text: Experimental data indicate that -LRB- I -RRB- single neurons in these regions are broadly tuned to parameters of movement ; -LRB- 2 -RRB- appropriate commands are elaborated by populations of neurons ; -LRB- 3 -RRB- the << coordinated action of neu-rons >> can be visualized using a [[ neuronal population vector -LRB- NPV -RRB- ]] .