John Swettenham

Infants with Autism: An Investigation of Empathy, Pretend Play, Joint Attention, and Imitation.

Systematic studies of infants with autism have not been previously carried out. Taking advantage of a new prospective screening instrument for autism in infancy (S. Baron-Cohen et al., 1996), the present study found that, compared with developmentally delayed and normally developing children, 20-month-old children with autism were specifically impaired on some aspects of empathy, joint attention, and imitation. Infants with autism failed to use social gaze in the empathy and joint attention tasks. Both the infants with autism and the infants with developmental delay demonstrated functional play, but very few participants in either group produced spontaneous pretend play. In the developmental delay group, but not the autism group, pretend play was shown following prompting. The implications of these findings for developmental accounts of autism and for the early diagnosis of the disorder are discussed.

A screening instrument for autism at 18 months of age: a 6-year follow-up study

OBJECTIVESnA population of 16,235 children aged 18 months was screened using the Checklist for Autism in Toddlers (CHAT) to identify childhood autism (CA). Two further screening procedures were conducted at age 3 and 5 years. The population was followed up at age 7 years in order to establish the sensitivity, specificity, and positive predictive value of the instrument.nnnMETHODnA brief checklist assessing joint attention and pretend play behaviors was administered by primary health care practitioners when the children were 18 months old. Follow-up methods included screening through parents and health practitioners and checking medical and educational records.nnnRESULTSnNineteen cases of CA were successfully identified by the CHAT at 18 months. At follow-up a total of 50 cases of CA were identified via all surveillance methods. Thus, the CHAT has a sensitivity of 38% and a specificity of 98% for identifying CA. The positive predictive value of the instrument was maximized by concentration on the highest-risk group. Repeated screening 1 month later increased the positive predictive value to 75% for identification of CA but reduced the sensitivity to 20%, although the specificity was close to 100%. The screen also identified cases of pervasive developmental disorder as well as children with language and other developmental disorders.nnnCONCLUSIONSnThe CHAT can be used to identify cases of autism and related pervasive developmental disorders at 18 months of age. It is emphasized that the CHAT is not a diagnostic instrument but can identify potential cases of autism spectrum disorders for a full diagnostic assessment.

Autism Spectrum Disorders at 20 and 42 Months of Age: Stability of Clinical and ADI‐R Diagnosis

The association between, and stability of, clinical diagnosis and diagnosis derived from the Autism Diagnostic Interview-Revised (ADI-R; Lord, Rutter, & Le Couteur, 1994) was examined in a sample of prospectively identified children with childhood autism and other pervasive developmental disorders assessed at the age of 20 months and 42 months. Clinical diagnosis of autism was stable, with all children diagnosed with childhood autism at age 20 months receiving a diagnosis of childhood autism or a related pervasive developmental disorder (PDD) at age 42 months. Clinical diagnosis of childhood autism was also reasonably sensitive, with all children who went on to receive a clinical diagnosis of childhood autism at 42 months being identified as having autism or PDD at 20 months. However, clinical diagnosis for PDD and Aspergers syndrome lacked sensitivity at 20 months, with several children who subsequently received these diagnoses at 42 months receiving diagnoses of language disorder or general developmental delay, as well as in two cases being considered clinically normal, at the earlier timepoint. The ADI-R was found to have good specificity but poor sensitivity at detecting childhood autism at 20 months; however, the stability of diagnosis from 20 to 42 months was good. In addition, the ADI-R at age 20 months was not sensitive to the detection of related PDDs or Aspergers syndrome. The continuity and discontinuity between behavioural abnormalities identified at both timepoints in the three domains of impairment in autism was examined, both in children who met final clinical criteria for an autistic spectrum disorder, and for children with language disorder who did not, as well as for a small sample of typically developing children.

The Frequency and Distribution of Spontaneous Attention Shifts between Social and Nonsocial Stimuli in Autistic, Typically Developing, and Nonautistic Developmentally Delayed Infants

Spontaneous shifts of attention were observed in autistic, typically developing, and nonautistic developmentally delayed infants. Three types of attention shifting behaviour were observed; (1) between an object and another object, (2) between an object and a person, and (3) between a person and another person. The two control groups shifted attention more frequently between an object and a person than between an object and another object or between a person and another person. The infants with autism showed a different pattern, shifting attention between an object and another object more than any other type of shift. Furthermore, infants with autism showed fewer shifts of attention between an object and a person, and between person and person, than did the two control groups. They also spent less time overall looking at people and looked more briefly at people and for longer durations at objects, compared to the two control groups. These results indicate an abnormality in social orientation in autism even at the early age of 20 months.

