Early socio-communicative forms and functions in typical Rett syndrome

Rett syndrome (RTT) is a severe neurological disorder characterized by a developmental regression in motor and speech-language domains. There is, however, limited research on socio-communicative development of affected children before the onset of regression. We analyzed audio–video recordings made by parents of six 9- to 12-month old girls later diagnosed with typical RTT, applying the Inventory of Potential Communicative Acts (IPCA) to identify early communicative forms and functions. Each girl used at least one communicative form (e.g., body movement, eye gaze, or vocalizations) to gain attention and answer, but none were observed to make choices or request information. Varying numbers of children were observed to perform other communicative functions according to the IPCA including social convention, rejecting or requesting an object. Non-verbal forms (e.g., reaching, moving closer, eye contact, smiling) were more common than non-linguistic verbal forms (e.g., unspecified vocalizations, pleasure vocalizations, crying). (Pre-)linguistic verbal forms (e.g., canonical or variegated babbling, proto-words) were not used for communicative purposes. These data suggest that atypical developmental patterns in the socio-communicative domain are evident prior to regression in young individuals later diagnosed with RTT.     

Profiling early socio-communicative development in five young girls with the preserved speech variant of Rett syndrome

Rett syndrome (RTT) is a developmental disorder characterized by regression of purposeful hand skills and spoken language, although some affected children retain some ability to speech. We assessed the communicative abilities of five young girls, who were later diagnosed with the preserved speech variant of RTT, during the pre-regression period (aged 12-24 months). Videotapes, obtained by parents during routine family situations and celebrations, were analyzed to identify communicative forms and functions used by these toddlers. Non-verbal communicative forms dominated over verbal-communicative forms for six of the eight identified communication functions. Although the girls used various non-verbal forms to make requests, for example, none of the individuals were observed to make choices or request information. Early peculiarities in the speech-language domain during the first year of life became more prominent and evident during the second year of life as general differences between typical development and atypical development become more obvious in RTT. These findings highlight the importance of assessing socio-communicative forms and functions at early age in children with RTT. The results suggest that speech-language functions did not appear to play a major role in the children's communicative attempts. We conclude that, even among children with the preserved speech variant, socio-communicative deficits are present before regression and persist after this period.     

Three different profiles: Early socio-communicative capacities in typical Rett syndrome,the preserved speech variant and normal development

Background and aims: This is the first study aiming to compare pre-diagnostic socio-communicative development of a female with typical Rett syndrome (RTT), a female with the preserved speech variant of RTT (PSV) and a control toddler.

Methods: We analysed 1275?min of family videos at the participants’ age between 9 and 24 months and used the Inventory of Potential Communicative Acts (IPCA) to delineate their repertoires of communicative forms and functions.

Results: The results revealed different profiles for the three different conditions. The repertoire of communicative gestures and (pre)linguistic vocalizations was most comprehensive in the control toddler, followed by the female with PSV and the female with RTT.

Conclusion: These findings contribute to the growing knowledge about early developmental abnormalities in RTT. In order to define distinctive profiles for typical and atypical RTT and evaluate their specificity, a larger body of evidence is needed.     

Motor abilities of children diagnosed with fragile X syndrome with and without autism

Background   Previous studies suggested that children diagnosed with fragile X syndrome (FXS) often meet criteria for autism or PDD. This study describes the fine motor abilities of children diagnosed with FXS with and without autism spectrum disorder, and compares the motor scores of those groups controlling for cognitive level.
Method   Forty-eight children, ages 12–76 months (SD = 16) diagnosed with FXS were assessed with the Mullen Scales of Early Learning, and the Autism Diagnostic Observation Schedule. Their parents were interviewed with the Autism Diagnostic Interview-Revised. We used a one-way analysis of variance to determine if the fine motor scale of the Mullen would show group differences based on autism classifications for the sample. In addition, we used Pearson correlation coefficient to examine the relationship between the cognitive level, the autism severity and the motor abilities. Lastly, we conducted a one-way analysis of covariance to determine the difference between the motor abilities of the Autism Spectrum Disorder groups controlling for cognitive level.
Results   We found that 60% of the children with FXS met criteria for autism or Pervasive Developmental Disorder – Not otherwise specified (PDD-NOS). Children with FXS with autism and PDD-NOS had lower fine motor scores than those without. However, there was no significant association between degree of motor impairment and communication and social impairments after controlling for cognitive level, indicating that cognitive level contributes to impaired motor abilities of children diagnosed with FXS and autism, more than the severity of autism symptoms.
Conclusion   children with FXS and autism are at risk for impaired motor abilities. Implications for development and intervention are discussed.     

