanding risk and protective factors involved in the emergence of autistic traits. Yet despite reaching clinical thresholds, these ‘syndromic’ forms of autism appear to differ in significant ways from the idiopathic or ‘non-syndromic’ autism profile. We explore alternative mechanistic explanations for these differences and propose a developmental interpretation of syndromic autism that takes into account the character of the genetic disorder. This interpretation anticipates syndrome-specific autism phenotypes, since the neurocognitive and behavioural expression of the autism is coloured by syndromically defined atypicalities. To uncover the true nature of comorbidities and of autism per se, we argue that it is key to extend definitions of autism to include the perceptual and neurocognitive characteristics of the disorder and then apply this multilevel conceptualisation to the study of syndromic autism profiles.

Genetic mutations and environmental factors dynamically influence gene expression and developmental trajectories at the neural, cognitive, and behavioral levels. The examples in this article cover different periods of neurocognitive development—early childhood, adolescence, and adulthood—and focus on studies in which researchers have used a variety of methodologies to illustrate the early effects of socioeconomic status and stress on brain function, as well as how allelic differences explain why some individuals respond to intervention and others do not. These studies highlight how similar behaviors can be driven by different underlying neural processes and show how a neurocomputational model of early development can account for neurodevelopmental syndromes, such as autism spectrum disorders, with novel implications for intervention. Finally, these studies illustrate the importance of the timing of environmental and genetic factors on development, consistent with our view that phenotypes are emergent, not predetermined.

AbstractDevelopmental trajectories of autism spectrum disorder (ASD) or attention deficit and hyperactivity disorder (ADHD) comorbidity in genetically determined neurodevelopmental disorders are not well understood. The objective of the current longitudinal study was to explore symptomology and comorbidity in boys with fragile X syndrome focusing on their profiles of autistic and inattentive behaviours in performance on the Leiter R Performance Scale, a non-verbal IQ measure. Of the 46 children, 10 were classified as having combined ASD and ADHD symptoms, 14 met the criterion for autism alone, 10 met the criterion for ADHD alone, and 12 had no symptoms for either. Results indicated that changes in cognitive profiles over time were similar for all groups and there was a slight improvement in growth scores suggesting developmental change. In terms of ASD and ADHD symptomology, we also found stable differences across groups over time. Collectively, these findings highlight the pressing need to explore symptomology longitudinally across disorders at high risk from comorbid ASD and ADHD diagnoses.

This article identifies an increasing change from rather static approaches to neurodevelopmental disorders and the search for ‘intact’ and ‘impaired’ domain-specific modules, to more recent dynamic perspectives that take account of cross-domain interactions and changes over developmental time.

Grouping by luminance and shape similarity has previously been demonstrated in neonates and at 4 months, respectively. By contrast, grouping by proximity has hitherto not been investigated in infancy. This is also the first study to chart the developmental emergence of perceptual grouping longitudinally. Sixty-one infants were presented with a matrix of local stimuli grouped horizontally or vertically by luminance, shape or proximity at 2, 4, and 6 months. Infants were exposed to each set of stimuli for three presentation durations. Grouping was demonstrated for luminance similarity at the earliest testing age, 2 months, by shape similarity at 4 months, but was not observed for grouping by proximity. Grouping by shape similarity showed a distinctive pattern of grouping ability across exposure durations, which reflected familiarity preferences followed by novelty preferences. This remained stable across age. No link was found between the emergence of perceptual grouping ability and the exposure duration required to elicit grouping. We conclude by stressing the importance of longitudinal studies of infant development in furthering our understanding of human cognition, rather than relying on assumptions from the adult endstate.

Perceptual grouping by luminance similarity and by proximity was investigated in infants with Williams syndrome (WS) aged between 6 and 36 months (visit 1, N=29). WS infants who were still under 36 months old, 8 months later, repeated the testing procedure (visit 2, N=15). Performance was compared to typically developing (TD) infants aged from 2 to 20 months (N=63). Consistent with the literature, TD participants showed grouping by luminance at the youngest testing age, 2 months. Grouping by proximity had not previous been charted in typical development: this study showed grouping by proximity at 8 months. Infants with WS could group by luminance. Developmental progression of the WS group showed some similarities to typical development, although further investigation is required to further address this in more depth. In contrast, infants with WS were not able to group by proximity. This pattern of emergence and development of grouping abilities is considered in relation to the pattern of grouping abilities observed in adults with WS.

