Pubmed du 17/06/09

Pubmed du jour

2009-06-17 12:03:50

1. Auyeung B, Wheelwright S, Allison C, Atkinson M, Samarawickrema N, Baron-Cohen S. {{The Children’s Empathy Quotient and Systemizing Quotient: Sex Differences in Typical Development and in Autism Spectrum Conditions}}. {J Autism Dev Disord};2009 (Jun 17)

Children’s versions of the Empathy Quotient (EQ-C) and Systemizing Quotient (SQ-C) were developed and administered to n = 1,256 parents of typically developing children, aged 4-11 years. Both measures showed good test-retest reliability and high internal consistency. As predicted, girls scored significantly higher on the EQ-C, and boys scored significantly higher on the SQ-C. A further sample of n = 265 children with Autism Spectrum Conditions (ASC) scored significantly lower on the EQ-C, and significantly higher on the SQ-C, compared to typical boys. Empathy and systemizing in children show similar patterns of sex differences to those observed in adults. Children with ASC tend towards a ‘hyper-masculinized’ profile, irrespective of sex.

2. Baron-Cohen S, Ashwin E, Ashwin C, Tavassoli T, Chakrabarti B. {{Talent in autism: hyper-systemizing, hyper-attention to detail and sensory hypersensitivity}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1377-1383.

We argue that hyper-systemizing predisposes individuals to show talent, and review evidence that hyper-systemizing is part of the cognitive style of people with autism spectrum conditions (ASC). We then clarify the hyper-systemizing theory, contrasting it to the weak central coherence (WCC) and executive dysfunction (ED) theories. The ED theory has difficulty explaining the existence of talent in ASC. While both hyper-systemizing and WCC theories postulate excellent attention to detail, by itself excellent attention to detail will not produce talent. By contrast, the hyper-systemizing theory argues that the excellent attention to detail is directed towards detecting ‘if p, then q’ rules (or [input-operation-output] reasoning). Such law-based pattern recognition systems can produce talent in systemizable domains. Finally, we argue that the excellent attention to detail in ASC is itself a consequence of sensory hypersensitivity. We review an experiment from our laboratory demonstrating sensory hypersensitivity detection thresholds in vision. We conclude that the origins of the association between autism and talent begin at the sensory level, include excellent attention to detail and end with hyper-systemizing.

3. Cardinal R. {{Outsider Art and the autistic creator}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1459-1466.

Outsider Art (art brut) is defined as a mode of original artistic expression which thrives on its independence, shunning the public sphere and the art market. Such art can be highly idiosyncratic and secretive, and reflects the individual creator’s attempt to construct a coherent, albeit strange, private world. Certain practitioners of what may be termed autistic art are examined in the light of this definition; their work is considered as evidence not of a medical condition but of an expressive intentionality entirely worthy of the interest of those drawn to the aesthetic experience.

4. Casanova M, Trippe J. {{Radial cytoarchitecture and patterns of cortical connectivity in autism}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1433-1436.

To explain the pattern of preserved and superior abilities found in autism spectrum disorders, a hypothesis has emerged, which assumes that there is a developmental bias towards the formation of short-range connections. This would result in excessive activity and overconnectivity within susceptible local networks. These networks might become partially isolated and acquire novel functional properties. In turn, this would affect the formation of long-range circuits and systems governing top-down control and integration. Despite many tantalizing clues, mechanisms relating pathogenesis and altered cell function to the ‘disconnection’ of integrative and focal activity remain obscure. However, recent post-mortem studies of brains of individuals with autism have shown characteristic differences in the morphometry of radial cell minicolumns, which add credence to the connectivity hypothesis.

5. Dodds L, Spencer A, Shea S, Fell D, Armson BA, Allen AC, Bryson S. {{Validity of autism diagnoses using administrative health data}}. {Chronic Dis Can};2009;29(3):102-107.

It is necessary to monitor autism prevalence in order to plan education support and health services for affected children. This study was conducted to assess the accuracy of administrative health databases for autism diagnoses. Three administrative health databases from the province of Nova Scotia were used to identify diagnoses of autism spectrum disorders (ASD): the Hospital Discharge Abstract Database, the Medical Services Insurance Physician Billings Database and the Mental Health Outpatient Information System database. Seven algorithms were derived from combinations of requirements for single or multiple ASD claims from one or more of the three administrative databases. Diagnoses made by the Autism Team of the IWK Health Centre, using state-of-the-art autism diagnostic schedules, were compared with each algorithm, and the sensitivity, specificity and C-statistic (i.e. a measure of the discrimination ability of the model) were calculated. The algorithm with the best test characteristics was based on one ASD code in any of the three databases (sensitivity=69.3%). Sensitivity based on an ASD code in either the hospital or the physician billing databases was 62.5%. Administrative health databases are potentially a cost efficient source for conducting autism surveillance, especially when compared to methods involving the collection of new data. However, additional data sources are needed to improve the sensitivity and accuracy of identifying autism in Canada.

