Imagination

Imagination, conscious mental process of evoking ideas or images of objects, events, relations, attributes, or processes.

Imagination, perception (the conscious integration of sensory impressions of external objects and events), and memory (the mental evocation of previous experiences) are essentially similar mental processes. This is particularly true when their content consists of sensory images. Psychologists occasionally distinguish between imagination that is passive or reproductive, by which mental images originally perceived by the senses are elicited, and imagination that is active, constructive, or creative, by which the mind produces images of events or objects that are either insecurely related or unrelated to past and present reality. At one time the term imagination included the reviving or “recollecting” processes (memory), as well as the process of creating mental images (imagination). The present stricter definition of imagination excludes and contrasts with that of memory, as the concept of forming something new contrasts with that of reviving something old.

When an imagined and a real perception are simultaneous, the imagined perception may be confused with or even mistaken for the true perception. One objectively measurable example of this phenomenon is synesthesia—an experience in which the stimulation of one sense elicits a perception that ordinarily would be elicited had another sense been stimulated, as when a loud noise registers as a blinding light, or vice versa.

Events and objects that apparently are perceived while dreaming are examples of imaginative exercises that are neither verifiable nor repeatable. In all these psychological events, imagination takes over the functions of perception. The most extreme examples of this kind of confusion are the hallucinations suffered by victims of severe mental disorders such as schizophrenia. When a genuine perception is assumed by the individual to be an imagined one, an opposite error is said to exist; this rare occurrence can be induced in the laboratory under experimental conditions, as in one well-known case in which subjects are asked to imagine a scene or object on a screen, upon which, unknown to them, the same scene or object has been dimly projected. The subject almost invariably believes that the projected image is the product of their own imagination even when it does not correspond exactly with the imagined perception.