The brain communicates with muscles and the sensory periphery through localized neuron nuclei. To illustrate this, when you move your right thumb, the impulses traveling out of your skull, through your spinal cord, and down your arm originate in motor cortex nuclei dedicated to right-thumb movement. Next to this right-thumb cortex lies the cortex controlling your right index finger; whatever else you move voluntarily is also location mapped: your foot, your calf, and so on. Not only motor signals but also sensory signals are location mapped, so that when you touch something with your thumb, that sensation registers in the thumb-dedicated sensory cortex, and the same is true for other sensory signals—they map to specific cortex regions.
Local populations of neurons collaborating in collective responses are found throughout the brain. Another example is our complex, multiflow, multistage visual stream, where some neural populations respond to colors, others to geometric shapes, and others to movement in a particular area of the visual field.