Despite the fact that developmental impairments of number skills are common, they remain sparsely investigated. We explored low-level numerical representations and their developmental trajectory in a developmental disorder, Williams syndrome (WS). Groups of WS and typically developing (TD) individuals estimated rapidly-presented arrays of 5, 7, 9, and 11 dots. In comparison to the normal developmental trajectory, the ontogenesis of estimation skills in WS is both delayed and deviant. Whereas TD children's estimations became significantly more accurate and less variable over developmental time, only marginal developmental changes in estimation ability emerged across age in the WS groups. Our data highlight the importance of considering developmental changes in low-level components of numerical cognition in atypical development while at the same time emphasizing the importance of paying closer attention to quantitative changes and their functional role in typical development.

This paper maintains that studies of atypical attention targeting one particular age group are unlikely to be informative of syndrome-specific deficits and their developmental changes. We propose a new approach to the study of attentional deficits in genetic disorders, arguing for tracing cross-syndrome developmental trajectories from infancy through childhood to adulthood. Few studies have incorporated a developmental approach to determine whether the pattern of deficits and proficiencies remains constant across developmental time. Fewer still have included a cross-syndrome perspective to address these issues. Focusing on the cognitive domain of attention and its component parts, and using a cross-syndrome developmental perspective, the present set of studies compared the trajectories of different aspects of attention in three developmental disorders: Fragile X syndrome (FXS), Down syndrome (DS) and Williams syndrome (WS). Hitherto, these syndromes have all been reported as displaying serious “attentional deficits” above those expected in the general population. We predicted that, when one considers in greater detail subcomponent processes of attention, then ostensibly common difficulties do not necessarily emerge from common developmental pathways. We addressed this question with two studies. The first focused on inhibitory control, orienting and selective attention in infants and toddlers, and the second concentrated on selective attention, sustained attention and inhibitory control in mid-late childhood. The current results and their integration with earlier findings in adults point both to commonalities and to important syndrome-specific differences in attentional component processes, questioning whether profiles remain constant across developmental time.

Perceptual grouping by luminance similarity and by proximity was investigated in infants with Williams syndrome (WS) aged between 6 and 36 months (visit 1, N=29). WS infants who were still under 36 months old, 8 months later, repeated the testing procedure (visit 2, N=15). Performance was compared to typically developing (TD) infants aged from 2 to 20 months (N=63). Consistent with the literature, TD participants showed grouping by luminance at the youngest testing age, 2 months. Grouping by proximity had not previous been charted in typical development: this study showed grouping by proximity at 8 months. Infants with WS could group by luminance. Developmental progression of the WS group showed some similarities to typical development, although further investigation is required to further address this in more depth. In contrast, infants with WS were not able to group by proximity. This pattern of emergence and development of grouping abilities is considered in relation to the pattern of grouping abilities observed in adults with WS.

Abstract: In their excitement at using the human genome project to uncover the functions of specific genes, researchers have often ignored one fundamental factor: the gradual process of ontogenetic development. The view that there might be a gene for spatial cognition or language has emanated from a focus on the structure of the adult brain in neuropsychological patients whose brains were fully and normally developed until their brain insult. The developing brain is very different. It starts out highly interconnected across regions and is neither localized nor specialized at birth, allowing interaction with the environment to play an important role in gene expression and the ultimate cognitive phenotype. This article takes a neuro constructivist perspective, arguing that domain-specific end states can stem from more domain-general start states, that associations may turn out to be as informative as dissociations, and that genetic mutations that alter the trajectory of ontogenetic development can inform nature/nurture debates.

It has been claimed that verbal short-term memory in Williams syndrome is characterised by an over-use of phonological coding alongside a reduced contribution of lexical semantics. We critically examine this hypothesis and present results from a memory span task comparing performance on concrete and abstract words, together with a replication of a span task using phonologically similar and phonologically dissimilar words. Fourteen participants with Williams syndrome were individually matched to two groups of typically developing children. The first control group was matched on digit span and the second on vocabulary level. Significant effects were found for both the semantic and the phonological variables in the WS group as well as in the control groups, with no interaction between experimental variable and group in either experiment. The results demonstrate that, despite claims to the contrary, children and adults with WS are able to access and make use of lexical semantics in a verbal short-term memory task in a manner comparable to typically developing individuals.

Individuals with Williams syndrome show an unusual neuropsychological profile, with relatively strong language abilities and impoverished visual and spatial abilities. Two studies are reported that examine the interaction between these two domains in Williams syndrome by assessing individuals' comprehension of spoken language with a spatial component. In a first study, the Test for Reception of Grammar (Bishop, 1983) was given to 32 individuals with Williams syndrome and to controls matched individually for total number of errors on the task. Individuals with Williams syndrome had particular problems when asked to comprehend sentences containing spatial prepositions, making significantly more errors on these items than control groups. A second study examined in more detail comprehension of sentences with spatial and non-spatial components, comparing the performance of 15 individuals with Williams syndrome and control groups matched for vocabulary ability. Individuals with Williams syndrome again showed impaired comprehension of spoken spatial terms. In contrast, they were unimpaired in comprehending utterances without a spatial component, with the exception of descriptions testing comprehension of non-spatial comparatives (lighter than and darker than). These results suggest that the spatial difficulties experienced by individuals with Williams syndrome may constrain language comprehension in certain circumstances. They also shed light on the ways in which spatial cognition may interact with language comprehension more generally.