Theory of mind deficits in children with fragile X syndrome

Background Given the consistent findings of theory of mind deficits in children with autism, it would be extremely beneficial to examine the profile of theory of mind abilities in other clinical groups such as fragile X syndrome (FXS) and Down syndrome (DS). Aim The aim of the present study was to assess whether boys with FXS are impaired in simple social situations that require them to understand their own and others’ mental states – in essence: do they have a ‘theory of mind’? Method Well-standardized tasks of theory of mind, the location change false belief task and the appearance–reality tasks were employed to examine whether any impairment might be specific to the FXS or part of a more generalized developmental deficit. Results The results suggest that children with FXS do have impairment in theory of mind that is comparable to the deficit reported in other groups with learning disabilities such as DS. However, closer inspection of the impairment between these groups revealed qualitative differences in error types (realist vs. phenomenist), suggestive of atypical development that goes beyond general cognitive delay. Conclusion The findings are discussed in terms of the teasing apart of different components of social cognition in order to identify syndrome-specific deficiencies and proficiencies.     

Adaptive skill trajectories in infants with fragile X syndrome contrasted to typical controls and infants at high risk for autism

BackgroundAdaptive behaviors are essential for optimal outcomes and independence in individuals with developmental disabilities. This study examined longitudinal trajectories of adaptive behavior in infants with fragile X syndrome (FXS), compared to typical development (TD) and infant siblings of children diagnosed with autism (ASIBs).MethodParticipants included 76 male infants (FXS = 25, ASIBs = 27, TD = 24) assessed up to 4 times between 6 and 24 months of age for a total of 215 assessments of adaptive behavior. A sample of 12 females with FXS was included for a comparative sex analysis.ResultsResults indicate that infant males with FXS displayed lower initial adaptive behavior across all domains that emerged by 9 months-of-age with slower growth rates than both comparison groups. A flat profile across the domains at 24 months was evident. Increased severity of autism symptoms was related to reduced adaptive skills at 24 months-of-age. Females with FXS displayed higher scores than males on the Socialization and Motor domains and equivalent scores on the Communication and Daily Living domains at 9 months-of-age with different rates of growth across domains.ConclusionsThis is the first study to provide evidence of etiological specificity in adaptive behavior profiles during infancy across two populations at high risk for ASD. These findings support targeted adaptive behavior interventions in young children with FXS beginning as early at 9 months of age to reduce identified deficits and the cascading impacts of these early impairments.     

Delineation of early attentional control difficulties in fragile X syndrome: focus on neurocomputational changes

Fragile X syndrome (FXS) is due to the silencing of a single X-linked gene and it is associated with striking attentional difficulties. As FXS is well characterised at the cellular level, the condition provides a unique opportunity to investigate how a genetic dysfunction can impact on the development of neurocomputational properties relevant to attention. Thirteen young boys with FXS and 13 mental-age-matched typically developing controls performed a touch-screen-based search task that manipulated the similarity between targets and distractors and their heterogeneity in size. Search speed, path and errors were recorded as multiple measures of performance. Children did not differ in overall search speed or path when searching amongst distractors, but striking error patterns distinguished children with FXS from controls. Firstly, although clear markers of previously found targets remained on screen, children with FXS perseverated on touching previous hits more than typically developing controls, consistent with the well-documented inhibitory deficits in adults with the disorder. Secondly, they could accurately discriminate single target-distractor pairs, but, when searching a complex display, they touched distractors more often than control children when distractors were similar to targets and especially so when these were infrequent, highlighting difficulties in judging relative size and allocate attentional weight independently of stimulus frequency. Thirdly, their performance was also characterised by inaccuracies in pointing, suggesting additional motor control deficits. Taken together, the findings suggest that fragile X syndrome affects the early development of multiple processes contributing to efficient attentional selection, as would be predicted from an understanding of the neurocomputational changes associated with the disorder.     

