Co-Regulation of Movement Speed and Accuracy by Children with Heavy Prenatal Alcohol Exposure

Abstract

The study investigated how children with heavy prenatal alcohol exposure regulate movement speed and accuracy during goal-directed movements. 16 children ages 7 to 17 years with confirmed histories of heavy in utero alcohol exposure, and 21 nonalcohol-exposed control children completed a series of reciprocal tapping movements between two spatial targets. 5 different targets sets were presented, representing a range of task difficulty between 2 and 6 bits of information. Estimates of percent error rate, movement time, slope, and linear fit of the resulting curve confirmed that for goal-directed, reciprocal tapping responses, performance of the group with prenatal alcohol exposure was described by a linear function, as predicted by Fitts' law, by sacrificing movement accuracy. The index of performance was the same for the two groups: it initially increased, then leveled off for more difficult movements.