Sleep problems in children with cerebral palsy and their relationship with maternal sleep and depression.

AIM: To compare sleep problems in children with cerebral palsy to typically developing children. To study the relationship between sleep problems in children with cerebral palsy and maternal sleep quality and depression. METHODS: Fifty-seven children with cerebral palsy aged 4-12 years were identified from a UK disability database. Maternal sleep disturbance and mood were assessed using the Pittsburgh Sleep Quality Index and the Major Depression Inventory. Child sleep problems, assessed with the Children's Sleep Habits Questionnaire, but not maternal variables, were compared to 102 typically developing children. RESULTS: Forty children (70%) were recruited with a mean age of 7.8 (SD 2.4). Sleep anxiety, night wakings, parasomnias and sleep-disordered breathing sub-scales indicated significantly more difficulties than in typically developing children. 40% of mothers of children with cerebral palsy had poor sleep quality of whom 44% had depressed mood. Child and maternal sleep disturbance were significantly correlated. Maternal sleep quality predicted 50% of the variance in maternal depression. CONCLUSIONS: Children with cerebral palsy have more sleep problems than typically developing peers. Their mothers also have disturbed sleep that correlates with maternal depression. Childhood sleep problems can be treated and should be identified in routine clinical practice.

Young children with autism spectrum disorder do not preferentially attend to biological motion.

Preferential attention to biological motion can be seen in typically developing infants in the first few days of life and is thought to be an important precursor in the development of social communication. We examined whether children with autism spectrum disorder (ASD) aged 3-7 years preferentially attend to point-light displays depicting biological motion. We found that children with ASD did not preferentially attend to biological motion over phase-scrambled motion, but did preferentially attend to a point-light display of a spinning top rather than a human walker. In contrast a neurotypical matched control group preferentially attended to the human, biological motion in both conditions. The results suggest a core deficit in attending to biological motion in ASD.

Variability and standardized test profiles in typically developing children and children with Williams Syndrome.

Williams Syndrome (WS) is a developmental disorder, which due to its specific cognitive profile, has been of interest to multidisciplinary research in order to study the pathways between cognition, brain, and genes. Previous studies investigating individual performance on cognitive tasks have reported large variability within the WS cognitive profile, which has encouraged the investigation of WS subgroups. The current study compared the variability in performance scores on five verbal and non-verbal standardized tests in 33 children with WS and in 33 typically developing (TD) children of a similar chronological age (CA). In contrast to previous studies, the current study did not find significant differences in variability in performance on British Picture Vocabulary scale, Test Reception of Grammar and Digit span Forward between WS and TD groups when CA was controlled for. However, there was significantly less variability in younger WS participants for performance scores on Pattern Construction compared to the TD group. In light of these results, methodological issues and the importance of taking CA into account in analyses will be discussed.

Developing spatial frequency biases for face recognition in autism and Williams syndrome.

The current study investigated whether contrasting face recognition abilities in autism and Williams syndrome could be explained by different spatial frequency biases over developmental time. Typically-developing children and groups with Williams syndrome and autism were asked to recognise faces in which low, middle and high spatial frequency bands were masked. All three groups demonstrated a gradual specialisation toward the mid-band. However, while the use of high spatial frequencies decreased in control and autism groups over development, the Williams syndrome group did not display a bias toward this band at any point. These data demonstrate that typical outcomes can be achieved through atypical developmental processes, and confirm the importance of cross-syndrome studies in the investigation of developmental disorders.

Characterisation of sleep problems in children with Williams syndrome.

Sleep is critical to optimal daytime functioning, learning and general health. In children with established developmental disorders sleep difficulties may compound existing learning difficulties. The purpose of the present study was to evaluate the prevalence and syndrome specificity of sleep problems in Williams syndrome (WS), a neurodevelopmental disorder affecting around 1 in 20,000 live births. Parents of 64 children with WS, aged 6-12 years, and 92 age matched healthy controls were surveyed about their child's sleep habits. The Child Sleep Habits Questionnaire, general health and background information were collected from the parents. Ninety seven percent of parents reported that their children had sleep problems and reported a high prevalence of sleep difficulties: greater bedtime resistance, sleep anxiety, night waking and daytime sleepiness. This is the first study to our knowledge to survey sleep problems in a large cohort of school age children with WS. Sleep problems in children with learning difficulties are often amendable to treatment if diagnosed early. Furthermore the negative impact of sleep disturbances on daytime behaviour and learning should be measured before diagnoses of behaviourally defined disorders are considered.