6. Draaisma D. {{Stereotypes of autism. Philos Trans R Soc Lond B Biol Sci}};2009 (May 27);364(1522):1475-1480.

In their landmark papers, both Kanner and Asperger employed a series of case histories to shape clinical insight into autistic disorders. This way of introducing, assessing and representing disorders has disappeared from today’s psychiatric practice, yet it offers a convincing model of the way stereotypes may build up as a result of representations of autism. Considering that much of what society at large learns on disorders on the autism spectrum is produced by representations of autism in novels, TV-series, movies or autobiographies, it will be of vital importance to scrutinize these representations and to check whether or not they are, in fact, misrepresenting autism. In quite a few cases, media representations of talent and special abilities can be said to have contributed to a harmful divergence between the general image of autism and the clinical reality of the autistic condition.

7. Drake JE, Winner E. {{Precocious realists: perceptual and cognitive characteristics associated with drawing talent in non-autistic children}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1449-1458.

A local processing bias in the block design task and in drawing strategy has been used to account for realistic drawing skill in individuals with autism. We investigated whether the same kind of local processing bias is seen in typically developing children with unusual skill in realistic graphic representation. Forty-three 5-11-year-olds who drew a still life completed a version of the block design task in both standard and segmented form, were tested for their memory for the block design items, and were given the Kaufmann Brief Intelligence Test-II. Children were classified as gifted, moderately gifted or typical on the basis of the level of realism in their drawings. Similar to autistic individuals, the gifted group showed a local processing bias in the block design task. But unlike autistic individuals, the gifted group showed a global advantage in the visual memory task and did not use a local drawing strategy; in addition, their graphic realism skill was related to verbal IQ. Differences in the extent of local processing bias in autistic and typically developing children with drawing talent are discussed.

8. Grandin T. {{How does visual thinking work in the mind of a person with autism? A personal account}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1437-1442.

My mind is similar to an Internet search engine that searches for photographs. I use language to narrate the photo-realistic pictures that pop up in my imagination. When I design equipment for the cattle industry, I can test run it in my imagination similar to a virtual reality computer program. All my thinking is associative and not linear. To form concepts, I sort pictures into categories similar to computer files. To form the concept of orange, I see many different orange objects, such as oranges, pumpkins, orange juice and marmalade. I have observed that there are three different specialized autistic/Asperger cognitive types. They are: (i) visual thinkers such as I who are often poor at algebra, (ii) pattern thinkers such as Daniel Tammet who excel in math and music but may have problems with reading or writing composition, and (iii) verbal specialists who are good at talking and writing but they lack visual skills.

9. Hacking I. {{Autistic autobiography}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1467-1473.

Autism narratives are not just stories or histories, describing a given reality. They are creating the language in which to describe the experience of autism, and hence helping to forge the concepts in which to think autism. This paper focuses on a series of autobiographies that began with Grandin’s Emergence. These are often said to show us autism from the ‘inside’. The paper proposes that instead they are developing ways to describe experience for which there is little pre-existing language. Wittgenstein has many well-known aphorisms about how we understand other people directly, without inference. They condense what he had found in Wolfgang Kohler’s Gestalt Psychology. These phenomena of direct understanding what other people are doing are, Kohler wrote, ‘the common property and practice of mankind’. They are not the common property and practice of people with autism. Ordinary language is rich in age-old ways to describe what others are thinking, feeling and so forth. Kohler’s phenomena are the bedrock on which such language rests. There is no such discourse for autism, because Kohler’s phenomena are absent. But a new discourse is being made up right now, i.e. ways of talking for which the autobiographies serve as working prototypes.

10. Happe F, Frith U. {{The beautiful otherness of the autistic mind}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1346-1350.

11. Happe F, Vital P. {{What aspects of autism predispose to talent?}} {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1369-1375.

