Leap motion-based bimanual coordination analysis in schizophrenia and autism spectrum disorder

Impairments in bimanual coordination have been reported in schizophrenia and autism spectrum disorder (ASD), yet their characteristics and specificity remain unclear. This study employed a Leap Motion Controller (LMC) to assess fine motor coordination in 24 patients with schizophrenia, 19 individuals with ASD, and 20 healthy controls (HCs) using a bimanual peg pinch task. Coordination was quantified through spatial symmetry and temporal phase locking (PLV) of index and thumb movements. Individuals with schizophrenia showed significant impairments in both spatial and temporal coordination compared to HCs, consistent with prior literature and supporting the notion that such motor deficits may reflect neurodevelopmental anomalies. In contrast, no significant group-level differences were found between the ASD and HC groups, although the ASD group exhibited reduced variability in spatial metrics (e.g., box length), suggesting subtle but consistent coordination irregularities. These findings may be attributable to the characteristics of the ASD sample-relatively high-functioning adults diagnosed in adolescence or adulthood-whose motor profiles and developmental experiences may differ from those diagnosed in early childhood. Importantly, the study implies that PLV may not sufficiently capture spatial asymmetries observed in ASD, while spatial metrics such as size asymmetry may offer better sensitivity. Future research should employ spatially sensitive tools and stratified sampling to better characterize motor profiles in ASD and in psychiatric conditions involving neurodevelopmental disruption, such as schizophrenia. Combined with advanced analytic methods, LMC-based assessment may contribute to noninvasive early detection and differential diagnosis across such conditions.