The development of responses to people and a toy in infants with down syndrome

The behavior of eight infants with Down syndrome was observed biweekly from 8 to 24 weeks and monthly up to 48 weeks. At each visit the infants were presented with their mother, a female stranger, and a rattle puppet that were alternately active and passive. Each condition lasted 60 s. The results showed that by 4 months of age the infants began to differentiate, in the proportion of time they looked, smiled, and vocalized, between people and the toy. They did not discriminate, however, between mother and female stranger and between the active and passive adults until the second half of the first year. In particular, whereas normal infants usually show distress toward passive or “still-face” adults, the infants in this study continued to vocalize, at times even with smiling faces. The implications of these atypical aspects of the social development of infants with Down syndrome for their subsequent nonverbal communicative development are discussed.     

The effect of manual movements on stuttering in individuals with down syndrome

PurposeStuttering may disrupt the speech of individuals with Down syndrome (DS), but standard stuttering therapies may be less adapted to these clients’ needs. This study examined if their strength in gesture use can lead to the development of a new stuttering therapy.MethodEighteen individuals with DS who stutter participated in an experimental task. During this task, they produced sentences in three different conditions: once without the ability to use gestures, once while moving the mouth of a hand puppet synchronous with their speech, and once while making beat gestures along their speech. Stuttering frequency was measured and compared between conditions while controlling for the effect of articulation rate.ResultsThe experimental hand puppet and beat condition did not affect the stuttering frequency, but the covariate articulation rate did. An exploratory posthoc analysis showed that the articulation rate decreased during the experimental hand puppet and beat condition. Manual movements in the present task might only induce fluency through articulation rate reduction. However, analyses at individual level show significant interindividual variability.ConclusionIndividual analyses show that effect on stuttering frequency cannot be attributed entirely to articulation rate reduction and that beat gestures might still play a role. However, at this point, there is not enough direct evidence to implement beat gestures in current stuttering therapy.     

Exploratory behavior and developmental skill acquisition in infants with Down syndrome

Infants learn about objects by exploring them. Typically developing infants actively explore objects through visual, manual, and oral modalities. Attenuated exploratory behavior has been observed in various neurodevelopmental disorders, including Down syndrome (DS), presumably limiting learning options. However, a direct link between exploration and overall developmental functioning has not been characterized. This study used a Latent Profile Analysis framework to examine within-syndrome variability in exploratory behavior in infants with DS and the developmental correlates of different exploratory behavior profiles. Participants were 45 infants with DS (CA = 9.58 months; SD = 3.62) who completed an object exploration activity and the Bayley Scales of Infant Development-III (BSID-III; Bayley, 2006). Exploration behavior was coded for the percentage of time engaged in visual, manual, and oral exploration. Results indicated that a 2-profile solution provided the best model fit for exploratory behavior, yielding profiles that represented either an Active (57.78% of the sample) or a Passive Exploratory (42.22% of the sample) profile. The Active Exploratory profile was associated with significantly higher age equivalent scores on the BSID-III Cognitive, Communication, and Motor domains than the Passive Exploratory profile. Other factors, such as sex and biomedical risk factors, were not associated with exploratory profiles. These findings offer a more nuanced understanding of early within-syndrome heterogeneity in DS, and demonstrate that impoverished early exploratory behavior may serve as an important indicator of increased risk for more pronounced developmental delays in DS.     

Physical activity in infants with Down syndrome receiving a treadmill intervention

Despite the recognized relevance of physical activity in the development and health of children, assessment of physical activity levels (PA-level) in infancy is limited, especially in infants with Down syndrome (DS). Increasing PA-level using a treadmill training (TMT) intervention may benefit infants with motor delays. The purpose of this study was to investigate whether a higher intensity, individualized TMT protocol (HI) would elicit immediate and short-term higher PA-level in infants with DS than a lower intensity, generalized training protocol (LG).Thirty infants with DS were randomly assigned to the LG or the HI group. Training was terminated when the infants could walk three steps independently. Activity monitors were placed on infants’ trunks and legs for a 24-h period every other month during the intervention phase, and at set intervals 1-year post-independent walking onset. Data were analyzed to separate sedentary-to-light activity (Lowact) and moderate-to-vigorous activity (Highact).Overall our results demonstrate that infants receiving the HI TMT had higher levels of Highact than infants in the LG group, factoring out the activity produced by the intervention itself. Infants in the LG group spent more time in Lowact than the HI group. In addition, these results seemed to be retained during the post-intervention follow-up. Despite these exciting results, more work is needed to understand the relationship of the intensity of TMT on PA-level in infants with DS, and whether PA-level and TMT are related to motor milestone achievement and/or health benefits.     