In this paper, we explore the question, why are striking special skills so much more common in autism spectrum conditions (ASC) than in other groups? Current cognitive accounts of ASC are briefly reviewed in relation to special skills. Difficulties in ‘theory of mind’ may contribute to originality in ASC, since individuals who do not automatically ‘read other minds’ may be better able to think outside prevailing fashions and popular theories. However, originality alone does not confer talent. Executive dysfunction has been suggested as the ‘releasing’ mechanism for special skills in ASC, but other groups with executive difficulties do not show raised incidence of talents. Detail-focused processing bias (‘weak coherence’, ‘enhanced perceptual functioning’) appears to be the most promising predisposing characteristic, or ‘starting engine’, for talent development. In support of this notion, we summarize data from a population-based twin study in which parents reported on their 8-year-olds’ talents and their ASC-like traits. Across the whole sample, ASC-like traits, and specifically ‘restricted and repetitive behaviours and interests’ related to detail focus, were more pronounced in children reported to have talents outstripping older children. We suggest that detail-focused cognitive style predisposes to talent in savant domains in, and beyond, autism spectrum disorders.

12. Heaton P. {{Assessing musical skills in autistic children who are not savants}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1443-1447.

Descriptions of autistic musical savants suggest that they possess extraordinary skills within the domain. However, until recently little was known about the musical skills and potential of individuals with autism who are not savants. The results from these more recent studies investigating music perception, cognition and learning in musically untrained children with autism have revealed a pattern of abilities that are either enhanced or spared. For example, increased sensitivity to musical pitch and timbre is frequently observed, and studies investigating perception of musical structure and emotions have consistently failed to reveal deficits in autism. While the phenomenon of the savant syndrome is of considerable theoretical interest, it may have led to an under-consideration of the potential talents and skills of that vast majority of autistic individuals, who do not meet savant criteria. Data from empirical studies show that many autistic children possess musical potential that can and should be developed.

13. Howlin P, Goode S, Hutton J, Rutter M. {{Savant skills in autism: psychometric approaches and parental reports}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1359-1367.

Most investigations of savant skills in autism are based on individual case reports. The present study investigated rates and types of savant skills in 137 individuals with autism (mean age 24 years). Intellectual ability ranged from severe intellectual impairment to superior functioning. Savant skills were judged from parental reports and specified as ‘an outstanding skill/knowledge clearly above participant’s general level of ability and above the population norm’. A comparable definition of exceptional cognitive skills was applied to Wechsler test scores–requiring a subtest score at least 1 standard deviation above general population norms and 2 standard deviations above the participant’s own mean subtest score. Thirty-nine participants (28.5%) met criteria for either a savant skill or an exceptional cognitive skill: 15 for an outstanding cognitive skill (most commonly block design); 16 for a savant skill based on parental report (mostly mathematical/calculating abilities); 8 met criteria for both a cognitive and parental rated savant skill. One-third of males showed some form of outstanding ability compared with 19 per cent of females. No individual with a non-verbal IQ below 50 met criteria for a savant skill and, contrary to some earlier hypotheses, there was no indication that individuals with higher rates of stereotyped behaviours/interests were more likely to demonstrate savant skills.

14. Landry O, Mitchell PL, Burack JA. {{Orienting of visual attention among persons with autism spectrum disorders: reading versus responding to symbolic cues}}. {J Child Psychol Psychiatry};2009 (Jul);50(7):862-870.

BACKGROUND: Are persons with autism spectrum disorders (ASD) slower than typically developing individuals to read the meaning of a symbolic cue in a visual orienting paradigm? METHODS: Participants with ASD (n = 18) and performance mental age (PMA) matched typically developing children (n = 16) completed two endogenous orienting conditions in which the cue exposure time and response preparation time were manipulated within a consistent series of cue-target stimulus onset asynchronies (SOAs). RESULTS: Participants with ASD displayed facilitation effects at all SOAs, whereas typically developing children displayed facilitation effects only at shorter SOAs. The magnitude of the facilitation effect was greater for the group with ASD at 400ms SOA. Both groups showed similar effects of condition, with similar patterns of facilitation in both conditions. CONCLUSION: Persons with ASD were not slower to read the symbolic cue, as the effect was elicited by brief cues within longer SOAs before target onset. The participants with ASD were also less efficient in using the predictability of the cues to guide responding. The difficulties of participants with ASD on endogenous orienting occur at the response selection level, not the perceptual level.

15. Pickles A, Simonoff E, Conti-Ramsden G, Falcaro M, Simkin Z, Charman T, Chandler S, Loucas T, Baird G. {{Loss of language in early development of autism and specific language impairment}}. {J Child Psychol Psychiatry};2009 (Jul);50(7):843-852.

