Describe two ways that the nervous system filters information that is being transmitted to the brain.
Information from sensory receptors is coded in two ways. Firstly, each receptor is highly specific and will only fire in response to certain values of stimuli. For example, a receptor dealing with sound may respond to a small range of frequencies and may only be sensitive to low-pitched sounds. When this receptor fires, then, the signal indicates only a low-pitched sound.
Sensory receptors can also change the number and frequency of action potentials performed. A low number of action potentials could indicate a lower volume whereas a higher number of action potentials indicate a higher volume.