SiGe-enhanced Si capacitive modulator integration in a 300 mm silicon photonics platform for low power consumption.

The successful integration of capacitive phase shifters featuring a p-type strained SiGe layer in a 300 mm silicon photonics platform is presented. The phase shift is evaluated with a voltage swing of only 0.9 Vpp, compatible with CMOS technology. A good correlation is shown between the phase shift efficiency from 10 to 60°/mm and the capacitive oxide thickness varying from 15 to 4 nm. Corresponding insertion losses are as low as 3 dB/mm thanks to the development of low loss poly-silicon and to a careful design of the doped layers within the waveguide. The thin SiGe layer brings an additional 20% gain in efficiency due to higher hole efficiency in strained SiGe.

Low loss poly-silicon for high performance capacitive silicon modulators.

Optical properties of poly-silicon material are investigated to be integrated in new silicon photonics devices, such as capacitive modulators. Test structure fabrication is done on 300 mm wafer using LPCVD deposition: 300 nm thick amorphous silicon layers are deposited on thermal oxide, followed by solid phase crystallization anneal. Rib waveguides are fabricated and optical propagation losses measured at 1.31 µm. Physical analysis (TEM ASTAR, AFM and SIMS) are used to assess the origin of losses. Optimal deposition and annealing conditions have been defined, resulting in 400 nm-wide rib waveguides with only 9.2-10 dB/cm losses.

Disrupted behaviour in grammatical morphology in French speakers with autism spectrum disorders.

Mixed and inconsistent findings have been reported across languages concerning grammatical morphology in speakers with Autism Spectrum Disorders (ASD). Some researchers argue for a selective sparing of grammar whereas others claim to have identified grammatical deficits. The present study aimed to investigate this issue in 26 participants with ASD speaking European French who were matched on age, gender and SES to 26 participants with typical development (TD). The groups were compared regarding their productivity and accuracy of syntactic and agreement categories using the French MOR part-of-speech tagger available from the CHILDES. The groups significantly differed in productivity with respect to nouns, adjectives, determiners, prepositions and gender markers. Error analysis revealed that ASD speakers exhibited a disrupted behaviour in grammatical morphology. They made gender, tense and preposition errors and they omitted determiners and pronouns in nominal and verbal contexts. ASD speakers may have a reduced sensitivity to perceiving and processing the distributional structure of syntactic categories when producing grammatical morphemes and agreement categories. The theoretical and cross-linguistic implications of these findings are discussed.

Quality of life of adolescents with autism spectrum disorders: comparison to adolescents with diabetes.

Relationships are of great importance during adolescence. Because of their social, communication and behavioral impairments, adolescents with Asperger's syndrome (AS) or high functioning autism (HFA) probably suffer from considerable impairment of their quality of life when facing their peers in school. Nevertheless, only one recent study has been published on this subject, indicating a lower health-related quality of life in children and adolescents with autism spectrum disorders (ASD) than in healthy controls. The goals of our study were to clarify the consequences of autistic disorder without mental retardation on such adolescents' daily lives, and to consider them in comparison with the impact of a chronic somatic disease (diabetes) and with the period of adolescence itself, using the VSP-A questionnaire. Adolescents with diabetes were chosen as a comparison group because of the encumbrance of having a constant need for insulin supplementation, to be assimilated to the constant need for communicative adjustments in teenagers with ASD, and the consequences in daily life. The effects of social skill training and social support on quality of life and the appropriateness of using the VSP-A in this population were also studied. Twenty-six adolescents with AS and HFA, 44 diabetic adolescents, and 250 controls completed a self-administered and validated questionnaire on quality of life, the VSP-A. Scores for adolescents with ASD were significantly lower than those of the control and the diabetic adolescents, especially for friendships, leisure time, and affective and sexual relationships. On the other hand, better scores were obtained for the relationships with parents and teachers and for self-image. Social parameters affected the quality of life of subjects with ASD, such as having friends, regularly participating in a sport, and having the support of a school carer. For subjects with autistic spectrum disorders and without mental retardation, impairment of quality of life is significant in adolescence and young adulthood. Such adolescents are dissatisfied with their relationships, although they often have real motivation to succeed with them. Relevance of VSP-A questionnaire in these special individuals is discussed.

Early Intervention in Severe Autism: Positive Outcome Using Exchange and Development Therapy.

