There’s a whole-body action planning interrupted homunculus inside you

“it turns out that medical textbooks may be wrong about how all this happens. The books show a model of the brain in which the motor cortex is solely controlling movement. But scientists at Washington University School of Medicine in St. Louis have found that previously overlooked areas of the brain’s motor cortex appear to link control of specific muscles with information about the entire body and brain. As a result, the act of, say, reaching for a cup of coffee can directly influence blood pressure and heart rate. And the movement is seamlessly integrated into brain systems involved in planning, goals and emotion.”—”An overlooked brain system helps you grab a coffee — and plan your next cup.”

See: “Motor cortex (M1) has been thought to form a continuous somatotopic homunculus extending down the precentral gyrus from foot to face representations1,2, despite evidence for concentric functional zones3 and maps of complex actions4. Here, using precision functional magnetic resonance imaging (fMRI) methods, we find that the classic homunculus is interrupted by regions with distinct connectivity, structure and function, alternating with effector-specific (foot, hand and mouth) areas. These inter-effector regions exhibit decreased cortical thickness and strong functional connectivity to each other, as well as to the cingulo-opercular network (CON), critical for action5 and physiological control6, arousal7, errors8 and pain9. This interdigitation of action control-linked and motor effector regions was verified in the three largest fMRI datasets. Macaque and pediatric (newborn, infant and child) precision fMRI suggested cross-species homologues and developmental precursors of the inter-effector system. A battery of motor and action fMRI tasks documented concentric effector somatotopies, separated by the CON-linked inter-effector regions. The inter-effectors lacked movement specificity and co-activated during action planning (coordination of hands and feet) and axial body movement (such as of the abdomen or eyebrows). These results, together with previous studies demonstrating stimulation-evoked complex actions4 and connectivity to internal organs10 such as the adrenal medulla, suggest that M1 is punctuated by a system for whole-body action planning, the somato-cognitive action network (SCAN). In M1, two parallel systems intertwine, forming an integrate–isolate pattern: effector-specific regions (foot, hand and mouth) for isolating fine motor control and the SCAN for integrating goals, physiology and body movement.”—”A somato-cognitive action network alternates with effector regions in motor cortex.”

Hermetic Library Omnium There's a Whole Body Action Planning Interrupted Homunculus Inside You 23apr2023