Sensory-motor deficits in children with Fetal Alcohol Spectrum Disorders assessed using a robotic virtual reality platform
prenatal alcohol exposure , sensory-motor control , reaching , body position sense , virtual reality , robotics
Maternal consumption of alcohol during pregnancy can induce a range of behavioral and cognitive deficits in offspring, which are collectively termed Fetal Alcohol Spectrum Disorders (FASD). There are significant delays in motor development and sensory-motor skills in children with FASD, but the underlying neurobiological mechanisms of these deficits are poorly understood. The goal of this research project is to test the hypothesis that the Kinesiological Instrument for Normal and Altered Reaching Movements (KINARM) will serve as an effective tool for identifying and measuring specific, neurologically-based motor deficits in children with FASD. These deficits were revealed through investigation of multi-joint upper limb movements during the performance of sensory-motor tasks. Children (31 FASD; 83 controls, aged 5 to 18 years, male and female) performed: (1) a visually-guided reaching task with fingertip feedback only; and children (31 FASD; 49 controls, aged 5 to 18 years, male and female) performed: (2) an arm position-matching task in the absence of visual feedback. Children with FASD differed significantly from controls in many reaching task outcome measures, specifically those related to the initial motor response and corrective responses. In particular, large effect sizes were observed for outcome measures related to the first (initial) movement (corresponding to feedforward control; e.g., direction error; distance error), as well as for those measures related to corrective responses (corresponding to feedback control; e.g., difference between minimum and maximum hand speeds; number of speed peaks during movement). In the position-matching task, children with FASD constricted the spatial workspace of the subject-controlled arm relative to the robot-controlled arm, in the horizontal axis. There was also observed a systematic shift between the subject- and robot-controlled arms in the XY end position, resulting in significant error. Additionally, children with FASD exhibited significantly increased trial-to-trial variability for final hand position of the subject-controlled arm, over all targets, and for which large effect sizes were observed. The results suggest that children with FASD have difficulty integrating sensory information into planned motor movements. The KINARM is a promising research tool that may be used to assess motor control deficits in children affected by prenatal exposure to alcohol.