Response inhibition among early adolescents prenatally exposed to tobacco: an fMRI study

Abstract

Children prenatally exposed to tobacco have been found to exhibit increased rates of behavior problems related to response inhibition deficits. The present study compared the brain function of tobacco-exposed (n=7) and unexposed (n=11) 12-year-olds during a Go/No-Go response inhibition task using an event-related functional MRI (fMRI) design. Prenatal alcohol exposure, neonatal medical problems, environmental risk, IQ, current environmental smoke exposure, and handedness were statistically controlled. Tobacco-exposed children showed greater activation in a relatively large and diverse set of regions, including left frontal, right occipital, and bilateral temporal and parietal regions. In contrast, unexposed but not exposed children showed activation in the cerebellum, which prior research has indicated is important for attention and motor preparation. The diversity of regions showing greater activation among tobacco-exposed children suggests that their brain function is characterized by an inefficient recruitment of regions required for response inhibition.

Figure 1

Results of fMRI whole brain group analysis overlayed onto anatomical images. Significant activation differences are shown for the No-Go minus Go contrast (i.e., response inhibition). The threshold is p < .001 with 10 or more contiguous voxels and a height threshold of T = 4.14. Images are in radiological coordinates.