The frequency of nerve impulses increases as stimulus intensity increases.

The frequency of nerve impulses increases as stimulus intensity increases.

• A. True
• B. False
• C. Not determinable
• D. Depends on neuron type

Answer: (A)

Frequency coding describes how sensory stimulus intensity is represented by the rate at which a neuron fires. When a stimulus strengthens, the neuron's membrane is driven more strongly, so it reaches threshold more quickly after each refractory period and the time between spikes shortens. As a result the firing rate, i.e., the frequency of action potentials, increases with stimulus intensity. This continues up to the neuron's maximum firing rate set by the refractory periods. In a whole nerve, stronger stimuli can also recruit additional neurons to fire, but the frequency of impulses from the active neurons does rise with intensity, making the statement true.

Frequency coding describes how sensory stimulus intensity is represented by the rate at which a neuron fires. When a stimulus strengthens, the neuron's membrane is driven more strongly, so it reaches threshold more quickly after each refractory period and the time between spikes shortens. As a result the firing rate, i.e., the frequency of action potentials, increases with stimulus intensity. This continues up to the neuron's maximum firing rate set by the refractory periods. In a whole nerve, stronger stimuli can also recruit additional neurons to fire, but the frequency of impulses from the active neurons does rise with intensity, making the statement true.