Kinematic movement strategies in primary school children with 22q11.2 Deletion Syndrome compared to age- and IQ-matched controls during visuo-manual tracking

The present study focused on the mechanism subserving the production of kinematic patterns in 21 children with 22q11.2DS (mean age = 9.6 ± 1.9; mean FSIQ = 73.05 ± 10.2) and 21 age- and IQ-matched control children (mean age = 9.6 ± 1.9; mean FSIQ = 73.38 ± 12.0) when performing a visuo-manual tracking task in which they had to track a cursor rhythmically between 2 target zones. Children with 22q11.2DS moved faster (overall) and reached their maximum velocity sooner when compared to controls. However, the number of corrective submovements to attain the target did not differ. Children with 22q11.2DS seem to adopt a young ballistic movement strategy, with a fast ballistic first movement phase, followed by a second movement phase with very little online corrections to attain the target. Children with 22q11.2DS are not able to process the incoming feedback during the second movement phase to maximize the accuracy of the ongoing movement and use this phase to prepare the following. The fact that the parietal cortex and cerebellum are involved in action prediction and internal representation and are implicated in children with 22q11.2DS provides a possible neurological basis for their problems with prospective control and tracking behavior.