A LONGITUDINAL-STUDY OF EXECUTIVE FUNCTION AND THEORY OF MIND DEVELOPMENT IN AUTISM

Both executive function and theory of mind impairment have been suggested as primary deficits of autism. One test of the primacy of a deficit is its persistence and stability throughout development. This longitudinal study examined development of executive function and theory of mind abilities over a 3-year time period, comparing nonretarded autistic adolescents with learning-disabled controls matched on age, IQ, gender, and socioeconomic status (SES). Results indicate that both executive function and theory of mind abilities are seriously deficient in autistic individuals, improve little with development, may never reach normal functioning levels, and appear to eventually hit a developmental ceiling. Developmental variables showed little relationship to overall task performance or improvement in either cognitive domain. The similar developmental trajectories of executive function and theory of mind performance found in this investigation suggest that these skills may be related and interdependent, rather than independent modules of cognitive function. Implications for the neurological basis of autism and intervention are also discussed.