Pubmed du 21/03/09

Pubmed du jour

2009-03-21 12:03:50

1. {{Special report: early intensive behavioral intervention based on applied behavior analysis among children with autism spectrum disorders}}. {Technol Eval Cent Asses Program Exec Summ};2009 (Feb);23(9):1-5.

2. Elsabbagh M, Volein A, Holmboe K, Tucker L, Csibra G, Baron-Cohen S, Bolton P, Charman T, Baird G, Johnson MH. {{Visual orienting in the early broader autism phenotype: Disengagement and facilitation}}. {J Child Psychol Psychiatry};2009 (Feb 27)

Background: Recent studies of infant siblings of children diagnosed with autism have allowed for a prospective approach to examine the emergence of symptoms and revealed behavioral differences in the broader autism phenotype within the early years. In the current study we focused on a set of functions associated with visual attention, previously reported to be atypical in autism. Method: We compared performance of a group of 9-10-month-old infant siblings of children with autism to a control group with no family history of autism on the ‘gap-overlap task’, which measures the cost of disengaging from a central stimulus in order to fixate a peripheral one. Two measures were derived on the basis of infants’ saccadic reaction times. The first is the Disengagement effect, which measures the efficiency of disengaging from a central stimulus to orient to a peripheral one. The second was a Facilitation effect, which arises when the infant is cued by a temporal gap preceding the onset of the peripheral stimulus, and would orient faster after its onset. Results and conclusion: Infant siblings of children with autism showed longer Disengagement latencies as well as less Facilitation relative to the control group. The findings are discussed in relation to how differences in visual attention may relate to characteristics observed in autism and the broader phenotype.

3. Henderson HA, Zahka NE, Kojkowski NM, Inge AP, Schwartz CB, Hileman CM, Coman DC, Mundy PC. {{Self-referenced memory, social cognition, and symptom presentation in autism}}.{ J Child Psychol Psychiatry};2009 (Feb 26)

Background: We examined performance on a self-referenced memory (SRM) task for higher-functioning children with autism (HFA) and a matched comparison group. SRM performance was examined in relation to symptom severity and social cognitive tests of mentalizing. Method: Sixty-two children (31 HFA, 31 comparison; 8-16 years) completed a SRM task in which they read a list of words and decided whether the word described something about them, something about Harry Potter, or contained a certain number of letters. They then identified words that were familiar from a longer list. Dependent measures were memory performance (d’) in each of the three encoding conditions as well as a self-memory bias score (d’ self-d’ other). Children completed The Strange Stories Task and The Children’s Eyes Test as measures of social cognition. Parents completed the SCQ and ASSQ as measures of symptom severity. Results: Children in the comparison sample showed the standard SRM effect in which they recognized significantly more self-referenced words relative to words in the other-referenced and letter conditions. In contrast, HFA children showed comparable rates of recognition for self- and other-referenced words. For all children, SRM performance improved with age and enhanced SRM performance was related to lower levels of social problems. These associations were not accounted for by performance on the mentalizing tasks. Conclusions: Children with HFA did not show the standard enhanced processing of self- vs. other-relevant information. Individual differences in the tendency to preferentially process self-relevant information may be associated with social cognitive processes that serve to modify the expression of social symptoms in children with autism.

4. Honda H, Shimizu Y, Nitto Y, Imai M, Ozawa T, Iwasa M, Shiga K, Hira T. {{Extraction and Refinement Strategy for detection of autism in 18-month-olds: a guarantee of higher sensitivity and specificity in the process of mass screening}}. {J Child Psychol Psychiatry};2009 (Feb 27)

Background: For early detection of autism, it is difficult to maintain an efficient level of sensitivity and specificity based on observational data from a single screening. The Extraction and Refinement (E&R) Strategy utilizes a public children’s health surveillance program to produce maximum efficacy in early detection of autism. In the extraction stage, all cases at risk of childhood problems, including developmental abnormality, are identified; in the refinement stage, cases without problems are excluded, leaving only cases with conclusive diagnoses. Methods: The city of Yokohama, Japan, conducts a routine child health surveillance program for children at 18 months in which specialized public health nurses administer YACHT-18 (Young Autism and other developmental disorders CHeckup Tool), a screening instrument to identify children at risk for developmental disorders. Children who screen positive undergo further observation, and those without disorders are subsequently excluded. To study the efficacy of early detection procedures for developmental disorders, including autism, 2,814 children born in 1988, examined at 18 months of age, and not already receiving treatment for diseases or disorders were selected. Results: In the extraction stage, 402 (14.3%) children were identified for follow-up. In the refinement stage, 19 (.7%) of these were referred to the Yokohama Rehabilitation Center and diagnosed with developmental disorders. The extraction stage produced four false negatives, bringing total diagnoses of developmental disorders to 23 (.8%) – including 5 with autistic disorder and 9 with pervasive developmental disorder – not otherwise specified (PDDNOS). Sensitivity was 60% for autistic disorder and 82.6% for developmental disorders. Specificity for developmental disorders rose to 100% with the E&R Strategy. Picture cards used in YACHT-18 provided a finer screen that excluded some false positive cases. Conclusions: An extraction and refinement methodology utilizing child health surveillance programs achieve high efficacy for early detection of autism.