The uneven cognitive phenotype in the adult outcome of Williams syndrome has led some researchers to make strong claims about the modularity of the brain and the purported genetically determined, innate specification of cognitive modules. Such arguments have particularly been marshaled with respect to language. We challenge this direct generalization from adult phenotypic outcomes to genetic specification and consider instead how genetic disorders provide clues to the constraints on plasticity that shape the outcome of development. We specifically examine behavioral studies, brain imaging, and computational modeling of language in Williams syndrome but contend that our theoretical arguments apply equally to other cognitive domains and other developmental disorders. While acknowledging that selective deficits in normal adult patients might justify claims about cognitive modularity, we question whether similar, seemingly selective deficits found in genetic disorders can be used to argue that such cognitive modules are prespecified in infant brains. Cognitive modules are, in our view, the outcome of development, not its starting point. We note that most work on genetic disorders ignores one vital factor, the actual process of ontogenetic development, and argue that it is vital to view genetic disorders as proceeding under different neurocomputational constraints, not as demonstrations of static modularity.

Williams syndrome is a genetic disorder in which visuo-spatial performance is poor. Theorists have claimed that the deficit lies in high-level processing, leaving low-level visual processes intact. We investigated this claim by examining an aspect of low-level processing, perceptual completion, i.e. the ability of this clinical group to perceive illusory Kanizsa squares. We then used event-related potentials to examine neural correlates of perceptual completion. While participants were able to perceive illusory contours, the neural correlates of this apparently normal perception were different from controls. Such differences in low-level visual processes may significantly impact on the development of higher-level visual processes. We conclude that, contrary to earlier claims, there is atypical neural processing during low-level visual perception in Williams syndrome.

AbstractWe obtained 31P magnetic resonance spectra from the brains in vivo of 101 males (range 6–72 years). In addition, cognitive test data were obtained from 42 boys (6–13 years) and from 26 adult males (22–56 years) of this test group. Significant correlations were observed in both adults and children between various inorganic phosphate (Pi)-containing 31P peak ratios [e.g. Pi/adenosine triphosphate (ATP)] and (predominantly verbal) cognitive tasks. No change in the Pi/ATP ratio was observed across the age range studied. Brain pH was shown to decrease significantly with age in a relationship best described by a decaying exponential. This indicated that brain pH does not stabilize at adult values until at least the late teens. We explored the possibility of a relationship between brain pH and neuronal density. In particular, we noted that our previous observation of a relationship between pH and IQ in children was not readily detected in the adult populations, whereas phosphorus metabolite ratios (in particular, those containing Pi) were found to correlate with (predominantly verbal) cognitive task performance in both adults and children. We assessed how these observations may be interpreted in the context of a metabolic vs. histological debate.Copyright © 2003 S. Karger AG, Basel

We obtained 31P magnetic resonance spectra from the brains in vivo of 101 males (range 6–72 years). In addition, cognitive test data were obtained from 42 boys (6–13 years) and from 26 adult males (22–56 years) of this test group. Significant correlations were observed in both adults and children between various inorganic phosphate (Pi)-containing 31P peak ratios [e.g. Pi/adenosine triphosphate (ATP)] and (predominantly verbal) cognitive tasks. No change in the Pi/ATP ratio was observed across the age range studied. Brain pH was shown to decrease significantly with age in a relationship best described by a decaying exponential. This indicated that brain pH does not stabilize at adult values until at least the late teens. We explored the possibility of a relationship between brain pH and neuronal density. In particular, we noted that our previous observation of a relationship between pH and IQ in children was not readily detected in the adult populations, whereas phosphorus metabolite ratios (in particular, those containing Pi) were found to correlate with (predominantly verbal) cognitive task performance in both adults and children. We assessed how these observations may be interpreted in the context of a metabolic vs. histological debate.

To date, research involving functional neuroimaging of typical and atypical development has depended on several assumptions about the postnatal maturation of the brain. We consider evidence from multiple levels of analysis that brings into question these underlying assumptions and advance an alternative view. This alternative view, based on an “interactive specialization” approach to postnatal brain development, indicates that there is a need to: obtain data from early in development; focus more on differences in interregional interactions rather than searching for localized, discrete lesions; examine the temporal dynamics of neural processing; and move away from deficits to image tasks in which atypical participants perform as well as typically developing participants.

