Prenatal marijuana exposure impacts executive functioning into young adulthood: An fMRI study

Understanding the potentially harmful long term consequences of prenatal marijuana exposure is important given the increase in number of pregnant women smoking marijuana to relieve morning sickness. Altered executive functioning is one area of research that has suggested negative consequences of prenatal marijuana exposure into adolescence. Investigating if these findings continue into young adulthood and exploring the neural basis of these effects was the purpose of this research. Thirty one young adults (ages 18–22 years) from the longitudinal Ottawa Prenatal Prospective Study (OPPS) underwent functional magnetic resonance imaging (fMRI) during four tasks; 1) Visuospatial 2-Back, 2) Go/NoGo, 3) Letter 2-Back and 4) Counting Stroop task. Sixteen participants were prenatally exposed to marijuana while 15 had no prenatal marijuana exposure. Task performance was similar for both groups but blood flow was significantly different between the groups. This paper presents the results for all 4 tasks, highlighting the consistently increased left posterior brain activity in the prenatally exposed group compared with the control group. These alterations in neurophysiological functioning of young adults prenatally exposed to marijuana emphasizes the importance of education for women in child bearing years, as well as for policy makers and physicians interested in the welfare of both the pregnant women and their offspring's future success

Neural impact of low-level alcohol use on response inhibition: An fMRI investigation in young adults

It is widely known that alcohol consumption adversely affects human health, particularly in the immature developing brains of adolescents and young adults, which may also have a long-lasting impact on executive functioning. The present study investigated the neural activity of 28 young adults from the Ottawa Prenatal Prospective Study (OPPS) using functional magnetic resonance imaging (fMRI). The purpose of this study was to discover the impact of regular low-level alcohol consumption on response inhibition as the participants performed a Go/No-Go task. Results indicated that, despite a lack of performance differences, young adults who use alcohol on a regular basis differ significantly from those who do not use alcohol regularly (if at all) with respect to their neural activity as the circuitry engaged in response inhibition is being challenged. Specifically, areas that showed significantly more activation in users compared to controls included the left hippocampus, parahippocampal gyrus, superior frontal gyrus, precentral gyrus, right superior parietal lobule, and the cerebellum. These results suggest that even in low amounts, regular consumption of alcohol may have a significant impact on neurophysiological functioning during response inhibition in the developing brain of youth

Working Overtime: Altered Functional Connectivity in Working Memory Following Regular Cannabis Use in Young Adults

There is an emerging consensus that regular cannabis use may be detrimental to the developing brain, including potential long-lasting changes in executive functioning. Consequently, the present study examined neural activation and performance on a working memory n-back task using functional magnetic resonance imaging (fMRI) in a sample of young adults (ages 19 to 21) from a longitudinal research sample. Regular cannabis users (n = 10) were compared with non-regular cannabis user controls (n = 14) while completing the letter n-back task during fMRI. While there were no differences across performance indices, imaging parameters showed significant differences in brain activation during task performance. Specifically, there wa