Variation in Vocal-Motor Development in Infant Siblings of Children with Autism

In this study we examined early motor, vocal, and communicative development in a group of younger siblings of children diagnosed with autism (Infant Siblings). Infant Siblings and no-risk comparison later-born infants were videotaped at home with a primary caregiver each month from 5 to 14 months, with follow-up at 18 months. As a group, Infant Siblings were delayed in the onset of early developmental milestones and spent significantly less time in a greater number of postures, suggestive of relative postural instability. In addition, they demonstrated attenuated patterns of change in rhythmic arm activity around the time of reduplicated babble onset; and they were highly likely to exhibit delayed language development at 18 months.     

A morpho-phonological Past Tense processing as a clinical marker in SLI EFL learners

ABSTRACT

The clinical marker in specific language impairment (SLI) population is the subject of considerable debate. SLI is the one of the frequently diagnosed atypical language phenomena found among early school-age children (McArthur et al., 2000; Spear-Swerling, 2006). For example, children with SLI have difficulty applying the Past Tense rule to verbs, even though they can accurately repeat phonologically similar forms of the words (Hoeffner & McClelland, 1993). In this study, I discuss the grammatical deficits in the SLI population by studying the generation of both ‘regular’ and ‘irregular’ English Past Tense forms and explain how the rates of the correct use of the ‘irregular’ versus ‘regular’ form may be considered as a clinical SLI marker. This study defines the differences in the grammatical sensitivity in the EFL learners and provides additional essential insight into SLI, in general, and its identification in the EFL learners, in particular.     

CONVERSATIONAL SKILLS OF INDIVIDUALS WITH FRAGILE-X SYNDROME: A COMPARISON WITH AUTISM AND DOWN SYNDROME

The conversational skills of 18 individuals with fragile-X syndrome (FXS) were compared with those of two other matched groups with autism and Down syndrome. The FXS group used more eliciting forms in conversation than those with Down syndrome, and also used partial self-repetition more often than the other two groups. The Down syndrome group had more speech dysfluencies than those with autism, but not more than those with FXS. The autistic group used more inappropriate phrases. Qualitative analysis of behavioral phenotype may reveal differences in communicative organization among subgroups whose retardation is based on different genotypes. In addition, analysis of verbal strategies during conversation suggests important differences between individuals with FXS and autism.     

Cognitive, language and social-cognitive skills of individuals with fragile X syndrome with and without autism

Background It is not known whether those with co‐morbid fragile X syndrome (FXS) and autism represent a distinct subtype of FXS; whether the especially severe cognitive delays seen in studies of young children with co‐morbid FXS and autism compared with those with only FXS continue into adolescence and young adulthood; and whether autism in those with FXS is ‘true autism’, i.e. reflects the same underlying problems as idiopathic autism. Method We compared the non‐verbal IQ of adolescents and young adults with co‐morbid FXS and autism (n = 10) with those with only FXS (n = 44). We then created a subsample of those with FXS only, matched on non‐verbal IQ, mental age and gender (n = 21) to the subsample of those with co‐morbid FXS and autism. We compared the two groups on measures of expressive language, receptive language (lexical, grammatical morphology and syntactic patterns), and a theory of mind task. Results Those with co‐morbid FXS and autism had lower non‐verbal IQs than those with only FXS. The participants with co‐morbid FXS and autism did not perform as well as the cognitive ability‐ and gender‐matched participants with only FXS on the three measures of receptive language or the theory of mind task; there were no differences on the expressive language measure. Conclusions Our findings support the notion that those with co‐morbid FXS and autism represent a distinct subtype of FXS, with more impairment in receptive language and theory of mind even when controlling for their lower non‐verbal IQ relative to those with only FXS. The greater cognitive impairments observed in those with co‐morbid FXS and autism continues into adolescence and young adulthood; and the autism seen in those with FXS appears to be the same as idiopathic autism.     

Teasing apart the heterogeneity of autism: Same behavior, different brains in toddlers with fragile X syndrome and autism

To examine brain volumes in substructures associated with the behavioral features of children with FXS compared to children with idiopathic autism and controls. A cross-sectional study of brain substructures was conducted at the first time-point as part of an ongoing longitudinal MRI study of brain development in FXS. The study included 52 boys between 18–42 months of age with FXS and 118 comparison children (boys with autism-non FXS, developmental-delay, and typical development). Children with FXS and autistic disorder had substantially enlarged caudate volume and smaller amygdala volume; whereas those children with autistic disorder without FXS (i.e., idiopathic autism) had only modest enlargement in their caudate nucleus volumes but more robust enlargement of their amygdala volumes. Although we observed this double dissociation among selected brain volumes, no significant differences in severity of autistic behavior between these groups were observed. This study offers a unique examination of early brain development in two disorders, FXS and idiopathic autism, with overlapping behavioral features, but two distinct patterns of brain morphology. We observed that despite almost a third of our FXS sample meeting criteria for autism, the profile of brain volume differences for children with FXS and autism differed from those with idiopathic autism. These findings underscore the importance of addressing heterogeneity in studies of autistic behavior.     

