Motor response selection in children with fetal alcohol spectrum disorders.

Previous work has reported timing delays in motor response selection in children with prenatal exposure to alcohol when the information load involved responding to two stimulus choices. The present study examined whether the delay in response selection extends to conditions in which the information load is increased to four and eight stimulus choices. Twenty children aged between 12 and 17 years with fetal alcohol spectrum disorders (FASD) were compared to 17 non-alcohol-exposed controls (NC) on a reaction time (RT) task involving 1, 2, 4 or 8 visual stimulus choices. The task demands required the participant to release a response key as fast as possible when the stimulus light electronically paired with the response key was activated. With the number of stimulus choices expressed on a logarithmic scale, there was a significant and linear increase in RT for the FASD children as predicted by information processing theory. Additionally, the increase in RT for the FASD group was comparable to that observed for the NC children at each level of stimulus choice examined. It was concluded that FASD adolescents require additional time to process increasing amount of information, but that the time required for motor response selection is not delayed relative to control group performance.