The present study investigated whether 2- to 6-year-old children with Williams syndrome can form new object categories based on either visual or verbal information alone. Children were presented with six triads of objects. In each triad, two objects either shared visual properties, or were given the same name. Following the presentation of each triad, categorization based on the shared visual or verbal property was evaluated through object manipulation. While the children categorized the objects according to visual cues, they failed to use the verbal cues. These results contrast with previous research showing that typically developing toddlers, who were much younger than the children with Williams syndrome and much less advanced in their vocabulary development, could perform both types of categorization. The present study hence supports the claim that vocabulary acquisition in Williams syndrome develops atypically.

Two developmental disorders, autism and Williams syndrome, are both commonly described as having difficulties in integrating perceptual features, i.e. binding spatially separate elements into a whole. It is already known that healthy adults and infants display electroencephalographic (EEG) γ-band bursts (around 40 Hz) when the brain is required to achieve such binding. Here we explore γ-band EEG in autism and Williams Syndrome and demonstrate differential abnormalities in the two phenotypes. We show that despite putative processing similarities at the cognitive level, binding in Williams syndrome and autism can be dissociated at the neurophysiological level by different abnormalities in underlying brain oscillatory activity. Our study is the first to identify that binding-related γ EEG can be disordered in humans.

Williams syndrome, due to a contiguous gene deletion at 7q11.23, is associated with a distinctive facial appearance, cardiac abnormalities, infantile hypercalcemia, and growth and developmental retardation. The deletion is approximately 1.5Mb and includes ~17 genes. Large repeats containing genes and pseudogenes flank the deletion breakpoints, and the mutation mechanism commonly appears to be unequal meiotic recombination. Elastin hemizygosity is associated with supravalvular aortic stenosis and other vascular stenoses. LIM Kinase 1 hemizygosity may contribute to the characteristic cognitive profile. The relationship of the other deleted genes to phenotypic features is not known. People with Williams syndrome tend to be over friendly—though anxious—and lack social judgement skills. They exhibit an uneven cognitive–linguistic profile together with mild to severe mental retardation. Analysis of the cognitive phenotype based on analyses of the mental processes underlying overt behavior demonstrates major differences between normal and WS subjects although for some areas, such as face processing, WS subjects can achieve near normal scores. Cognitive analysis of patients with small deletions in 7q11.23 which include elastin and LIM Kinase 1 have revealed varying results and it is premature to draw genotype–phenotype correlations. Am. J. Med. Genet. (Semin. Med. Genet.) 97:164–171, 2000. © 2000 Wiley-Liss, Inc.

This study concerns children's use of cohesive devices in discourse production. A distinction is drawn between 'coherence', the focus of work by story grammarians, and 'cohesion', a more strictly linguistic problem which holds for narrative and non-narrative discourse. The analysis not only covers changes in surface output, but focuses on underlying representations with respect to changes in the organization of linguistic entries in memory outside input-output relations, changes in the internal processes which constrain production of discourse during input-output relations, and the relationship between these two aspects of the development of cohesion.

Williams syndrome, a neurodevelopmental disorder, has attracted a great deal of debate concerning the purported intactness of language in the face of other serious cognitive deficits. As more in-depth studies of specific aspects of WS language have emerged, the notion of a preserved language module has been seriously challenged. Although WS vocabulary scores are often impressive, several investigators have claimed that WS semantics are aberrant. All studies hitherto have been based on off-line experiments which necessarily involve metalinguistic processes. This clearly affects the performance of individuals with cognitive deficits. We report here an on-line study probing the semantic structure of the WS lexicon, using a task — semantic priming — which minimises metalinguistic demands. We show that WS subjects display the same taxonomic/category and thematic/functional priming effects as normal controls. The results are discussed in terms of the differences between receptive and expressive language, as well as the fact that although semantic memory and the automatic access to semantic information for individual words is normal in WS, the integration of semantic information into sentence comprehension may be abnormal. The importance of online tasks to highlight such differences is stressed.

It is argued that the static adult neuropsychological model is inappropriate for explaining the development of many atypical children whose brains cannot be considered in terms of a normal brain with parts intact and parts impaired. Rather, their brains develop differently from normal children from the very outset. I illustrate this with two examples from Williams syndrome, showing how equivalent behavioral outcomes stem from different underlying processes.

This is an original, important and stimulating book, which attempts a Hegelian synthesis of Piagetian constructivism and Fodorian modularity in terms of the author's own model of 'representational redescription.* As this is an unfairly abstract way of characterising what is a refreshingly lucid work, I will attempt to make its claims both simple and clear. I will first outline Fodor's modularity hypothesis, contrasting it with Piaget's constructivism; I will then summarise K-S's original contribution, borrowing some of her more elegant examples; and I will conclude by discussing areas where I think her arguments fail, paying particular attention to the nature and development of knowledge of language.