Early intervention programs positively affect key behaviors for children with autism spectrum disorder (ASD). However, most of these programs do not target children with severe autistic symptomatology associated with intellectual disability (ID). This study aimed to investigate the psychological and clinical outcomes of children with severe autism and ID enrolled in the Tailored and Inclusive Program for Autism-Tours (TIPA-T). The first step of the TIPA-T is the Exchange and Development Therapy (EDT): an individual neurofunctional intervention consisting of one-to-one exchanges between a child and a therapist taking place in a pared-down environment. It aims to rehabilitate psychophysiological abilities at the roots of social communication through structured sequences of "social play." Cognitive and socio-emotional skills and general development were evaluated with the Social Cognitive Evaluation Battery scale and the Brunet-Lézine Scale-Revised, respectively, before and after 9 months of intervention in 32 children with ASD and ID. Autistic symptomatology was evaluated with the Behavior Summarized Evaluation-Revised scale at five time-points in a subset of 14 children, both in individual and group settings. Statistically significant post-intervention improvements were found in cognitive and socio-emotional skills. All but one child showed improvements in at least one social domain, and 78% of children gained one level in at least four social domains. Twenty-nine children improved in cognitive domains, with 66% of children improving in at least three cognitive domains. Autistic symptomatology evaluated in one-to-one settings significantly decreased with therapy; this reduction was observed in more than 85% of children. In group settings, autistic symptomatology also decreased in more than 60% of children. Global developmental age significantly increased by 3.8 months. The TIPA-T, including EDT in particular, improves socio-emotional skills of most children with ASD and reduces autistic symptomatology, yet with heterogeneous outcomes profiles, in line with the strong heterogeneity of profiles observed in ASD. At the group level, this study highlights the benefits of the TIPA-T for children with severe autism and associated ID. Assessment of autistic core symptoms showed an improvement of social interaction, both in one-to-one and group evaluations, demonstrating the generalizability of the skills learned during the EDT.

A comparative study of cognitive and socio-emotional development in children with Rubinstein-Taybi syndrome and children with Autism Spectrum Disorder associated with a severe intellectual disability, and in young typically developing children with matched developmental ages.

BACKGROUND: Cognitive and socio-emotional profiles of children with CREBBP-related Rubinstein-Taybi syndrome (RSTS 1), children with Autism Spectrum Disorder (ASD) with severe intellectual disability and developmental ages (DA) under 24 months, and typically developing (TD) children with similar DA were compared. PARTICIPANTS: Thirty-one children with RSTS 1 (mean chronological age, CA = 59,8 months; 33-87) and thirty children with ASD, matched on CA and DA and developmental quotients (DQ), were compared to thirty TD children (CA ranged from 12 to 24 months). METHODS: Cognitive and socio-emotional developmental levels, DA and DQ were assessed with appropriated tests. RESULTS: More socio-emotional developmental similarities were observed between TD and RSTS 1 than between TD and ASD children. Clinical groups displayed similar developmental delays in cognitive (self-image, symbolic play, means-ends, and object permanence) and socio-emotional domains (language and imitation). Children with RSTS 1 exhibited higher developmental levels in behavior regulation, joint attention, affective relations, emotional expression domains, and a lower developmental level in spatial relations domain. CONCLUSIONS: Common interventions centered on symbolic play, self-image, language, and imitation for both clinical groups, and differentiated interventions centered on spatial abilities for RSTS 1 children and on social abilities for ASD could be used by caregivers were suggested.

Topography of syllable change-detection electrophysiological indices in children and adults with reading disabilities.

INTRODUCTION: Developmental dyslexia (DD) is a frequent language-based learning disorder. The predominant etiological view postulates that reading problems originate from a phonological impairment. METHOD: We studied mismatch negativity (MMN) and Late Discriminative Negativity (LDN) to syllables change in both children (n=12; 8-12 years) and young adults (n=15; 14-23 years) with DD compared with controls. RESULTS/DISCUSSION: The present study confirmed abnormal automatic discrimination of syllable changes in both children and adults with developmental dyslexia. MMN topographic, amplitude and latency group differences were evidenced, suggesting different brain mechanisms involved in elementary auditory stimulus change-detection in DD, especially in the left hemisphere. The LDN results demonstrated that the auditory disorder of temporal processing in DD children becomes more serious at late stages of information processing and that the apparent cerebral hypo reactivity to speech changes in DD actually may correspond to additional processes. The age-related differences observed in both MMN and LDN topographies, amplitudes and latency between subjects with DD and controls could indicate different developmental courses in the neural representation of basic speech sounds in good and poor readers, with a tendency to normalization with increasing age. CONCLUSION: Our results showing atypical electrophysiological concomitants of speech auditory perception in DD strongly support the hypothesis of deviant cortical organization in DD.

