Reduced Hand Specialization and Idiosyncratic Visuomotor Strategies in Autism During Naturalistic Object Manipulation.

Researchers studied how autistic and non-autistic adults use their hands during LEGO building tasks. Autistic participants used their right hand less often and were less likely to reach across their body. They preferred using blocks closer to them and moved more slowly with less consistent patterns. These differences might help identify autism earlier through objective movement assessments.

This study examined hand use patterns in autistic and non-autistic right-handed adults during naturalistic LEGO building tasks. Autistic participants showed reduced right-hand dominance, with fewer right-hand grasps and less crossing of the body midline with their dominant hand. They also demonstrated different spatial preferences, favoring blocks placed closer to their hands, and exhibited slower, more variable movement patterns compared to non-autistic participants. These findings suggest reduced cerebral specialization and altered visuomotor control strategies in autism, potentially offering objective markers for early identification.

Findings suggest potential for developing objective, movement-based assessment tools for autism identification. The reduced hand specialization and altered visuomotor strategies may inform occupational therapy interventions targeting motor skills and spatial coordination in autistic individuals.

Sample size not reported. Study limited to right-handed adults, which may not generalize to left-handed individuals or children. Single task paradigm (LEGO building) may not capture full range of visuomotor behaviors. Cross-sectional design limits understanding of developmental patterns.

Autistic individuals exhibit altered perceptual and visuomotor behaviors, potentially due to reduced cortical specialization. The current study focuses on handedness, a robust marker of cerebral specialization, which is less right-biased in autism. Previous studies have typically assessed handedness via questionnaires or simple manual tasks that do not characterize the dynamic, on-going nature of real-life actions. To address this gap, autistic and non-autistic right-handed adults recreated LEGO models from blocks placed on a standardized tabletop, enabling analysis of dynamic, real-world visuomotor behaviors.

Autistic participants displayed a lower proportion of right-hand grasps and fewer contralateral movements (i.e., crossing the body midline) with their right hand. Additionally, we observed differences in 3D space utilization, such that autistic participants exhibited a stronger preference for blocks placed closer to their hands. Finally, autistic participants were slower, and their movement trajectories were more idiosyncratic when compared with non-autistic participants. These results reveal reduced hand specialization and profound visuomotor control differences in autism, highlighting potential clinical utility for early, objective autism markers.