Item and error analysis on Raven's Coloured Progressive Matrices in Williams Syndrome.

Raven's Coloured Progressive Matrices (RCPM) is a standardised test that is commonly used to obtain a non-verbal reasoning score for children. As the RCPM involves the matching of a target to a pattern it is also considered to be a visuo-spatial perception task. RCPM is therefore frequently used in studies in Williams Syndrome (WS), in order to match WS participants to a control group or as a single measure to predict performance on a test-condition in developmental trajectory analyses. However, little is known about the performance of participants with WS on the RCPM. The current study compared the type of errors and the difficulty of each item for 53 participants with WS to 53 typically developing children who were individually matched on the total raw score for RCPM. Results showed that the participants with WS made the same proportion of error types and that the proportion of error types changed similarly to those of typically developing controls over development. Furthermore, the differential item difficulty between the two groups was highly similar. It is therefore argued that, although participants with WS are delayed on RCPM, their performance is not atypical which suggests that RCPM performance is supported by typical mechanisms. The RCPM is therefore a useful tool to match WS to control groups or to construct developmental trajectories.

Development of motion processing in children with autism.

Recent findings suggest that children with autism may be impaired in the perception of biological motion from moving point-light displays. Some children with autism also have abnormally high motion coherence thresholds. In the current study we tested a group of children with autism and a group of typically developing children aged 5 to 12 years of age on several motion perception tasks, in order to establish the specificity of the biological motion deficit in relation to other visual discrimination skills. The first task required the recognition of biological from scrambled motion. Three quasi-psychophysical tasks then established individual thresholds for the detection of biological motion in dynamic noise, of motion coherence and of form-from-motion. Lastly, individual thresholds for a task of static perception--contour integration (Gabor displays)--were also obtained. Compared to controls, children with autism were particularly impaired in processing biological motion in relation to any developmental measure (chronological or mental age). In contrast, there was some developmental overlap in ability to process other types of visual motion between typically developing children and the children with autism, and evidence of developmental change in both groups. Finally, Gabor display thresholds appeared to develop typically in children with autism.

Development of metaphor and metonymy comprehension: receptive vocabulary and conceptual knowledge.

Figurative language, such as metaphor and metonymy are common in our daily communication. This is one of the first studies to investigate metaphor and metonymy comprehension using a developmental approach. Forty-five typically developing individuals participated in a metaphor-metonymy verbal comprehension task incorporating 20 short picture-stories. Cross-sectional trajectory analyses linking task performance to either chronological age or receptive vocabulary (mental age, MA) were used to compare the development of metaphor and metonymy. Results showed that development of metaphor and metonymy comprehension is strongly linked with chronological and MA, but metaphor comprehension develops at a slower rate compared to metonymy. It was also found that participants, across all ages, consistently showed around 21% better performance on metonymy. The relationship between metaphor and metonymy comprehension is discussed in terms of linguistic and cognitive models of figurative language comprehension arguing that metonymy is cognitively more basic than metaphor.

The atypical development of metaphor and metonymy comprehension in children with autism.

One of the most noticeable problems in autism involves the social use of language such as metaphor and metonymy, both of which are very common in daily language use. The present study is the first to investigate the development of metaphor and metonymy comprehension in autism. Eleven children with autism were compared to 17 typically developing children in a metaphor-metonymy comprehension task. Cross-sectional trajectory analyses were used to compare the development of metaphor and metonymy comprehension using a child-friendly story picture task. Trajectories were constructed linking task performance either to chronological age or to measures of mental age. Children with autism showed an impaired metaphor comprehension in relation to both chronological and mental age, whereas performance on metonymy was delayed and in line with their receptive vocabulary. Our results suggest that understanding of metaphors and metonyms are severely affected at all ages examined in the current study.

Comprehension of metaphor and metonymy in children with Williams syndrome.

