Fig. 7: Executive control circuitry.
From: Functional architecture of executive control and associated event-related potentials in macaques
Conflict (orange), Event Timing (dark blue), and Goal Maintenance (dark red) neurons are illustrated with selected anatomical connections and laminar densities of calretinin (CR), calbindin (CB), and parvalbumin (PV) neurons21 and of D1 and D2 receptors72 (right). Dopamine projections from SNpc and VTA modulate all computations in SEF. Left, Conflict signal can arise through coincident inputs of gaze-holding (STOP, dark red) and gaze-shifting neurons (GO, green) directly from FEF and indirectly via thalamus from SC terminating in L2 and L3. Conflict signals integrated across apical and basal dendrites can be sent to multiple cortical and subcortical structures. Right, Schematic profiles of Event Timing and Goal Maintenance activity with numbered phases. Event Timing neurons can receive inputs from DLPFC and ACC informing them about an upcoming event. Ramping results from recurrent connections (1, dark blue). SEF can receive information about the stop-signal appearance and successful stopping from VLPFC and DLPFC and from Conflict neurons. This signal can suppress the ramping activity via inhibitory connections onto Event Timing neurons (2, dark blue), resetting these neurons for the next ramping phase (3, dark blue), which is terminated by the appearance of the feedback tone (4). Event Timing neurons can project to the caudate nucleus (CN) to inform the fronto-striatal reinforcement learning loop about experienced event timing. Goal Maintenance neurons can delay unwanted movement through the push-pull basal ganglia circuitry. Pyramidal neurons can project to the indirect (D2) pathway and inhibitory neurons can project to other pyramidal neurons, unobserved in this study (gray), that project to the direct (D1) pathway. Inputs from DLPFC and ACC terminating in L2/3 can inform SEF of the anticipated timing of task events for successful completion of the task based on the experienced SSD. These inputs can produce the phasic response in Goal Maintenance neurons (1, red) followed by persisting activity via recurrent connections with balanced excitation and inhibition (2, red). The feedback tone, integrated with the task rule from DLPFC, terminates operant control on behavior through CR and CB inhibition of the sustained activity (3). Further details in the text.
