A simple network of three clusters of neurons in the plainfin midshipman's hindbrain and spinal cord generate the signals that control the muscle contractions for humming. This is an example of

A) a stimulus filter.
B) signal patterning.
C) a central pattern generator.
D) cortical magnification.

A central pattern generator (CPG) is a neural network that can produce rhythmic patterned outputs without sensory feedback. In the case of the plainfin midshipman's humming, the CPG in the hindbrain and spinal cord generates the signals for muscle contractions, allowing the fish to produce its humming sound without direct external stimuli guiding the process. This is a classic function of a CPG, which is to produce rhythmic or patterned motor activity, such as walking, swimming, or, in this case, humming.