BACKGROUND: Several authors have highlighted areas of overlap in symptoms and impairment among children with autism spectrum disorder (ASD) and children with specific language impairment (SLI). By contrast, loss of language and broadly defined regression have been reported as relatively specific to autism. We compare the incidence of language loss and language progression of children with autism and SLI. METHODS: We used two complementary studies: the Special Needs and Autism Project (SNAP) and the Manchester Language Study (MLS) involving children with SLI. This yielded a combined sample of 368 children (305 males and 63 females) assessed in late childhood for autism, history of language loss, epilepsy, language abilities and nonverbal IQ. RESULTS: language loss occurred in just 1% of children with SLI but in 15% of children classified as having autism or autism spectrum disorder. Loss was more common among children with autism rather than milder ASD and is much less frequently reported when language development is delayed. For children who lost language skills before their first phrases, the phrased speech milestone was postponed but long-term language skills were not significantly lower than children with autism but without loss. For the few who experienced language loss after acquiring phrased speech, subsequent cognitive performance is more uncertain. CONCLUSIONS: Language loss is highly specific to ASD. The underlying developmental abnormality may be more prevalent than raw data might suggest, its possible presence being hidden for children whose language development is delayed.

16. Plaisted Grant K, Davis G. {{Perception and apperception in autism: rejecting the inverse assumption}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1393-1398.

In addition to those with savant skills, many individuals with autism spectrum conditions (ASCs) show superior perceptual and attentional skills relative to the general population. These superior skills and savant abilities raise important theoretical questions, including whether they develop as compensations for other underdeveloped cognitive mechanisms, and whether one skill is inversely related to another weakness via a common underlying neurocognitive mechanism. We discuss studies of perception and visual processing that show that this inverse hypothesis rarely holds true. Instead, they suggest that enhanced performance is not always accompanied by a complementary deficit and that there are undeniable difficulties in some aspects of perception that are not related to compensating strengths. Our discussion emphasizes the qualitative differences in perceptual processing revealed in these studies between individuals with and without ASCs. We argue that this research is important not only in furthering our understanding of the nature of the qualitative differences in perceptual processing in ASCs, but can also be used to highlight to society at large the exceptional skills and talent that individuals with ASCs are able to contribute in domains such as engineering, computing and mathematics that are highly valued in industry.

17. Soulieres I, Dawson M, Samson F, Barbeau EB, Sahyoun CP, Strangman GE, Zeffiro TA, Mottron L. {{Enhanced visual processing contributes to matrix reasoning in autism}}. {Hum Brain Mapp};2009 (Jun 15)

Recent behavioral investigations have revealed that autistics perform more proficiently on Raven’s Standard Progressive Matrices (RSPM) than would be predicted by their Wechsler intelligence scores. A widely-used test of fluid reasoning and intelligence, the RSPM assays abilities to flexibly infer rules, manage goal hierarchies, and perform high-level abstractions. The neural substrates for these abilities are known to encompass a large frontoparietal network, with different processing models placing variable emphasis on the specific roles of the prefrontal or posterior regions. We used functional magnetic resonance imaging to explore the neural bases of autistics’ RSPM problem solving. Fifteen autistic and eighteen non-autistic participants, matched on age, sex, manual preference and Wechsler IQ, completed 60 self-paced randomly-ordered RSPM items along with a visually similar 60-item pattern matching comparison task. Accuracy and response times did not differ between groups in the pattern matching task. In the RSPM task, autistics performed with similar accuracy, but with shorter response times, compared to their non-autistic controls. In both the entire sample and a subsample of participants additionally matched on RSPM performance to control for potential response time confounds, neural activity was similar in both groups for the pattern matching task. However, for the RSPM task, autistics displayed relatively increased task-related activity in extrastriate areas (BA18), and decreased activity in the lateral prefrontal cortex (BA9) and the medial posterior parietal cortex (BA7). Visual processing mechanisms may therefore play a more prominent role in reasoning in autistics. Hum Brain Mapp, 2009. (c) 2009 Wiley-Liss, Inc.

18. Wallace GL, Happe F, Giedd JN. {{A case study of a multiply talented savant with an autism spectrum disorder: neuropsychological functioning and brain morphometry}}. {Philos Trans R Soc Lond B Biol Sci};2009 (May 27);364(1522):1425-1432.

Neuropsychological functioning and brain morphometry in a savant (case GW) with an autism spectrum disorder (ASD) and both calendar calculation and artistic skills are quantified and compared with small groups of neurotypical controls. Good memory, mental calculation and visuospatial processing, as well as (implicit) knowledge of calendar structure and ‘weak’ central coherence characterized the cognitive profile of case GW. Possibly reflecting his savant skills, the superior parietal region of GW’s cortex was the only area thicker (while areas such as the superior and medial prefrontal, middle temporal and motor cortices were thinner) than that of a neurotypical control group. Taken from the perspective of learning/practice-based models, skills in domains (e.g. calendars, art, music) that capitalize upon strengths often associated with ASD, such as detail-focused processing, are probably further enhanced through over-learning and massive exposure, and reflected in atypical brain structure.