5. Norbury CF, Brock J, Cragg L, Einav S, Griffiths H, Nation K. {{Eye-movement patterns are associated with communicative competence in autistic spectrum disorders}}.{ J Child Psychol Psychiatry};2009 (Feb 27)

Background: Investigations using eye-tracking have reported reduced fixations to salient social cues such as eyes when participants with autism spectrum disorders (ASD) view social scenes. However, these studies have not distinguished different cognitive phenotypes. Methods: The eye-movements of 28 teenagers with ASD and 18 typically developing peers were recorded as they watched videos of peers interacting in familiar situations. Within ASD, we contrasted the viewing patterns of those with and without language impairments. The proportion of time spent viewing eyes, mouths and other scene details was calculated, as was latency of first fixation to eyes. Finally, the association between viewing patterns and social-communicative competence was measured. Results: Individuals with ASD and age-appropriate language abilities spent significantly less time viewing eyes and were slower to fixate the eyes than typically developing peers. In contrast, there were no differences in viewing patterns between those with language impairments and typically developing peers. Eye-movement patterns were not associated with social outcomes for either language phenotype. However, increased fixations to the mouth were associated with greater communicative competence across the autistic spectrum. Conclusions: Attention to both eyes and mouths is important for language development and communicative competence. Differences in fixation time to eyes may not be sufficient to disrupt social competence in daily interactions. A multiple cognitive deficit model of ASD, incorporating different language phenotypes, is advocated.

6. Ramachandran R, Mitchell P, Ropar D. {{Do individuals with autism spectrum disorders infer traits from behavior?}} {J Child Psychol Psychiatry};2009 (Feb 26)

Background: Traits and mental states are considered to be inter-related parts of theory of mind. Attribution research demonstrates the influential role played by traits in social cognition. However, there has been little investigation into how individuals with autism spectrum disorders (ASD) understand traits. Method: The ability of individuals with ASD to infer traits from descriptions of behavior was investigated by asking participants to read trait-implying sentences and then to choose one of two words that best related to the sentence. Results: In Experiment 1, individuals with ASD performed similarly to matched controls in being faster at choosing the trait in comparison to the semantic associate of one of the words in the sentence. The results from Experiments 1 and 2 provided converging evidence in suggesting that inferring traits from textual descriptions of behavior occurs with relatively little effort. The results of Experiment 3 suggested that making trait inferences took priority over inferring actions or making semantic connections between words. Conclusions: Individuals with ASD infer traits from descriptions of behavior effortlessly and spontaneously. The possibility of trait inference being a spared socio-cognitive function in autism is discussed.

7. Smith CJ, Lang CM, Kryzak L, Reichenberg A, Hollander E, Silverman JM. {{Familial associations of intense preoccupations, an empirical factor of the restricted, repetitive behaviors and interests domain of autism}}. {J Child Psychol Psychiatry};2009 (Feb 26)

Background: Clinical heterogeneity of autism likely hinders efforts to find genes associated with this complex psychiatric disorder. Some studies have produced promising results by restricting the sample according to the expression of specific familial factors or components of autism. Previous factor analyses of the restricted, repetitive behaviors and interest (RRBI) domain of autism have consistently identified a two-factor model that explains a moderate amount of variance. The identification of additional factors may explain more variance in the RRBI domain and provide an additional component of autism that may help in the identification of underlying genetic association. Methods: We conducted factor analyses of RRBI symptoms with a sample that included verbal subjects meeting full criteria for autism aged 5 to 22 years (n = 245). Among affected sibling pairs (n = 126) we examined the familial aggregation of the identified factors. We also examined the associations of the factors with autism-related personality traits in fathers and mothers (n = 50). Results: The previously identified two-factor model – insistence on sameness (IS) and repetitive stereotypic motor behaviors (RSMB) – was replicated in our sample. Next, a second factor analysis that included the item for verbal rituals resulted in a four-factor model – IS, ‘simple’ RSMB, ‘complex’ RSMB, and a fourth factor including symptoms associated with intense preoccupations (IP). Of these four, both IS and IP were significantly familial among affected siblings, but only IP was significantly correlated with the broader autism phenotype traits of rigidity and aloofness in fathers. Conclusions: The results support previous evidence for the IS factor, its familiality, and the identification of IP as an additional strong candidate trait for genetic studies of autism.

8. Whitney ER, Kemper TL, Rosene DL, Bauman ML, Blatt GJ. {{Density of cerebellar basket and stellate cells in autism: Evidence for a late developmental loss of Purkinje cells}}. {J Neurosci Res};2009 (Mar 19)

Alterations in the cerebellum have been described as a neuropathological feature of autism. Although numerous studies have focused on the Purkinje cell (PC), the projection neuron of the cerebellar cortex, PC function is critically dependent on their innervation by the GABAergic basket cells (BCs) and stellate cells (SCs) in the cerebellar molecular layer. The present study was designed to determine whether there are differences in the packing density of these inhibitory interneurons or whether the ratio of these interneurons to PCs differs in autistic and age-matched control brains. The GABAergic interneurons were identified by using immunohistochemistry for parvalbumin (PV) in serial sections from the posterior cerebellar lobe of six autistic and four control brains and counted using stereological principles. Prior PC counts in the same area on adjacent sections (Whitney et al., 2008) were available and were used to calculate the number of BCs and SCs per PC. In this sample of brains, no statistically significant difference was detected between the autistic and the control groups in the density of BCs or SCs (P = 0.44 and P = 0.84, respectively) or in the number of BCs or SCs per PC (P = 0.47 and P = 0.44, respectively). The preservation of BCs and SCs, in the presence of the reduced PC numbers as found in at least two, and possibly three, of these six autistic cases (Whitney et al., 2008) suggests that PCs were generated, migrated to their proper location in the PC layer, and subsequently died in the autistic cases that showed a reduction in PCs. (c) 2009 Wiley-Liss, Inc.