What condition involves a sense perception without external stimulation?

The term that describes a sense perception occurring without external stimulation is "hallucination." Hallucinations can affect any of the senses, including sight, sound, taste, touch, and smell. They often occur in various mental health conditions, neurological disorders, or can be a result of substance use.

In contrast, a delusion refers to a strongly held belief that is contradicted by reality or rational argument, and it does not involve sensory perception. An illusion, on the other hand, is a misinterpretation of a real external stimulus – meaning there is something present, but it is perceived incorrectly. Dysphoria refers to a state of unease or generalized dissatisfaction, which does not pertain to sensory perceptions at all. Thus, hallucinations are uniquely characterized by the presence of perceptions without the input of real external stimuli.