A false sensory perception in the absence of a real external stimulus is

hallucination

Explanation:

A hallucination is a sensory perception experienced in the absence of an external stimulus, as distinct from an illusion, which is a misperception of an external stimulus. ... Psychological research has presented the idea that hallucinations may result from biases in what are known as metacognitive abilities

explanation:

eventually, the disease can cause permanent damage or deterioration of the nerves. some people with ms experience a gradual onset and steady risk factors.

princess bubblegum believes that the best cookies are always homemade.