Fig. 7.

Proposed circuit mechanism for smooth recruitment of sequential items for working memory tasks. The entire cortex projects to the basal ganglia and the cerebellum; the output of these large structures projects preferentially to thalamic nuclei (VL, VA, and MD), which are connected with the frontal cortex, including motor/premotor and prefrontal areas. The basal ganglia are associated with habit formation, and the cerebellum with smooth sequencing of information. The preferential output of these structures to thalamic nuclei that project to prefrontal cortex may facilitate quick sampling of signals from the cortex for working memory tasks. GPe, globus pallidus external part; GPi, globus pallidus internal part; MD, mediodorsal thalamic nucleus; SNr, substantia nigra pars reticulata; STN, subthalamic nucleus; VA, ventral anterior thalamic nucleus; VL, ventral lateral thalamic nucleus.