Parents attributions of blame for the birth of a child with down syndrome: A pilot study

Abstract

Attributing blame to others for negative events is consistently associated with poor adjustment. We report here a study assessing whether failure to detect a problem on screening, in this case Down syndrome not detected during prenatal screening, is associated with blame and poor adjustment in parents. Twenty eight mothers and 23 fathers of children with Down syndrome were interviewed. Although no parent blamed themselves or their partner, eight fathers and five mothers blamed health professionals or the health care system in general for not preventing the birth of their children with Down syndrome prenatally. None of the parents who declined testing were blaming. Six of the 11 parents who received a negative test and seven of the 34 not offered a test blamed others. Both mothers and fathers who blamed others reported significantly higher parenting stress. Mothers, but not fathers, who blamed others were significantly more angry and depressed than those who did not.     

Effects on fathers of children with down syndrome

This study investigated research evidence for eight assertions found in the literature about effects on fathers of children with disabilities. Eighty-seven fathers of children with Down syndrome completed questionnaire instruments designed to measure demographic variables, adaptation, stress, personality, social support and marital functioning. The results provided little support for most of the assertions. It is concluded that the existing literature provides a somewhat erroneous perspective of the experiences of such fathers. These findings reinforce the need for further research specifically with fathers of children with mental retardation.     

Maternal sensitivity and overt aggression in young children with Down syndrome

Children with genetic syndromes offer a unique opportunity to combine genetic and environmental approaches to the study of aggression. Children with genetic syndromes associated with developmental delay are at increased risk for behavior problems, but little is known about risk and resilience factors. In this study, we examined maternal sensitivity of mothers of children with Down syndrome using home observations when their children were 2, 3, and 5 years old, and relations with maternal reports and observations of overt aggression at school at age 5. Maternal sensitivity at ages 2 and 3 years did not significantly predict child aggression at age 5, but low maternal sensitivity at age 5 was significantly related to overt aggression at both home and school. By replicating and extending earlier work, this study informs developmental theory and identifies an important maternal variable related to aggression in children with Down syndrome.     

First symbols in a girl with Down syndrome: A longitudinal study from 12 to 18 months

Symbolic uses of objects originate in communicative and triadic contexts (adult–child-object). In this longitudinal study we explore the emergence and development of the first symbolic uses in triadic interaction contexts in a girl with Down syndrome between 12 and 18-months of age. We conducted five sessions of video recording, at 12, 13½, 15, 16½, and 18 months chronological age. At each session we videotaped the girl and her mother interacting with different objects. Data were coded in semiotic categories used in previous studies (Rodríguez & Moro, 1999) and a microgenetic analysis was conducted for each session. The first symbolic uses by the girl appeared at 13½ months. Symbols were of different types and levels of complexity, and the adult had an important role in facilitating the production of these symbols.     

Auditory information is beneficial for adults with Down syndrome in a continuous bimanual task

Much recent research using discrete unimanual tasks has indicated that individuals with Down syndrome (DS) have more difficulty performing verbal-motor tasks as compared to visual-motor tasks (see Perceptual-Motor Behavior in Down Syndrome, Human Kinetics, Champaign, IL, 2000, p. 305 for a review). In continuous tasks, however, individuals with DS perform better when movement is guided by auditory information compared to visual information (Downs Syndr.: Res. Prac. 4 (1996) 25; J. Sport Exercise Psy. 22 (2000) S90). The aim of the present study was to investigate if there are any differences for adults with DS between visual, auditory and verbal guidance in a continuous bimanual task. Ten adults with DS, 10 adults without DS and 10 typically developing children drew lines bimanually towards the body (down) and away from the body (up) following three different guidance conditions: visual (flashing line), auditory (high tone, low tone), and verbal (“up”, “down”). All participants produced mostly in-phase movements and were close to the 1000 ms target time for all guidance conditions. The adults with DS, however, displayed greater variability in their movement time, movement amplitude and bimanual coordination than adults without DS. For all groups, the left hand was slower and more variable in producing the lateral movements than the right hand. The results regarding guidance information suggest that auditory information is beneficial for repetitive bimanual tasks for adults with DS. Possible mechanisms that cause these results will be discussed.     