Early identification of autism by the CHecklist for Autism in Toddlers (CHAT).

Acknowledgements 2 We are grateful to the MRC for support for this work through 3 successive project grants to SBC, AC, and GB. Carol Brayne gave us valuable feedback on an earlier draft of this paper. 3 The CHecklist for Autism in Toddlers (CHAT) is a screening instrument which identifies children aged 18 months who are at risk for autism. This article explains how the CHAT was developed, how the CHAT should be used, and provides a brief introduction to autism.

An experimental investigation of social-cognitive abilities in infants with autism: Clinical implications

Competing theoretical accounts of psychopathological development in individuals with autism emphasize the role of different infant social, cognitive and affective factors, including affective responsivity, pretend play, joint attention, and imitation. However, due to the fact that autism is rarely diagnosed before the age of 3, until now these abilities have only been studied with school-age children, adolescents, or young adults with autism. Taking advantage of a new prospective screening instrument for autism in infancy (Baron-Cohen et al., 1996), the present study compared the performance of 20-month-old infants with autism and pervasive developmental disorder to that of children with developmental delay without autism on experimental tasks of empathic response, pretend and functional play, joint attention and requesting behaviors, and imitation. The 20-month-old infants with autism failed to use social gaze declaratively in the joint attention task, they showed poor emphatic response, fewer imitated modelled actions on objects, and none produced spontaneous pretend play. Surprisingly, the infants with pervasive developmental disorder did not perform significantly differently from the infants with developmental delay without autism on any of the measures. The identification of autism-specific impairments in early social cognitive abilities may have important clinical implications, for the early diagnosis of the disorder and for the setting of goals and monitoring of progress in early intervention programs.

Commentary: The modified checklist for autism in toddlers

The question of when it is best to screen for autism may only be answered by a series of empirical studies. These will be difficult to plan, fund, and conduct, and will by necessity take many years because of the need to systematically follow up the whole cohort screened. In our study, we identified 19 of the 50 children with autism by their profile at the 18-month screen (though note that some fell out of risk status at the repeat screen 1 month later--thus sacrificing sensitivity for improved positive predictive power). Through the subsequent surveillance methods we employed, we identified the remaining cases as follows: 5 at 42 months, 4 between 42 months and 7 years, and 25 at 7 years. We do not mean to end on a pessimistic note. Our experiences have been positive both in regard to the instrument we developed and the effects that using it have had on the health practitioners involved in the research study. In discussion, practitioners have commented on the usefulness of knowing what prelanguage and prosocial skills can reliably be looked at during the 18-month check. Training using the CHAT and eliciting its behaviors improved the skills and confidence of primary health practitioners. It is our view that this has had the effect of reducing the age at which autism is recognized and cases are referred on for a developmental assessment. The work reported by Robins er al. makes an important contribution to this ongoing research and clinical process as we attempt to accurately identify children with autism at a young age.

An investigation of first‐order false belief understanding of children with congenital profound visual impairment

This study assessed theory of mind understanding in children with congenital profound visual impairment (CPVI): children who have had no access to visual information throughout development. Participants were 18 children with CPVI and no other impairments, aged between 5 and 11 years, and 18 children with normal vision, matched individually on chronological age, verbal IQ and verbal mental age. Three first-order false belief tasks were presented twice each; the three tasks varied in the extent of deception and involvement of the child. Six of the children with CPVI failed one or more of the false belief tasks; all sighted children passed all of the tasks. The manipulations of deception and involvement did not influence the performance of the children with CPVI. Participant characteristics of the children with CPVI were examined in relation to their performance on the false belief tasks: chronological age and type of school attended were not found to be related to performance; verbal IQ and verbal mental age were found to differ in children with good and poor performance on the false belief tasks. The results are consistent with either a general pattern of delay in theory of mind development for children with CPVI, or with a subset of children who have longer-term difficulties in this area.