To determine what biochemical changes may occur in the brain in Williams syndrome (WS) and whether these changes may be related to the cognitive deficits.

Ervin-Tripp, S. and Mitchell-Kernan, E. (Eds). Child Discourse. New York: Academic Press. 1977. Pp. 266. £6.75. ISBN 0 12 241950 2.Hulse, S. H. Fowler, H. and Honig, W. K. Cognitive, Processes in Animal Behaviour. Hillsdale, N.J.: Erlbaum Associates. 1978. Pp. 465. £21.00. ISBN 0 470 26484 5.Wasserman, G. S. Color Vision: An Historical Introduction. New York: J. Wiley. 1978. Pp. xv & 224. $18.95/£13.40. ISBN 0 471 92128 9.Amsterdum Studies in the Theory and History of Linguistic Science II: Classics in Psycholinguistics. Amsterdam: John Benjamins. 1978.Vol. I. Thumb, A. and Marbe, K. Experimentelle Untersuchungen über die psychologische Grundlagen der Sprachlichen Analogiebildung. Murray, D. J. (Ed.). Pp. 108. Hfl. 45. ISBN 90 272 0972 3.vol. II. Meringer, R. and Mayer, C. Versprechen und verlesen. Fay, D. and Cutler, A. (Eds). Pp. 207. Hfl. 60. ISBN 90 272 0973 1.Drury, C. G. and Fox, J. G. Human Reliability in Quality Control. London: Taylor & Francis. 1975. Pp. 315. £7.00. ISBN 0 85066 088 2.Weber, E. H. The Sense of Touch. De Tactu. Translated by H. E. Ross. Der Tastsinn-Translated by D. J. Murray. London: Academic Press. 1978. Pp. x+278. £7.40. ISBN 0 12 740550 X.Carterette, E. C. and Friedman, M. P. (Eds). Handbook of Perception, Vol. V. Seeing. New York: Academic Press. 1975. Pp. 527. £13.70. ISBN 0 12 161905 2.Evans, E. E. and Wilson, J. P. London: Psychophysics and Physiology of Hearing. Academic Press. 1977. Pp. 525. £14.00. ISBN 0 12 244050 1.Flavell, J. H. Cognitive Development. Englewood Cliffs, N. J.: Prentice Hall. 1977. Pp. 286. $6.95. ISBN 0 13 139774 5.Achenbach, T. M. Research in Developmental Psychology: Concepts, Strategies, Methods. New York: The Free Press. 1978. Pp. 350. $14.95. ISBN 0 02 900180 3.Carlson, N. R. Physiology of Behavior. Boston: Allyn & Bacon. 1977. Pp. 672. Hardback £13.60; softback £6.96. ISBN 795930.Standish, L. J. A Workbook for Physiology of Behavior by N. R. Carlson. Boston: Allyn & Bacon. 1977. Pp. 318. £3.95. ISBN 0 205 05758 6.Silverman, P. Animal Behaviour in the Laboratory. London: Chapman and Hall, 1978. Pp. xii+409. £15.00. ISBN 0 412 14800 5.Gulick, W. L. and Lawson, R. B. Human Stereopsis: A Psychophysical Approach. New York: Oxford University Press. 1976. Pp. 292. £11.75. ISBN 0 19 501971 7.Spear, N. E. The Processing of Memories: Forgetting and Retention. Hillsdale, N.J.: Erlbaum Associates. 1978. Pp. 553. £21.15. ISBN 0 470 26290 7.Kinsboufwe, M. (Ed.). Asymmetrical Function of the Human Brain. Cambridge University Press, 1978. Pp. x+581. £18.00. ISBN 0 521 24181 5.Ryall, R. W. Mechanisms of Drug Action on the Nervous System. London: Cambridge University Press. 1979. Pp. 144. Hardback £9.00; paperback £2.50. ISBN 0 521 2215 0.Gregson, R. A. M. Psychometrics of Similarity. New York: Academic Press. 1975. Pp. 255. £10.30. ISBN 0 12 301550 2.de Potter, J.-C. (Ed.). Psychomotor Learning. Brussels: Editions de l'Universite de Bruxelles. 1978. Pp. 306. 600 FB. ISBN 2 8004 0663 1.

