This study investigated social attention impairments in autism (social orienting, joint attention, and attention to another's distress) and their relations to language ability. Three- to four-year-old children with autism spectrum disorder (ASD; n = 72), 3- to 4-year-old developmentally delayed children (n = 34), and 12- to 46-month-old typically developing children (n = 39), matched on mental age, were compared on measures of social orienting, joint attention, and attention to another's distress. Children with autism performed significantly worse than the comparison groups in all of these domains. Combined impairments in joint attention and social orienting were found to best distinguish young children with ASD from those without ASD. Structural equation modeling indicated that joint attention was the best predictor of concurrent language ability. Social orienting and attention to distress were indirectly related to language through their relations with joint attention. These results help to clarify the nature of social attention impairments in autism, offer clues to developmental mechanisms, and suggest targets for early intervention.

Coded home videotapes of 11 autistic and 11 normally developing children's first year birthday parties for social, affective, joint attention, and communicative behaviors and for specific autistic symptoms. Autistic children displayed significantly fewer social and joint attention behaviors and significantly more autistic symptoms. In combination, four behaviors correctly classified 10 of 11 autistic children and 10 of 11 normal children. These behaviors consisted of pointing, showing objects, looking at others, and orienting to name.

Previous work based on observations of home videotapes indicates that differences can be detected between infants with autism spectrum disorder and infants with typical development at 1 year of age. The present study addresses the question of whether autism can be distinguished from mental retardation by 1 year of age. Home videotapes of first birthday parties from 20 infants later diagnosed with autism spectrum disorder, 14 infants later diagnosed with mental retardation (without autism), and 20 typically developing infants were coded by blind raters with respect to the frequencies of specific social and communicative behaviors and repetitive motor actions. Results indicated that 1-year-olds with autism spectrum disorder can be distinguished from 1-year-olds with typical development and those with mental retardation. The infants with autism spectrum disorder looked at others and oriented to their names less frequently than infants with mental retardation. The infants with autism spectrum disorder and those with mental retardation used gestures and looked to objects held by others less frequently and engaged in repetitive motor actions more frequently than typically developing infants. These results indicate that autism can be distinguished from mental retardation and typical development by 1 year of age.

Children with autism were compared to developmentally matched children with Down syndrome or typical development in terms of their ability to visually orient to two social stimuli (name called, hands clapping) and two nonsocial stimuli (rattle, musical jack-in-the-box), and in terms of their ability to share attention (following another's gaze or point). It was found that, compared to children with Down syndrome or typical development, children with autism more frequently failed to orient to all stimuli, and that this failure was much more extreme for social stimuli. Children with autism who oriented to social stimuli took longer to do so compared to the other two groups of children. Children with autism also exhibited impairments in shared attention. Moreover, for both children with autism and Down syndrome, correlational analyses revealed a relation between shared attention performance and the ability to orient to social stimuli, but no relation between shared attention performance and the ability to orient to nonsocial stimuli. Results suggest that social orienting impairments may contribute to difficulties in shared attention found in autism.

Studies have shown that young children with autism are not impaired on prefrontal tasks relative to what would be expected for their mental age, raising questions about the executive dysfunction hypothesis of autism. These studies did not include ventromedial prefrontal tasks, however. The present study examined whether young children with autism spectrum disorder (ASD) are impaired on ventromedial prefrontal tasks, and whether performance on such tasks is correlated with a core autism symptom, joint attention ability. Seventy-two 3- to 4-year-old children with ASD, 34 3- to 4-year-old developmentally delayed children, and 39 12- to 46-month-old typically developing children, matched on mental age, were administered ventromedial and dorsolateral prefrontal tasks and joint attention tasks. Children with ASD performed similarly to comparison groups on all executive function tasks, indicating that at this early age, there is no autism-specific pattern of executive dysfunction. Ventromedial, but not dorsolateral, prefrontal task performance was strongly correlated with joint attention ability, however. The ventromedial prefrontal cortex is hypothesized to play a role in the development of joint attention and possibly some aspects of the autistic syndrome.

The aims of the present study were to describe variations in the early course of development in autism by utilizing an in-depth parent interview that incorporated techniques to improve accuracy of parent recall, and to examine the relation between variations in early developmental course in autism and behavioral outcome at 3-4 years of age. The Early Development Interview, which consisted of questions about child's behavior in several domains from birth through 2 years of age, was created and administered to parents of 72 3-4-year-old children with autism spectrum disorder and 34 3-4-year-old children with developmental delay, who were matched on mental and chronological age, and 39 1-4-year-old typically developing children, who were matched to the clinical groups on mental age. At 3-4 years of age, children were administered standardized measures (some clinician administered and some parent report); these included verbal and nonverbal IQ, autism symptom severity, and adaptive and aberrant behavior. Based on the Early Development Interview, children with autism spectrum disorder (ASD) were reported to have elevated symptoms in the social and regulatory domains by 3-6 months. By 12-15 months, parents of children with ASD reported significantly higher levels of social symptoms than parents of children with developmental delay. At 3-4 years of age, children with autism with early vs. late onset of symptoms, and with vs. without a history of loss of skills (regression) were not found to differ on standardized tests of verbal and nonverbal IQ and observational measures of autism symptom severity.

Both the medial temporal lobe and dorsolateral prefrontal cortex have been implicated in autism. In the present study, performance on two neuropsychological tasks--one tapping the medial temporal lobe and related limbic structures, and another tapping the dorsolateral prefrontal cortex--was examined in relation to performance on tasks assessing autistic symptoms in young children with autism, and developmentally matched groups of children with Down syndrome or typical development. Autistic symptoms included orienting to social stimuli, immediate and deferred motor imitation, shared attention, responses to emotional stimuli, and symbolic play. Compared with children with Down syndrome and typically developing children, children with autism performed significantly worse on both the medial temporal lobe and dorsolateral prefrontal tasks, and on tasks assessing symptoms domains. For children with autism, the severity of autistic symptoms was strongly and consistently correlated with performance on the medial temporal lobe task, but not the dorsolateral prefrontal task. The hypothesis that autism is related to dysfunction of the medial temporal lobe and related limbic structures, such as the orbital prefrontal cortex, is discussed.

This report describes a case study of the development of an infant with autism who was observed closely by professionals from birth and to whom a comprehensive psychological evaluation was administered at approximately 1 and 2 years of age. During the first 6 months of life, this infant displayed difficulties in oral motor coordination and muscle tone that fluctuated between hypotonia and hypertonia. He startled easily, had poor state regulation, and was hypersensitive to touch. Notably, however, during the first 6 months, this infant vocalized and responded socially to others by smiling and cooing. During the second half of the first year, he continued to demonstrate diffuse sensorimotor difficulties and diminished oral motor control. Hypersensitivity now extended to a wider range of stimuli. He had problems in sleep regulation. Motor stereotypies, including rocking, head banging, and toe walking, were observed. Difficulties in the domain of social interaction began to emerge during the second 6 months, including poor eye contact, failure to engage in imitative games, and lack of imitative vocal responses. By a little over 1 year of age, this infant met diagnostic criteria for autism based on the Autism Diagnostic Interview. There were several domains in which this toddler with autism did not show impairments. In the areas of immediate memory for actions, working memory, response inhibition, and speech perception, this 1-year old with autism displayed no evidence of significant impairment on the tests administered. This case study offers clues regarding the nature of autism at its earliest stages. Understanding early development in autism will be important for developing early screening and diagnostic tools.