Decreased sensitivity to an unchanging stimulus is known as

Explanation:

Sensory adaptation refers to the adjustment of the sensory capacity of a person following prolonged exposure to stimuli.

To better understand this, it is necessary to explain that environmental stimuli cause a change in the sensitivity of a person's sensory receptors. Then, depending on the type of environmental stimulus, the determined receptor will be stimulated (related to the five main senses of the human being: sight, smell, taste, touch and hearing).

However, when a person gets used to a stimulus, adaptation occurs. Therefore, it will not respond to the stimulus in the same way as it did before.

A very common example is the relation with the smells (olfactory sense), because people get used quickly to the smells that surround them and then they stop "perceiving" the smell.

found in the nucleus

has mass of one amu