Co-activation based parcellation of right dorsolateral prefrontal cortex

Introduction The dorsolateral prefrontal cortex (DLPFC) has consistently been implicated in the cognitive control of motor behavior but there is considerable variability in the exact location and extension of these activations across experiments. This poses the question of whether this variability reflects sampling error and spatial uncertainty in fMRI experiments or structural and functional heterogeneity of this region.Methods We defined a seed region by merging the DLPFC activation sites from four previous studies on motor control. We used co-activation-based parcellation to test for functional subdivisions in the DLPFC based on differential co-activation patterns across neuroimaging experiments. The functional connectivity differences that underly the clustering were assessed by contrasting MACM maps for the respective clusters and cross-validated by task-free connectivity analysis in 100 subjects.Results Co-activation based parcellation revealed a separation into an anterior-ventral and a posterior-dorsal cluster. Investigation of task-dependent and -independent connectivity revealed different connectivity patterns between the respective clusters. When cross-validating both analyses, converging evidence was found for stronger functional connectivity of the posterior DLPFC subregion with the intraparietal sulci, whereas the anterior subregion showed increased functional connectivity with the anterior cingulate cortex.Conclusion We propose the posterior portion of the DLPFC to be involved in motor control processes dependent on the interaction with stimulus processing and the anterior subregion to be involved in higher control processes of motor behavior such as performance and error monitoring. In summary, our connectivity analyses provide evidence that cognitive motor control engages two functionally distinct DLPFC subregions, which jointly might subserve the bridging of perception and action under conditions of increased cognitive demands.