The speed of nerve impulses
Nerve impulse speed varies enormously in different types of neuron. The fastest travel at about 250 mph – faster than a Formula 1 racing car.
Nerve impulse frequency
Each impulse is the same size – it is the frequency that carries information about the intensity of the signal. For example, as you turn up the dimmer switch on your bedroom light, the size of the nerve impulses from your eye stay the same but the rate at which they are generated increases.