Disentangling imitation and dyspraxia in individuals with autism (original) (raw)

Autism is a complex neurodevelopmental disorder characterised by a 'triad of impairments' in the areas of social interaction; language and communication; and restrictive, repetitive, and stereotypical patterns of behavior (American Psychiatric Society, DSM-IV, 1994). The DSM-IV diagnostic criteria for autism (1994) was the end result of an international collaboration of both research and clinical institutions across twenty-one different sites, and included the evaluation of almost 1,000 cases of autism (Volkmar, Klin, & Cohen, 1997). In this new classification, autistic disorder was included under the general category of PDD or Pervasive Developmental Disorders. Five categories are currently listed under the PDD umbrella: Autistic Disorder (AD); Asperger Syndrome (AS); Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS); Rett Syndrome; and Childhood Disintegrative Disorder. For accurate diagnosis of autism (DSM-IV 299.0), a total of at least six items from the three major groups are required; two of the criteria for social interaction (group 1), one from impaired communication (group 2) and one from restricted interests or repetitive behaviours (group 3). Also, "a delay or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play" (DSM-IV cited in Volkmar et al., 1997, p. 28) must be documented. The World Health Organisation's (WHO) 10 th Edition of the International Classification of Diseases (ICD-10) is the second major classification system of diagnosis. The ICD-10 and the DSM-IV diagnostic classification systems are closely related according to 'legal convention' (Volkmar et al., 1997). However, there are differences Society reports that autism is "touching the lives of 500,000 families throughout the UK" (National Autistic Society, 2004). According to recent estimates, one in 100 children is reportedly affected by the disability in the UK alone (Baird, Simonoff, Pickles, Chandler, Loucas, Meldrum, & Charman, 2006). In 2000, the average ASD prevalence rate was 6.7 per 1,000 children (at 6 different sites) and in 2002, 6.6 per 1,000 children (at 14 different sites). In 2004, the CDC (Centers for Disease Control) found that the prevalence rates were between 2 and 6 per 1,000 children. Therefore, using the higher rate, it was reported that up to 1 in 166 children are on the autism spectrum. In 2007, the Autism and Developmental Disabilities Monitoring Network (part of the CDC) reported that the figure had risen to 1 in 150 children (ADDM, 2007). More than 1.5 million Americans are considered to be on the autism spectrum (Center for Disease Control Prevention, 2007). 2.1.4 Gestural Impairments within DSM-IV Diagnosis Autism is a developmental disability that affects not only the individual, but the entire family, and its impact on the family unit cannot be underestimated (National Research Council, 2001). One of the greatest sources of communication difficulty families and caregivers face when dealing with preverbal autistic children is that they do not compensate for their language deficit through the use of functional gestures, failing to spontaneously use conventional gestures to make their needs known (Wetherby, Prizant, & Hutchinson, 1998; Woods & Wetherby, 2003). Since the time of Kanner, gestural impairments in autism have been reported. Kanner (1943) published this description of a child from his original research, "Her expression was blank, though not unintelligent, and there was no communicative gestures" (p. 240). Curcio (1978) reported that children with autism did not use any pointing or showing gestures and stated that this performance was striking