The long-term effects of prenatal nicotine exposure on verbal working memory: An fMRI study of young adults

Using functional magnetic resonance imaging (fMRI), the long-term effects of prenatal nicotine exposure on verbal working memory were investigated in young adults. Participants were members of the Ottawa Prenatal Prospective Study, a longitudinal study that collected a unique body of information on participants from infancy to young adulthood. This allowed for the measurement of an unprecedented number of potentially confounding drug exposure variables including: prenatal marijuana and alcohol exposure and current marijuana, nicotine and alcohol use.Twelve young adults with prenatal nicotine exposure and 13 non-exposed controls performed a 2-Back working memory task while fMRI blood oxygen level-dependent responses were examined. Despite similar task performance, participants with more prenatal nicotine exposure demonstrated significantly greater activity in several regions of the brain that typically subserve verbal working memory including the middle frontal gyrus, precentral gyrus, the inferior parietal lobe and the cingulate gyrus.These results suggest that prenatal nicotine exposure contributes to altered neural functioning during verbal working memory that continues into adulthood. Working memory is critical for a wide range of cognitive skills such as language comprehension, learning and reasoning.Thus, these findings highlight the need for continued educational programs and public awareness campaigns to reduce tobacco use among pregnant women.