Incomplete Gestation has an Impact on Cognitive Abilities in Autism Spectrum Disorder.

Extreme prematurity is known as a risk factor for autism spectrum disorder (ASD). However, the association between prematurity and ASD, for children born moderately and late preterm (MLPT) and those born early term (ET), is less established. This retrospective study aimed to characterize the phenotypic characteristics (i.e. behavioral profile and cognitive abilities) of 254 children with ASD, between 3 and 15 years of age, born MLPT (19 children), ET (60 children) and full term (175 children). MLPT and ET births do not modify ASD symptomatology, but modify cognitive development. The results highlight that incomplete gestation, i.e., MLPT or ET, has a negative impact on both verbal and nonverbal cognitive abilities, in children with neurodevelopmental vulnerability.

Author Correction: 22q13 deletion syndrome: communication disorder or autism? Evidence from a specific clinical and neurophysiological phenotype.

Since the online publication of the above article, the authors have noted errors with the author list. The author names were listed as '(last name)(first name)' instead of '(first name)(last name)'.

Heterogeneities in Cognitive and Socio-Emotional Development in Children With Autism Spectrum Disorder and Severe Intellectual Disability as a Comorbidity.

Introduction: Intellectual disability (ID) is frequently associated as a comorbidity in autism spectrum disorders (ASD). This study investigated a) how similar the heterogeneity in the cognitive and socio-emotional developmental profiles was for children with ASD and ID, b) the difference between the subjects' profiles and those of typically developing children (TD) matched for developmental levels, c) the skills existing with the lowest and highest developmental levels, and d) the relationship between developmental profiles in ASD and the severity of autism, ID, and the overall developmental level. Participants: The sample was comprised of 119 children (101 boys and 18 girls) who ranged in chronological age (CA) from 21 months to 14 years (M = 5 years 2 months; SD = 2 years 6 months) with developmental levels lower than 24 months. They came from three countries (France = 40, Brazil = 40, and Algeria = 39). The control group was comprised of 40 TD children from these same countries who ranged in CA from 4 to 24 months (M = 1 year 3 months; SD = 5 months). The ASD diagnosis was carried out according to International Statistical Classification of Diseases and Related Health Problems-10th Edition (ICD-10), Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR), Diagnostic and Statistical Manual of Mental Disorders-5th ed (DSM-5) criteria and the Childhood Autism Rating Scale (CARS). Measures: Children were tested using the Social Cognitive Evaluation Battery (SCEB; Adrien, 2007) by trained psychologists from public and private institutions specialized in the diagnosis of autism and interventions in this field. The SCEB explores 16 functional abilities, in both cognitive and socio-emotional areas, and allows the calculation of domain and area developmental levels and heterogeneity indices for the global, cognitive, and socio-emotional areas. Results: Children with ASD developmental profiles show very high heterogeneity as opposed to TD children. Regardless of the country of origin, there are similarities between the heterogeneous cognitive and socio-emotional developmental profiles of the children with ASD, whose profiles are characterized by lower developmental levels of language and vocal imitation skills, and a relationship between these developmental heterogeneities and the degree of severity of autistic symptomatology, intellectual disability, and overall development level. The implications of this study are presented for clinical assessment and intervention purposes in ASD and ID.

22q13 deletion syndrome: communication disorder or autism? Evidence from a specific clinical and neurophysiological phenotype.

Phelan-McDermid syndrome is related to terminal 22q13 deletions of various sizes affecting the SHANK3 gene. In this neurodevelopmental disorder, behavioural symptoms of autism spectrum disorder (ASD) are reported in half of cases. Extensive clinical and neurophysiological characterization is lacking to understand the genotype-phenotype correlation. Eighteen patients (8 males, mean age 12.7 years, SD = 9.2) with known 22q13 deletions were fully explored with determination of deletion size, along with behavioural, language and cognitive standardized assessments. Neurophysiological indices previously reported to be altered in autism (i.e., eye tracking in a social/non-social task and auditory evoked potential mismatch) were also recorded. Thirty-nine percent met ASD clinical criteria, exceeding cut-off scores on both ADI-R (Autism Diagnosis Interview based on the period spanning 4-5 years of age) and ADOS-2 (Autism Diagnosis Observation Schedule for the current period). All patients had intellectual disability and language disability. Deletion size was significantly correlated with expressive and receptive language disability but not with ASD standardized assessment scores. Developmental Quotient tended to be lower in patients with the largest deletions. Using Eye Tracking, smaller pupil size, which is typically described in ASD, was not observed in these patients. Furthermore, atypical shortened latency of mismatch negativity response previously reported in ASD was not observed, whereas the N250 pattern, related to language, was affected. Language disability combined with cognitive deficits may lead to autistic behavioural symptoms, but with different neurophysiological networks compared to typical autism. These results highlight the indication for early speech therapy rather than intensive autism programme to treat these patients.

