Assessing Visuomotor Deficits in Children with SPD

Background: Visuomotor control is the process by which individuals integrate visual perception and motor coordination systems. Visuomotor control is thought to have important implications for academic and social development. Mounting evidence suggests that abnormal visuomotor processes are common to various neurodevelopmental disorders. Specifically, children with sensory processing dysfunction (SPD) are anecdotally reported to have challenges with dysgraphia which is predicated on visuomotor integration. Previously, scant attention has been devoted to directly assessing visuomotor deficits in this population.

Objectives: In this study, we aim to determine whether children with SPD show deficits in visuomotor integration using two direct assessment measures, one a standard clinical test and the other an experimental assessment. Further we are interested in investigating correlations between visuomotor outcomes and measures of white matter integrity in the SPD group to better understand the biologic underpinnings of this disorder.

Methods: In this project, we collected visuomotor assessments and DTI imaging in 42 children with SPD (mean age 10 +/- 1.5) and 34 typically developing controls (TDC; mean age 10.2 +/- 1.3). The visuomotor battery included the Beery-Buktenica Developmental Test of Visual-Motor Integration, (Beery^™ VMI; copying, matching and tracing subtests) and the Project: EVO^TM (EVO^TM) navigation assessment. The EVO^TM tool is a scientifically derived iPad videogame-like assessment with embedded adaptive algorithms. The EVO^TMnavigation assessment requires the player to steer their character through a dynamically moving environment with the goal of avoiding the walls and obstacles. Further, we assessed for correlations between our visuomotor measures and mean fractional anisotropy (FA) in selected regions of interest (ROI).

Results: Outcomes from our independent t-test group analysis revealed no significant group differences in any of the Beery VMI subtests, however the SPD group did preform significantly worse compared to the TDC group in the EVO^TM navigation assessment. Results from our neuroimaging brain-behavior correlational analysis showed that the copy, matching and tracing subtests of the Beery VMI and the EVO^TMnavigation assessment showed some overlapping and some unique tracts which appear to mediate these visuomotor abilities. The tracing subtest of the Beery VMI showed the most significant correlations.

Conclusions: These finds suggest that EVO^TM navigation assessment may be more sensitive than the Beery VMI for assessing visuomotor integration deficits in children with neurodevelopmental disabilities, including SPD. This could be due to the adaptive and game-like features of the EVO^TM navigation assessment, which minimize boredom and increase engagement. The ROIs that correlated with visuomotor deficits are areas thought to be involved in connecting lower-cortical regions to the motor cortex and frontal lobes. This might suggest faulty connectivity between these regions in children with SPD. These findings provide new insight into the biological implications for visuomotor deficits observed in children with SPD.