Changes in lower limb co-contraction and stiffness by toddlers with Down syndrome and toddlers with typical development during the acquisition of independent gait

During gait acquisition, children learn to use their changing resources to meet the requirements of the task. Compared to typically developing toddlers (TD), toddlers with Down syndrome (DS) have functionally different musculoskeletal characteristics, such as hypotonia, and joint and ligament laxity, that could produce a reduced passive stiffness. The interplay between this inherently lower passive stiffness and the demands of walking may result in different strategies during gait acquisition. This study compared normalized global stiffness and lower limb's co-contraction indices (CCI) used by toddlers with TD (n=12) and with DS (n=12), during the early stages of gait acquisition. Stiffness and CCI were normalized by gravitational torque (mLg) in both phases of gait (stance, swing). Five longitudinal evaluations were conducted from the onset of locomotion until three months post-acquisition. All children were video taped and had electromyographic (EMG) recordings from muscle pairs of one leg, which were used to calculate CCI of hip, knee, ankle, and total leg CCI. Body and lower limb stiffness were calculated according to a hybrid pendulum resonance equation. Results from ANOVAs revealed no group differences on stiffness or on CCI's during stance but children with DS showed greater CCI during swing. Despite the structural musculoskeletal differences between toddlers with TD and with DS, the similarities observed in their processes of gait development suggest functional equivalences.     

Facial emotion recognition in Williams syndrome and Down syndrome: A matching and developmental study

In this study both the matching and developmental trajectories approaches were used to clarify questions that remain open in the literature on facial emotion recognition in Williams syndrome (WS) and Down syndrome (DS). The matching approach showed that individuals with WS or DS exhibit neither proficiency for the expression of happiness nor specific impairments for negative emotions. Instead, they present the same pattern of emotion recognition as typically developing (TD) individuals. Thus, the better performance on the recognition of positive compared to negative emotions usually reported in WS and DS is not specific of these populations but seems to represent a typical pattern. Prior studies based on the matching approach suggested that the development of facial emotion recognition is delayed in WS and atypical in DS. Nevertheless, and even though performance levels were lower in DS than in WS, the developmental trajectories approach used in this study evidenced that not only individuals with DS but also those with WS present atypical development in facial emotion recognition. Unlike in the TD participants, where developmental changes were observed along with age, in the WS and DS groups, the development of facial emotion recognition was static. Both individuals with WS and those with DS reached an early maximum developmental level due to cognitive constraints.     

Spoken and gestural production in a naming task by young children with Down syndrome

Lexical production in children with Down syndrome (DS) was investigated by examining spoken naming accuracy and the use of spontaneous gestures in a picture naming task. Fifteen children with DS (range 3.8-8.3 years) were compared to typically developing children (TD), matched for chronological age and developmental age (range 2.6-4.3 years). Relative to TD children, children with DS were less accurate in speech (producing a greater number of unintelligible answers), yet they produced more gestures overall and of these a significantly higher percentage of iconic gestures. Furthermore, the iconic gestures produced by children with DS accompanied by incorrect or no speech often expressed a concept similar to that of the target word, suggesting deeper conceptual knowledge relative to that expressed only in speech.     

Receptive vocabulary and semantic knowledge in children with SLI and children with Down syndrome

Receptive vocabulary and associated semantic knowledge were compared within and between groups of children with specific language impairment (SLI), children with Down syndrome (DS), and typically developing children. To overcome the potential confounding effects of speech or language difficulties on verbal tests of semantic knowledge, a novel task was devised based on picture-based semantic association tests used to assess adult patients with semantic dementia. Receptive vocabulary, measured by word-picture matching, of children with SLI was weak relative to chronological age and to nonverbal mental age but their semantic knowledge, probed across the same lexical items, did not differ significantly from that of vocabulary-matched typically developing children. By contrast, although receptive vocabulary of children with DS was a relative strength compared to nonverbal cognitive abilities (p < .0001), DS was associated with a significant deficit in semantic knowledge (p < .0001) indicative of dissociation between word-picture matching vocabulary and depth of semantic knowledge. Overall, these data challenge the integrity of semantic-conceptual development in DS and imply that contemporary theories of semantic cognition should also seek to incorporate evidence from atypical conceptual development.     

