Final answer:
Spiral ganglion cells use both graded potentials and action potentials to process auditory information. Graded potentials in these cells can trigger action potentials, which then transmit sound information to the brain. Therefore, the correct answer is c) Both.
Step-by-step explanation:
The type of change in polarity in spiral ganglion cells relates to how these cells process auditory information. Spiral ganglion neurons are responsible for transmitting sound information from the cochlea to the brain. They convert graded potentials into action potentials. Graded potentials are local changes in the membrane potential that vary in size with the strength of the stimulus; they occur in sensory neurons and are referred to as generator or receptor potentials depending on their location and function.
When a sufficient graded potential reaches the initial segment of the axon, this triggers an action potential, which is an all-or-none electrical impulse that travels down the axon.
In the case of spiral ganglion cells, the receptor potential generated by hair cells in the cochlea can lead to the formation of an action potential within these neurons.
Thus, spiral ganglions utilize both graded and action potentials in the process of hearing. Given this information, the correct option is c) Both.