Naturalistic observations of spontaneous communication in autistic children

Thirty children with autism were observed during their everyday school activities in order to examine patterns of spontaneous communication. The forms, functions, and targets of their communication were recorded by trained observers. The prototypical communicative event consisted of a child directing a motoric form of communication toward the teacher to request something or to attract attention to himself or herself. However, communication patterns were found to vary as a function of the child's cognitive level and severity of autism. Deficits in joint attention functions were observed, and were most striking in the subgroup of children who did not use speech. Results are discussed with reference to Wetherby's (1986) model for the development of communicative functions in autistic children.     

A 'learning platform' approach to outcome measurement in fragile X syndrome: a preliminary psychometric study

Background Clinical trials of medications to alleviate the cognitive and behavioural symptoms of individuals with fragile X syndrome (FXS) are now underway. However, there are few reliable, valid and/or sensitive outcome measures available that can be directly administered to individuals with FXS. The majority of assessments employed in clinical trials may be suboptimal for individuals with intellectual disability (ID) because they require face‐to‐face interaction with an examiner, taxing administration periods, and do not provide reinforcement and/or feedback during the test. We therefore examined the psychometric properties of a new computerised ‘learning platform’ approach to outcome measurement in FXS. Method A brief computerised test, incorporated into the Discrete Trial Trainer©– a commercially available software program designed for children with ID – was administered to 13 girls with FXS, 12 boys with FXS and 15 matched ID controls aged 10 to 23 years (mental age = 4 to 12 years). The software delivered automated contingent access to reinforcement, feedback, token delivery and prompting procedures (if necessary) on each trial to facilitate responding. The primary outcome measure was the participant's learning rate, derived from the participant's cumulative record of correct responses. Results All participants were able to complete the test and floor effects appeared to be minimal. Learning rates averaged approximately five correct responses per minute, ranging from one to eight correct responses per minute in each group. Test–retest reliability of the learning rates was 0.77 for girls with FXS, 0.90 for boys with FXS and 0.90 for matched ID controls. Concurrent validity with raw scores obtained on the Arithmetic subtest of the Wechsler Intelligence Scale for Children‐III was 0.35 for girls with FXS, 0.80 for boys with FXS and 0.56 for matched ID controls. The learning rates were also highly sensitive to change, with effect sizes of 1.21, 0.89 and 1.47 in each group respectively following 15 to 20, 15‐min sessions of intensive discrete trial training conducted over 1.5 days. Conclusions These results suggest that a learning platform approach to outcome measurement could provide investigators with a reliable, valid and highly sensitive measure to evaluate treatment efficacy, not only for individuals with FXS but also for individuals with other ID.     

Abnormal Corpus Callosum Connectivity,Socio-communicative Deficits,and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore whether abnormalities of the CC were related to motor deficits, as well as social and communication deficits in children with ASD. The ASD group displayed abnormal macro and microstructure of the total CC and its subdivisions and its structural properties were related to socio-communicative deficits, but not to motor deficits in ASD. These findings advance our understanding of the contributions of the CC to ASD symptoms.     

Parenting of children with Down syndrome compared to fragile X syndrome

Children with Down syndrome (DS) and fragile X syndrome (FXS) struggle with language development. Parenting variables, such as responsiveness to children’s communication attempts (Maternal Responsivity), and techniques used to support and teach appropriate behavior (Behavior Management) are known to have a significant impact on early child development. We examined these two aspects of parenting style via coded, videotaped parent-child interactions in two groups of participants matched on child age (2–5 years) and child expressive language level: mothers of children with DS and mothers of children with FXS. The mothers differed in their use of gestures and redirecting the child’s attention. Overall, mothers in both groups of children appeared to adapt appropriately to their children’s developmental needs.     

