Atypical lateralization in Autism Spectrum Disorder

Objective: Autism Spectrum Disorder (ASD) has been associated with atypical patterns of handedness. The current study sought to examine the lateralization of handedness and determine specific patterns of handedness in ASD.;Participants and Methods: Archival data was utilized to compare an ASD group (N=49) to the normative population (N=1,910) provided by the Wide Range Assessment of Visual Motor Abilities (WRAVMA) manual. The ASD group was administered the Pegboard Test of the WRAVMA. A Difference Score was calculated for each participant based on the relative difference in skill between hands. This score was used to determine degree of lateralization and was compared against the normative population.;Results: A z-test was computed to evaluate whether the relative difference in skill between hands in an ASD group was different from the normative population. The threshold for significance was set at p<.05. The ASD group demonstrated less variation in skill between hands when compared to the normative population. 53% of the ASD group demonstrated equal or near equal skill between hands suggesting a deficiency in lateralization for handedness.;Conclusions: The current data indicate that individuals with ASD and individuals with typical neurodevelopment demonstrate significantly different patterns of handedness. The ASD group demonstrated far less variation in skill between hands indicating reduced or unestablished lateralization for handedness. These data suggest that lateralization assessments may be beneficial as a diagnostic tool for the early detection of ASD.