Zoha Ahmad¹, Ilana Tulbovich¹, Batsheva Hadad², Erez Freud¹; ¹York University, ²University of Haifa

A central prediction of the Two Visual Systems framework is that perception integrates multiple object features, whereas visually guided actions rely on analytic extraction of task-relevant dimensions. Our previous work showed that this functional dissociation is reduced in autism, with autistic grasping influenced by extrinsic contextual information such as spatial illusions and stimulus-history statistics. Here, we examined whether this reduced specialization extends to intrinsic object structure. Autistic (n=28) and non-autistic (n=28) adults perceptually estimated and grasped objects varying orthogonally in their width (relevant) and height (irrelevant). In the perceptual task, both groups showed a clear Height–Width illusion, demonstrating that the irrelevant height dimension biased size judgments. However, only autistic participants showed this interference in grasping, whereas non-autistic participants scaled their grip solely to width, preserving the expected analytic dissociation between perception and action. Full-trajectory analysis using Dynamic Time Warping (DTW) revealed two additional signatures of atypical visuomotor computation in autism: (1) non-autistic trajectories clustered by the relevant width dimension, whereas autistic trajectories clustered by object identity, indicating a holistic encoding of shape; and (2) autistic participants exhibited reduced within-condition consistency, reflecting diminished visuomotor efficiency. This pattern is consistent with broader evidence for reduced cortical specialization in autism, suggesting diminished functional differentiation between perceptual and visuomotor systems. Together, these findings extend prior contextual effects to intrinsic object structure and demonstrate that autistic visuomotor control is driven by holistic, perception-like representations rather than analytic, dimension-based processing.