Motor response programming and movement time in children with heavy prenatal alcohol exposure

The present experiment assessed motor response programming and movement time in children with histories of heavy prenatal alcohol exposure (PEA). Alcohol-exposed children between the ages of 7 and 17 years were classified into two groups: Fetal Alcohol Syndrome (FAS: n = 9) and children with PEA (PEA: n = 19) but who did not have the defining characteristics of FAS. The FAS and PEA children were compared with non–alcohol-exposed children (NC: n = 23) when completing two tasks: a simple reaction time task (RT alone condition) and a reaction plus movement task (RT + Move condition). The movement involved responding to an imperative stimulus signal and depressing three target buttons in a set sequence. Participants completed 24 trials each for the RT alone and RT + Move response conditions. Results indicated no significant differences in performance among FAS, PEA, and NC groups during the RT alone condition. However, during the RT + Move condition, the FAS group produced significantly longer and more variable RTs than the PEA and NC groups, which produced comparable RTs. The FAS group also produced significantly slower movement times when moving to all three targets, whereas movement time variability did not significantly differ as a function of group. The observed results indicate children with FAS experience deficits in response programming and movement time production.