Differentiating prospective control information for catching in at-risk and control adolescents.

This paper investigated the use of prospective control in catching and how the results can be used as a sensitive tool to detect diffuse signs of brain dysfunction. A detailed analysis of 286 catching movements of eight adolescents (two males, six females [four very-low-birth weight {VLBW}, one small for gestational age {SGA}, and three appropriate for gestational age]; mean age 14 y 5 mo [SD 6 mo]; range 14-15 y) was performed blind for this purpose. The moving target approached the participants from the side at three different, non-constant accelerations. The results showed that three adolescents used less advanced timing strategies that involved the lower-order variables of distance or velocity to govern movement initiation of at least one of their hands. Two of these were preterm VLBW and one was term SGA. The remaining adolescents, on the other hand, all relied on the higher-order variable of time-to-contact to initiate their hand movements, and were, therefore, considered low-risk. These results were compared with the cerebral magnetic resonance imaging results of the adolescents. The findings show that timing strategy pinpoints successfully those adolescents at risk of neurological problems. It was, therefore, concluded that the skill of using prospective information for catching can be used as a tool to detect diffuse signs of motor dysfunction, which are not readily detected by standard behavioural tests alone.