A DEVELOPMENTAL FUNCTIONAL MRI STUDY OF PREFRONTAL ACTIVATION DURING PERFORMANCE OF A GO-NO-GO TASK

This study examines important developmental differences in patterns of activation in the prefrontal cortex during performance of a Go-No-Go paradigm using functional magnetic resonance imaging (fMRI). Eighteen subjects (9 children and 9 adults) were scanned using gradient echo, e cho planar imaging during performance of a response inhibition task. T he results suggest four general findings. First, the location of activ ation in the prefrontal cortex was not different between children and adults, which is similar to our earlier pediatric fMRI results of pref rontal activation during a working memory task (Casey et al., 1995). S econd, the volume of activation was significantly greater for children relative to adults. These differences in volume of activation were ob served predominantly in the dorsal and lateral prefrontal cortices. Th ird, although inhibitory processes have typically been associated with more ventral or orbital frontal regions, the current study revealed a ctivation that was distributed across both dorsolateral and orbitofron tal cortices. Finally, consistent with animal and human lesion studies , activity in orbital frontal and anterior cingulate cortices correlat ed with behavioral performance (i.e., number of false alarms). These r esults further demonstrate the utility of this methodology in studying pediatric populations.