Sólo los seres humanos utilizan herramientas para dejar trazas permanentes de sus actos comunicativos. Esta capacidad notacional se manifiesta en distintos sistemas notacionales: dibujo, escritura o notación numérica que se distinguen entre sí por sus elementos, por sus regularidades combinatorias y por cumplir distintas funciones. En este trabajo exploramos cómo comprenden los niños entre 3:8 y 6:6 años de edad las relaciones entre sistemas utilizando dos situaciones de producción de notaciones. En la primera los niños debían escribir qué y cuántos objetos aparecen dibujados en una serie de tarjetas. El objeto de esta situación fue verificar sus posibilidades de producir notaciones diferenciadas según las restricciones formales y adecuadas a las funciones específicas de cada sistema. En la segunda, los niños debían inventar letras, números y palabras que no existen. El propósito fue averiguar en qué medida las restricciones formales y la adecuación funcional que hubieran demostrado en la primera situación estaban implícitas en sus procedimientos de producción o podían ser internamente explicitadas, y por tanto transgredidas. Los resultados demuestran que desde muy temprana edad los niños producen notaciones diferenciadas según las restricciones formales propias de la escritura y del sistema de notación numérico. Sin embargo, la diferenciación formal no asegura el uso adecuado de las notaciones para sus funciones específicas. A pesar del conocimiento de las restricciones formales de cada sistema, algunos niños recurren al dibujo para indicar qué objetos hay en una figura o a la escritura para indicar cuántos objetos hay. Sólo cuando el conocimiento de las restricciones formales que estaba implícito en los procedimientos de producción se explicita internamente, y puede por tanto ser transgredido, el niño utiliza cada sistema según su función específica.

La conciencia metalingüística (“metalinguistic awareness”) puede incluirse en el desarrollo metacognitivo en general. Aunque se ha establecido que los niños desarrollanprogresivamente una conciencia metalingühtíca sobre determinados aspectos del sistema lingüístico, nada se sabe de su conciencia (“awareness”) de las funciones del dhcurso. Las propiedades del nivel de discurso (por ejemplo, el empleo de pronombres o sustantivos para marcar la estructura global del discurso) con frecuencia violan propiedades locales del nivel de frase (por ejemplo, precedencia, ambigüedad, etc.). Se presenta una metodología nueva para estudiar el conocimiento metalingüístico que tienen niños y adultos de las propiedades cohesivas y de nivel de discurso de la lengua hablada. Se ha utilizado un dise˜no experimental de dos partes: Una tarea de tiempo de reacción en la que los sujetos tenían que detectar una serie de correcciones (“repairs”) -que sonaban de manera natural- de tipo léxico, referencial y de discurso en unas narraciones, seguida de una entrevhta estructurada de tipo metalingüístico sobre estas correcciones. La parte de detección estableció que los tres tipos de correcciones fueron diferenciadas y se detectaron fácilmente en todas las edades. La parte metalingüística indicó que, si bien tanto los ni˜nos como los adultos pueden proporcionar explicaciones muy adecuadas de correcciones léxicas y referenciales, todos los grupos de edad ofrecieron un rendimiento bajo en relación a la conciencia de las funciones del nivel de discurso de los mismos marcadores lingüísticos. Se exploran varias hipótesis para determinar por qué las funciones de nivel de discurso de estos marcadores no están abiertas a la reflexión metalingüística. Se argumenta que, durante el desarrollo, los dos procesos de codificar el contenido proposicional y codificar la estructura del discur- so compiten entre sí por recursos de procesamiento. En cuanto las dechiones “on line”(en tiempo real) sobre la estructura del discurso se llegan a automatizar, no se almacenan en la memoria a largo plazo y no están disponibles para la reflexión metalingüística. En cambio, la información sobre las características de los marcadores lingüísticos que codifican el contenido proposicional se almacena en la memoria a largo plazo y está disponible para la conciencia metalingüística. La discusión se plantea dentro de una teoría de redescripción representacional que aboga por múltiples recodificaciones del conocimiento en la memoria a largo plazo, recodificaciones que permiten alcanzar niveles más altos de conciencia metalingüística.

