Functional neural networks underlying response inhibition in adolescents and adults

Abstract

This study provides the first description of neural network dynamics associated with response inhibition in healthy adolescents and adults. Functional and effective connectivity analyses of whole brain hemodynamic activity elicited during performance of a Go/No-Go task were used to identify functionally integrated neural networks and characterize their causal interactions. Three response inhibition circuits formed a hierarchical, inter-dependent system wherein thalamic modulation of input to premotor cortex by fronto-striatal regions led to response suppression. Adolescents differed from adults in the degree of network engagement, regional fronto-striatal-thalamic connectivity, and network dynamics. We identify and characterize several age-related differences in the function of neural circuits that are associated with behavioral performance changes across adolescent development.

Figure 1

Brain regions in each component associated with successful response inhibition. 1A) fronto-striatal-thalamic indirect pathway engagement consistent with modulation of motor function (Blue); 1B) precentral gyri deactivation concurrent with prefrontal and inferotemporal activation (Yellow); 1C) frontoparietal circuit activity consistent with higher-order presentations of No-Go’ response contingencies (Red). Statistical results are thresholded at a low of p < .001, corrected for searching the whole brain.

Figure 2

Results of network modeling. 2A) Averages of each component ICA timecourse for successful No-Go trials; 2B) Dynamic causal model results showing significant connections among the regions and the effects of successful response inhibition on those pathways; 2C) Average of adolescent and adult ICA timecourses for the Red frontal-parietal neural network.