Fathers' views of the effects on their families of children with Down syndrome

This study examined fathers' views about the effects of children with Down syndrome on themselves and their families. Taped interviews were obtained from 90 fathers of children aged from 7 to 14 years. Qualitative analysis of the interview data revealed 28 categories of comments made by fathers. The most frequent comment, made by 46% of fathers, was about the cheerful personality of their child with Down syndrome. About 42% of fathers talked about the initial trauma they experienced following the diagnosis; 43% of them bemoaned the restrictions imposed on the family, and 30% commented that the child had minimal effects on family life. The greatest concern expressed by fathers was the long-term provision for their children. More fathers commented on the positive effects on their marriage than on negative effects. The results of this study provide a somewhat different view of fathers' experiences to that found in the existing literature.     

Differences in visual orienting between persons with Down or fragile X syndrome

The voluntary and reflexive orienting abilities of persons with Down syndrome and fragile X syndrome, at average MA levels of approximately 4 and 7 years, were compared with an RT task. Reflexive orienting abilities appeared to develop in accordance with MA for the participants with Down syndrome but not for those with fragile X syndrome. However, both groups showed delayed voluntary orienting. The group differences in reflexive orienting at the low MA level reinforce the practice of separating etiologies and highlight the contribution of rudimentary attentional processes in the study of individuals with mental retardation.     

Memory coding in individuals with Down syndrome

Previous research has identified a deficit in phonological short-term memory in individuals with Down syndrome.

The present work aimed to analyze how a group of 30 individuals with Down syndrome performed in a picture span task compared with 30 typically developing children of the same mental age. The task involved four conditions (i.e., dissimilar, phonologically similar, visually similar, and long-name items) chosen to analyze the strategy used by individuals with Down syndrome to code visually presented nameable items.

Individuals with Down syndrome performed less well than typically developing children. Both groups showed the visual similarity effect.

Taken together, our results confirm that individuals with Down syndrome have a verbal working memory deficit, even when nameable items are presented visually. Mental age appears to be an important determinant of memory coding stage in individuals with Down syndrome.     

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.     

Neural correlates of music recognition in Down syndrome

The brain mechanisms that subserve music recognition remain unclear despite increasing interest in this process. Here we report the results of a magnetoencephalography experiment to determine the temporal dynamics and spatial distribution of brain regions activated during listening to a familiar and unfamiliar instrumental melody in control adults and adults with Down syndrome (DS). In the control group, listening to the familiar melody relative to the unfamiliar melody, revealed early and significant activations in the left primary auditory cortex, followed by activity in the limbic and sensory-motor regions and finally, activation in the motor related areas. In the DS group, listening to the familiar melody relative to the unfamiliar melody revealed increased significant activations in only three regions. Activity began in the left primary auditory cortex and the superior temporal gyrus and was followed by enhanced activity in the right precentral gyrus. These data suggest that familiar music is associated with auditory–motor coupling but does not activate brain areas involved in emotional processing in DS. These findings reveal new insights on the neural basis of music perception in DS as well as the temporal course of neural activity in control adults.     

A variable that may affect individual differences in the child-directed speech of Japanese women

Sixty-one single Japanese-speaking women between the ages of 18 and 26 years were recorded as they read aloud picture books to a young child and as they conversed with another Japanese-speaking woman. When their utterances were acoustically compared between the two settings with regard to prosodic features, both the average pitch and pitch excursions exhibited a significant increase when interacting with the child in 17 of the 61 women. In 36 of the remaining 44 subjects, neither of these parameters showed such changes. This individual variability was not related to the subjects' liking for picture books, previous experience with reading or being read them, or with baby-sitting. The only variable that could explain the results was whether the subjects had grown up with one or more siblings or as only children. If they were only children, the prosodic modification was significantly less likely to occur