La conciencia metalingüística ("metalinguistic awareness") puede incluirse en el desarrollo metacognitivo en general. Aunque se ha establecido que los niños desarrollan progresivamente una conciencia metalingüística sobre determinados aspectos del sistema lingüístico, nada se sabe de su conciencia ("awareness") de las funciones del discurso. Las propiedades del nivel de discurso (por ejemplo, el empleo de pronombres o sustantivos para marcar la estructura global del discurso) con frecuencia violan propiedades locales del nivel de frase (por ejemplo, precedencia, ambigüedad, etc.). Se presenta una metodología nueva para estudiar el conocimiento metalingüístico que tienen niños y adultos de las propiedades cohesivas y de nivel de discurso de la lengua hablada. Se ha utilizado un diseño experimental de dos partes: Una tarea de tiempo de reacción en la que los sujetos tenían que detectar una serie de correcciones ("repairs") - que sonaban de manera natural - de tipo léxico, referencial y de discurso en unas narraciones, seguida de una entrevista estructurada de tipo metalingüístico sobre estas correcciones. La parte de detección estableció que los tres tipos de correcciones fueron diferenciadas y se detectaron fácilmente en todas las edades. La parte metalingüística indicó que, si bien tanto los niños como los adultos pueden proporcionar explicaciones muy adecuadas de correcciones léxicas y referenciales, todos los grupos de edad ofrecieron un rendimiento bajo en relación a la conciencia de las funciones del nivel de discurso de los mismos marcadores lingüísticos. Se exploran varias hipótesis para determinar por qué las funciones de nivel de discurso de estos marcadores no están abiertas a la reflexión metalingüística. Se argumenta que, durante el desarrollo, los dos procesos de codificar el contenido proposicional y codificar la estructura del discurso compiten entre sí por recursos de procesamiento. En cuanto las decisiones "on line"(en tiempo real) sobre la estructura del discurso se llegan a automatizar, no se almacenan en la memoria a largo plazo y no están disponibles para la reflexión metalingüística. En cambio, la información sobre las características de los marcadores lingüísticos que codifican el contenido proposicional se almacena en la memoria a largo plazo y está disponible para la conciencia metalingüística. La discusión se plantea dentro de una teoría de redescripción representacional que aboga por múltiples recodificaciones del conocimiento en la memoria a largo plazo, recodificaciones que permiten alcanzar niveles más altos de conciencia metalingüística. Metalinguistic awareness can be subsumed under metacognitive development in general. Whilst it has been established that children progressively develop metalinguistic awareness about certain aspects of the linguistic system, nothing is known about their awareness of discourse functions. Discourse-level properties (e.g. use of pronouns or nouns to mark the overall discourse structure) often violate local sentential-level properties (e.g. antecedence, ambiguity, etc.). A new methodology forstudying children's and adults' metalinguistic knowledge of the cohesive, discourse-level properties of spoken language is presented. A two-part experimental desing was used: a reaction time task in which subjets had to detect a series of naturally-sounding lexical, referential and discourse repairs in narratives, followed by a structured metalinguistic interview about the repairs. The detection part established that the three types of repair were differentiated and were easily detected at all ages. The metalinguistic part indicated that while both children and adults can furnish very adequate explanations of lexical and referential repairs, all age groups performed poorly with respect to awareness of the discourse-level functions of the same linguistic markers. A number of hypotheses are explored as to why the discourse-level functions of these markers are not open to metalinguistic reflection. It is argued that during development the two processes of encoding propositional content and encoding discourse structure compete for computational resources. Once on-line decisions about discourse structure become automatized, they are not stored in long-term memory and are not available to metalinguistic reflection. By contrast, information about features of linguistic markers that encode propositional content is stored in long-term memory and is available to metalinguistic awareness. The discussion is couched within a theory of representational redescription which argues for multiple re-encodings of knowledge in long-term memory, allowing for increasing levels of metalinguistic awareness.

In this paper, it will be argued that each time a procedure in a representational system is functioning adequately and automatically, the child steps up to a metaprocedural level and considers the procedure as a unit in its own right. Data will be drawn from microdevelopment in children's creation of external memory devices (i.e., changes in representation of a spatial task during a one hour's session) as well as from macrodevelopment in language acquisition (i.e., changes occurring over age in a study of nominal determiners, pronouns and gender markers). These two aspects of development of representational systems are examined with respect to the spontaneous passage from concrete reference to abstract systems, from idiosyncratic to conventional notations, from redundant to economic marking, from unifunctional to plurifunctional meaningful units. These micro‐ and manodevelopmental changes take place in a spontaneous fashion despite the fact that the child's earlier system is adequate for successfully conveying the information required. A discussion will be made of the way in which children tend to indicate externally, by unifunctional markers, information which was implicit in their earlier use of an adult‐like system. They appear to be striving for the delicate balance between encoding and decoding efforts, ultimately leading to a felicitous representational system. Metaprocedural behavior is hypothesized to act as a control mechanism in the striving for this delicate balance of information content and information processing effort. It also appears to act as a control mechanism for the interprocedural organizotion of what was previously a plethora of juxtaposed, unconnected procedures yielding superficially analogous behavior. The stepping‐up to a metaprocedural level seems to occur each time the child has a handle on his currently functioning, goal‐oriented system. This enables the child to treat the system, or procedures which are part thereof, as units functioning in their own right. Thus there appears to be a deep‐rooted psychological tendency for a representational tool which functions well procedurally to become subsequently a problem‐space per se.

