Acting toward or away from the body: the role of body-centered coding in praxis difficulties in children with Autism Spectrum Disorder.

Introduction: The body functions as the principal spatial and sensorimotor reference frame for extracting dynamic information from movement. Action can be organized relative to the body (toward the body) or decentered from it (away from the body), requiring different demands on body schema and action planning. Praxis difficulties in autism spectrum disorder (ASD) are well documented; however, it remains unclear whether these impairments vary with the degree to which actions are anchored to the body as a reference system. Method: Three gesture tasks were performed by children with ASD and control subjects: action comprehension, pantomime, and imitation. Each condition included items that were either away-directed (moving away from the body, such as a pencil or eraser) or body-directed (moving toward the body, such as a toothbrush or comb). Performance was evaluated based on accuracy across task type and gesture direction. Results: Children with ASD showed a selective vulnerability in the execution and imitation of actions. Within-group analyses indicated significantly greater impairment for away-directed than for body-directed gestures.  In contrast, nondirectional differences emerged in action comprehension. Thus, the differences in action representation processes for object-related actions toward and away from the body may be explained by a specific bodily role. Discussion: This pattern suggests that action-planning difficulties in ASD may reflect reduced use or stability of body-centered spatial coding rather than impaired action knowledge. Distinguishing gesture direction relative to the body may therefore provide a sensitive marker of praxis impairment in autism, supporting embodied accounts of social-motor difficulties.