Haptic perception is altered in children with developmental coordination disorder

Developmental coordination disorder (DCD) is a neurodevelopmental disorder affecting the motor system, but it may also present with signs of somatosensory dysfunction. This study examined whether haptic perception, which relies on somatosensory afferents, is impaired in children with DCD. Haptic sensitivity and acuity were systematically quantified in children with DCD and contrasted to the performance of typically developing (TD) children and young adults (each group N = 20). All participants performed a curvature detection task measuring haptic sensitivity and a curvature discrimination task measuring haptic acuity. In both tasks, participants moved the index finger of their dominant hand over a surface contour and verbally indicated whether they could detect its curvature or discriminate between two curved contours. Based on their verbal responses haptic detection and discrimination thresholds were obtained. The main findings are as follows: First, the DCD group had significantly elevated haptic discrimination thresholds (lower haptic acuity) compared to both TD children and adult controls. Second, we found no evidence that haptic sensitivity is impaired in DCD. Third, haptic acuity significantly correlated with clinical motor measures, indicating that higher levels of haptic acuity were associated with higher motor abilities. We conclude that DCD may be associated with impaired haptic perception, which likely contributes to the observable fine motor deficits.