Aunque las investigaciones de Ginebra han proporcionado un análisis detallado de las estructuras cognitivas, nuestro conocimiento de los procesos cognitivos sigue siendo fragmentario. El interés se centra ahora no sólo en el macro-desarrollo sino también en los cambios que tienen lugar en las secuencias de acción espontánea de los niños en microformación. Están en marcha una serie de experimentos diseñados con el fin de estudiar la conducta dirigida hacia una meta. Este artículo describe las secuencias de acción de 67 sujetos entre 4;6 y 9;5 años en una tarea de equilibrio de bloques. Noes un estudio de la comprensión de una noción específica por parte de los niños, sino un intento por abrir el camino a la comprensión de los procesos más generales de la conducta cognitiva. El análisis se centra en la interacción entre las secuencias de acción de el niño y sus teorías implícitas, que el observador infiere a partir de las secuencias más que de sus comentarios verbales. Se pone énfasis en el papel de los contraejemplos y en los desplazamientos de la atención desde el fin a los medios. La construcción y la sobregeneralización de «teorías-en-acción» parecen ser procesos generales y dinámicos que no están vinculados a ningún estadio. Los resultados sugieren también ciertas analogías, más funcionales que estructurales, entre la adquisición del conocimiento físico y la adquisición del lenguaje.

Many species can respond to the behaviorof their conspecifics. Human children, and perhaps some nonhuman primates, also have the capacity to respond to the mental statesof their conspecifics, i.e., they have a “theory of mind.” On the basis of previous research on the theory-of-mind impairment in people with autism, together with animal models of intentionality, Brothers and Ring (1992) postulated a broad cognitive module whose function is to build representations of other individuals. We evaluate the details of this hypothesis through a series of experiments on language, face processing, and theory of mind carried out with subjects with Williams syndrome, a rare genetic neurodevelopmental disorder resulting in an uneven lin-guisticocognitive profile. The results are discussed in terms of how the comparison of different phenotypes (e.g., Williams syndrome, Down syndrome, autism, and hydrocephaly with associated myelomeningocele) can contribute both to understanding the neuropsychology of social cognition and to current thinking about the purported modularity of the brain.

The article discusses the impact of bilingualism on children's cognitive development and learning process. According to the rhythmic structures of their sound patterns, languages can be categorized as stress-based, syllable-based or mora-based. Findings from a study by Nuria Sebastian-Galles revealed that infants brought up bilingually were delayed in perceptual narrowing and the ability to detect mispronunciations. Similar study indicates that bilingual babies pay less attention to detail and process speech sound more globally.

The article explores some scientific research that analyzed the relationship between screen exposure and child development. Studies cite several factors that make pre-school television viewing positive, including repetition, predictability, and ensuring that infants move their eyes during screen exposure. Research has also demonstrated that from at least six months old, infants can successfully encode what they observe on screen, store it in memory and later produce imitative actions. Studies also suggest the need to control and limit screen exposure.

The article discusses infants' sensitivity to some numerical aspects of visual and auditory displays, including numerical processing even in the first post-natal weeks. It mentions that experiments show that babies as young as five months old have addition and subtraction abilities of tracking objects as they move about in space, provided that the number of objects is small. It concludes that the human capacity for mathematics evolved very ancient in evolution.

The article revisits the relevance of Swiss developmental psychologist Jean Piaget's theory of infant brain development. It presents an overview of the main components of Piaget's theory, which include three biologically-inspired mechanisms invoked in progressively internalising knowledge. It discusses the Constructivist and Neuroconstructivist perspectives in relation to the dynamics of infant development. The article also explores the implications of a Neuroconstructivist approach for atypical development.

Recent technological advances allow us to measure how the infant brain functions in ways that were not possible just a decade ago. Although methodological advances are exciting, we must also consider how theories guide research: what we look for and how we explain what we find. Indeed, the ways in which research findings are interpreted affects the design of policies, educational practices, and interventions. Thus, the theoretical approaches adopted by scientists have a real impact on the lives of children with neurodevelopmental disorders (NDDs) and their families, as well as on the wider community. Here, we introduce and compare two theoretical approaches that are used to understand NDDs: the neuropsychological accountand neuroconstructivism. We show how the former, adult account, is inadequate for explaining NDDsand illustrate this using the examples of Williams syndrome and specific language impairment. Neuroconstructivism, by contrast, focuses on the developing organism and is helping to change the way in which NDDsare investigated. Whereas neuropsychological static approaches assume that one or more ‘modules’ (e.g., visuospatial ability in Williams syndrome) are impaired while the rest of the system is spared (e.g., language in Williams syndrome), neuroconstructivism proposes that basic‐level deficits have subtle cascading effects on numerous domains over development. Neuroconstructivism leads researchers to embrace complexity by establishing large research consortia to integrate findings at multiple levels (e.g., genetic, neural, cognitive, environmental) across developmental time. WIREs Cogn Sci2017, 8:e1398. doi: 10.1002/wcs.1398 For further resources related to this article, please visit the WIREs website.