Auditory hallucinations in pre-pubertal children

Background The aims of this study were to describe the phenomenology of auditory hallucinations in children, to establish links with DSM IV diagnoses and to explore development of the hallucinations over a 12-month period. Methods Outpatients aged 5- to 12-year-old were consecutively recruited. They were interviewed using a questionnaire investigating auditory hallucinations. DSM IV diagnoses were determined. Follow-up assessments were performed at 3, 6, 9 and 12 months. Results Ninety children were recruited. Sixteen reported auditory hallucinations. In 53% we observed children’s full recovery from hallucinations within 3 months and all of these suffered from anxiety disorders. In 30% hallucinations persisted over 12 months and all showed conduct disorders at this point in time. None was diagnosed as having schizophrenia. Conclusions Our study provides further evidence of the high prevalence of auditory hallucinations in pre-pubertal children presenting to psychiatric clinics. Two different patterns of development were seen. In one group the hallucinations seem unrelated to psychosis although they may be a manifestation of anxiety. In the second, much smaller, persistence of hallucinations appeared linked to conduct disorders.     

Autism Spectrum Disorder Symptoms in Infants with Fragile X Syndrome: A Prospective Case Series

No studies to date have prospectively examined early autism spectrum disorder (ASD) markers in infants with fragile X syndrome (FXS), who are at elevated risk for ASD. This paper describes the developmental profiles of eight infants with FXS from 9 to 24 months of age. Four meet diagnostic criteria for ASD at 24 months of age, and four do not. Trends in these case studies suggest that early social-communicative deficits differentiate infants with and without later ASD diagnoses in ways that are similar to later-born siblings of children with ASD. Repetitive behaviors and cognitive and adaptive impairments are present in all FXS infants throughout development, suggesting that these deficits reflect the general FXS phenotype and not ASD in FXS specifically.     

Socio‐cognitive understanding: a strength or weakness in Down's syndrome?

Background Social understanding is often thought to be relatively ‘protected’ in children with Down's syndrome (DS) and to underlie the outgoing personality characteristically attributed to them. This paper draws together findings from our studies of behaviours during object concept testing, generally considered a theoretically ‘pure’ measure of early cognitive ability, and from more recent work focusing on two key socio‐cognitive skills: recognising facial expressions of emotion and collaborative learning. Age range of children studied was 4 months to 18 years. Methods Using standardised hiding tasks, object concept ability was assessed cross‐sectionally and longitudinally in children with DS and in age‐ or stage‐matched typically developing (TD) children. Stability of cognitive advances was assessed and similarities/differences in developmental pathways explored. In the emotion recognition studies, the ability to distinguish six primary emotions was measured, with performance compared with that of developmentally‐matched TD children and age‐matched children with intellectual disabilities of similar severity but differing aetiology [non‐specific intellectual disability (NSID) or fragile X syndrome (FXS)]. In the collaborative learning study, the impact on sorting skills of working with a peer on a conceptually related task was measured, with outcomes compared in DS, NSID and TD child pairings. Results Evidence of counterproductive, socially‐based strategies being inappropriately applied by children with DS in learning contexts was found in both the object concept and collaborative learning studies, along with inefficient use of current cognitive and linguistic abilities. Emotion recognition weaknesses were also identified, although deficits were relative rather than absolute and individual variability was marked. Conclusions In line with emerging evidence from other research teams, findings suggest possible difficulties in some core aspects of interpersonal functioning in DS, with both qualitative and quantitative differences in how social cognition develops and is applied in learning contexts. Implications for development and for behavioural phenotype theory are briefly discussed.     

Visual Attention and Autistic Behavior in Infants with Fragile X Syndrome

Aberrant attention is a core feature of fragile X syndrome (FXS), however, little is known regarding the developmental trajectory and underlying physiological processes of attention deficits in FXS. Atypical visual attention is an early emerging and robust indictor of autism in idiopathic (non-FXS) autism. Using a biobehavioral approach with gaze direction and heart activity, we examined visual attention in infants with FXS at 9, 12, and 18?months of age with a cross-sectional comparison to 12-month-old typically developing infants. Analyses revealed lower HR variability, shallower HR decelerations, and prolonged look durations in 12-month old infants with FXS compared to typical controls. Look duration and increased latency to disengage attention were correlated with severity of autistic behavior but not mental age.