Implicit and explicit memory functioning in children with heavy prenatal alcohol exposure.

Prenatal alcohol exposure is associated with widespread and devastating neurodevelopmental deficits. Numerous reports have suggested memory deficits in both humans and animals exposed prenatally to alcohol. However, the nature of these memory deficits remains to be characterized. Recently children with fetal alcohol syndrome were shown to have learning and memory deficits on a verbal learning and memory measure that involved free recall and recognition memory. The current study seeks to further characterize memory functioning in children with heavy prenatal alcohol exposure by evaluating priming performance. The choice of task is also relevant given previous studies of memory performance in patient groups with and without involvement of the basal ganglia, a group of structures known to be affected in fetal alcohol syndrome. Three groups were evaluated for lexical priming, free recall, recognition memory, and verbal fluency: (1) children with heavy prenatal alcohol exposure; (2) children with Down syndrome; and (3) nonexposed controls. The children with Down syndrome showed significantly less priming than alcohol-exposed children, who did not differ from controls. In addition, the alcohol-exposed children were impaired on the free recall task but not on the recognition memory task, whereas the children with Down syndrome performed significantly worse than the alcohol-exposed group on both tasks. Finally, on the verbal fluency task, children with heavy prenatal alcohol exposure were impaired on both category and letter fluency, but the degree of impairment was greater for letter fluency. These results further characterize the memory deficits in children with heavy prenatal alcohol exposure suggesting that in spite of learning and memory deficits, they are able to benefit from priming of verbal information.