Impairment of a cortical event-related desynchronisation during a bimanual load-lifting task in children with autistic disorder.

In autism, the abilities of communication are affected, associated with abnormalities of cognitive, sensorial and motor development. In a previous study based on a load-lifting task, we showed impairment of anticipation in children with autism as evidenced by kinematics and eletromyographic recordings [Neurosci. Lett. 348 (2003) 17]. In the present study, we assessed the cortical counterparts of the use of anticipatory postural adjustments in a group of control children and in a group of children with autism. The tasks required maintaining a stable forearm position despite imposed or voluntary lifting of an object placed either on the controlateral forearm or on a support. We investigated the differences between the two groups of children on the Event-Related Desynchronisation (ERD) which precedes movement onset in adults [Electroencephalogr. Clin. Neurophysiol. 46 (1979) 138]. Electroencephalogram (EEG) power evolution of a 6-8-Hz frequency band was averaged before and after imposed or voluntary movement onset. EEG reactivity of control and autistic children did not differ during the imposed unloading condition, but significant differences appeared in the voluntary unloading situations. Before lifting the object, control children showed an ERD above the left motor areas. An ERD also occurred above the right motor areas when the object was placed on their forearm. This indicates that the ERD can also translate the use of anticipatory postural adjustments. By contrast, children with autism did not show an ERD in the two voluntary situations. This suggests a central deficit of anticipation in both postural and motor control in children with autism.

Candidate electrophysiological endophenotypes of hyper-reactivity to change in autism.

Although resistance to change is a main feature of autism, the brain processes underlying this aspect of the disorder remain poorly understood. The aims of this study were to examine neural basis of auditory change-detection in children with autism spectrum disorders (ASD; N = 27) through electrophysiological patterns (MMN, P3a) and to test whether these are quantitatively related to intolerance of change (using the BSE-R scale). ASD displayed significantly shorter MMN latency and larger P3a than controls, indicating a greater tendency to switch attention to deviant events. These electrophysiological abnormalities were significantly more marked in children who displayed greater difficulties in tolerating change. The atypical neurophysiological mechanism of change perception identified might thus be associated with one of the hallmark behavioural manifestations of autism.

The social cognitive evaluation battery for children with autism: a new tool for the assessment of cognitive and social development in children with autism spectrum disorders.

The Social Cognitive Evaluation Battery (SCEB) is a new instrument for the psychological evaluation of children with autism. The battery consists of 16 scales that measure different cognitive and socioemotional functions. This study reports the results of a reliability analysis and some elements of validation. Analyses are based on the observed performance of 100 children with autism and a convenience sample of 35 normal children. Validation is based on the examination of the structure of the relations between the 16 scale scores of the SCEB, their relations with other measurements, the correspondence between the theoretical developmental ages, and the observed chronological ages and the SCEB's sensitivity to specific disorders. The results show that this new instrument is useful and relevant for the psychological assessment of children with autism.

X-linked mental retardation and autism are associated with a mutation in the NLGN4 gene, a member of the neuroligin family.

A large French family including members affected by nonspecific X-linked mental retardation, with or without autism or pervasive developmental disorder in affected male patients, has been found to have a 2-base-pair deletion in the Neuroligin 4 gene (NLGN4) located at Xp22.33. This mutation leads to a premature stop codon in the middle of the sequence of the normal protein and is thought to suppress the transmembrane domain and sequences important for the dimerization of neuroligins that are required for proper cell-cell interaction through binding to beta-neurexins. As the neuroligins are mostly enriched at excitatory synapses, these results suggest that a defect in synaptogenesis may lead to deficits in cognitive development and communication processes. The fact that the deletion was present in both autistic and nonautistic mentally retarded males suggests that the NLGN4 gene is not only involved in autism, as previously described, but also in mental retardation, indicating that some types of autistic disorder and mental retardation may have common genetic origins.