Neural mechanisms of inhibitory control continue to mature in adolescence

Inhibition is a fundamental executive function necessary for self-management of behaviour. The ability to withhold prepotent responses shows protracted development, extending through childhood and into adulthood. Using magnetoencephalography (MEG) with co-registered MRI, the spatiotemporal neural processes involved in inhibitory control were examined in 15 adolescents and 15 adults during a Go/No-go task. Two tasks were run that contained inverse ratios of Go to No-go trials for the experimental (2:1) and control conditions (1:2). Using vector beamforming, images of neural activation between No-go and Go trials were compared for both age-groups and revealed recruitment of the right inferior frontal gyrus in adults (BA 45; 200-250ms), but delayed recruitment of the left inferior frontal gyri in adolescents (BA 45; 250-300ms). Left anticipatory-related activity near the hand motor region (BA 6) was present in both adolescents and adults, but for a longer duration in adults. Adolescents additionally recruited the right middle and superior temporal gyri (BA21, BA22), while adults engaged the right temporal gyrus (BA41) but for a much briefer duration. These findings of delayed recruitment of canonical inhibitory control areas with supplementary and prolonged involvement of temporal areas in adolescents compared to adults indicate an immature inhibitory network even in adolescence.