Plots of the extracellular potential recorded at an electrode a distance R from the axon located at z = -59 mm as the impulse travels from z = -100 mm to z = 100 mm. The geometry is that of the spherical conductor placed as in Figure 4. When the electrodes are located close to the axon (R = 10 mm), the peak in the potential occurs as the nerve impulse passes near the electrodes. For electrodes far from the axon (R = 110 mm or R = 1014 mm) the peak extracellular potential is recorded as the impulse travels nearest the sphere (z = 0). The values of the potential are arbitrary and are for purposes of comparison of the different graphs within this figure only.