BACKGROUND: Figurative language, such as metaphor and metonymy, is very common in daily language use. Its underlying cognitive processes are sometimes viewed as lying at the interface of language and thought. Williams syndrome, which is a rare genetic developmental disorder, provides an opportunity to study this interface because individuals with this disorder have relative strengths in vocabulary and syntax against a background of low general cognitive ability. Few studies have investigated metaphor comprehension in Williams syndrome and none has investigated metonymy. AIMS: This is the first study to investigate metaphor and metonymy comprehension in Williams syndrome and to compare their performance with a group of typically developing children. METHODS & PROCEDURES: Ten children with Williams syndrome were compared with eleven typically developing children in a novel metaphor-metonymy comprehension task. Cross-sectional trajectory analyses were used to compare the development of metaphor and metonymy using a child-friendly story picture task. Trajectories were constructed linking task performance either to chronological age or to measures of mental age (receptive vocabulary, visuospatial construction). OUTCOMES & RESULTS: The performance of children with Williams syndrome was significantly poorer than the typically developing group. The comprehension of metonyms was in line with receptive vocabulary, but comprehension of metaphors fell below this level. CONCLUSIONS & IMPLICATIONS: Metonyms may be part of vocabulary and treated as synonyms in Williams syndrome, while metaphor engages additional cognitive mechanisms outside language that develop atypically in this disorder. Despite earlier reports that emphasize good language skills, the Williams syndrome language system shows anomalies compared with typical development.

Using developmental trajectories to understand developmental disorders.

PURPOSE: In this article, the authors present a tutorial on the use of developmental trajectories for studying language and cognitive impairments in developmental disorders and compare this method with the use of matching. METHOD: The authors assess the strengths, limitations, and practical implications of each method. The contrast between the methodologies is highlighted using the example of developmental delay and the criteria used to distinguish delay from atypical development. RESULTS: The authors argue for the utility of the trajectory approach, using illustrations from studies investigating language and cognitive impairments in individuals with Williams syndrome, Down syndrome, and autism spectrum disorder. CONCLUSION: Two conclusions were reached: (a) An understanding of the underlying mechanism will be furthered by the richer descriptive vocabulary provided by the trajectories approach (e.g., in distinguishing different types of delay) and (b) an optimal design for studying developmental disorders is to combine initial cross-sectional designs with longitudinal follow-up.

A cross-syndrome study of the development of holistic face recognition in children with autism, Down syndrome, and Williams syndrome.

We report a cross-syndrome comparison of the development of holistic processing in face recognition in school-aged children with developmental disorders: autism, Down syndrome, and Williams syndrome. The autism group was split into two groups: one with high-functioning children and one with low-functioning children. The latter group has rarely been studied in this context. The four disorder groups were compared with typically developing children. Cross-sectional trajectory analyses were used to compare development in a modified version of Tanaka and Farah's part-whole task. Trajectories were constructed linking part-whole performance either to chronological age or to several measures of mental age (receptive vocabulary, visuospatial construction, and the Benton Facial Recognition Test). In addition to variable delays in onset and rate of development, we found an atypical profile in all disorder groups. These profiles were atypical in different ways, indicating multiple pathways to, and variable outcomes in, the development of face recognition. We discuss the implications for theories of face recognition in both atypical and typical development, including the idea that part-whole and rotation manipulations may tap different aspects of holistic and/or configural processing.

Exploring the Williams syndrome face-processing debate: the importance of building developmental trajectories.

BACKGROUND: Face processing in Williams syndrome (WS) has been a topic of heated debate over the past decade. Initial claims about a normally developing ('intact') face-processing module were challenged by data suggesting that individuals with WS used a different balance of cognitive processes from controls, even when their behavioural scores fell within the normal range. Measurement of evoked brain potentials also point to atypical processes. However, two recent studies have claimed that people with WS process faces exactly like normal controls. METHOD: In this paper, we examine the details of this continuing debate on the basis of three new face-processing experiments. In particular, for two of our experiments we built task-specific full developmental trajectories from childhood to adolescence/adulthood and plotted the WS data on these trajectories. RESULTS: The first experiment used photos of real faces. While it revealed broadly equivalent accuracy across groups, the WS participants were worse at configural processing when faces were upright and less sensitive than controls to face inversion. In Experiment 2, measuring face processing in a storybook context, the face inversion effect emerged clearly in controls but only weakly in the WS developmental trajectory. Unlike the controls, the Benton Face Recognition Test and the Pattern Construction results were not correlated in WS, highlighting the different developmental patterns in the two groups. Again in contrast to the controls, Experiment 3 with schematic faces and non-face stimuli revealed a configural-processing deficit in WS both with respect to their chronological age (CA) and to their level of performance on the Benton. CONCLUSION: These findings point to both delay and deviance in WS face processing and illustrate how vital it is to build developmental trajectories for each specific task.