pseudohallucination

   A term that serves as a generic name for a group of loosely defined percepts that are reminiscent of * hallucinations proper, but fall short of one or more formal characteristics to deserve the predicate hallucination. During the era of classic psychiatry, pseudohallucinations were also referred to as Einbildungstäuschungen (i.e. 'sensory miscalculations'), *mental hallucinations, and * apperceptive hallucinations. Today the terms * quasi-hallucination, * dissociative hallucination, and * psychotic-like hallucination are sometimes used as synonyms. The term pseudohallucination was introduced in or shortly before 1868 by the German psychiatrist Friedrich Wilhelm Hagen (1814-1888), who employed it to denote a perceptual phenomenon that could be mistaken for a hallucination. The term gained a more specific connotation after its reintroduction in 1885 by the Russian psychiatrist Victor Kandinsky (1849-1889), who had experienced * visual hallucinations himself. Elaborating upon his experience as a doctor and a patient, he used the term to designate phenomena lying within the border region between the imagination and hallucinations proper. Kandinsky defined the pseudohallucination in physiological terms as "a subjective stimulation of certain sensory cerebral areas, which evokes concrete, and very lively perceptual conceptions or perceptual images that distinguish themselves sharply from hallucinatory images to our perceiving consciousness through the lack of objectivity or realness that characterize these latter phenomena, which turns them instead into something subjective, but also something abnormal, new, something distinct from ordinary perceptual images and imaginations." The German psychiatrist and philosopher Karl Jaspers (1883-1969), who adhered to Kandinsky's view, emphasized their appearance in so-called inner subjective space as well as their independence of the affected individual's conscious efforts. The Swiss psychiatrist Eugen Bleuler (1857-1939) and his son Manfred Bleuler (1903-1994) gave the term a slightly different meaning when they defined pseudohallucinations as "perceptions with full sensory clarity and a normal localization, but of which the false nature is recognized." The Italian psychiatrist Euge-nio Tanzi (1856-1934) wielded a definition that was closer to Jaspers', but he gave it a special twist by including a clause on their alleged locus of origin which he had borrowed from his former student Ernesto Lugaro (1870-1940). As Tanzi suggested, "Pseudo-hallucinations are mental images which, instead of being evoked by external objects or by internal processes of association, arise as phantasms by the action of a local abnormal stimulus upon the representational centres." Today pseudohallucinations are often described as hallucinations brought about by the exercise of the imagination and accompanied by the realization that the experience is not real. But the defining criteria still tend to vary somewhat from author to author, making it difficult to obtain a proper delineation of the phenomenon. Moreover, it is unclear whether hallucinating individuals are capable of discriminating these alleged phenomena from hallucinations proper. In a study performed by the Dutch hallucinations researchers Marius Romme (b. 1934) and Sandra Escher (b. 1945), this turned out to be an impossible task. Various other studies also failed to establish the validity and reliability of this distinction. As far back as 1894, the German hallucinations researcher Edmund Parish (18611916) expressed quite a refreshing opinion on the issue of pseudohallucinations when he said that, "Whether I see distinct and vivid images, or dim floating shapes, is a matter of no importance. The dimmest, most formless mist which I 'see,' or 'think I see,' is really seen, and even though this visual impression may have arisen subjectively, it should nevertheless be called a fallacious perception, hallucination, or illusion, quite irrespectively of how it originated, or what circumstances favoured the appearance of the phenomenon, and quite irrespectively also of its influence upon the percipient, or his attitude with regard to it." Nevertheless, the term pseudohallucination continues to be used in opposition to terms such as * hallucination proper, *true hallucination, and *veridical hallucination. An alternative for the term pseudohallucination would be the term * incomplete hallucination, which has been used since the late 19th century to denote a hallucination that lacks one or more ofthe formal characteristics of hallucinations proper.

   References

   Hagen, F.W. (1868). Zur Theorie der Hallucination. Allgemeine Zeitschrift für Psychiatrie, XXV, 1-113.

   Hare, E. (1973). A short note on pseudohallucinations. British Journal of Psychiatry, 122, 469-476.

   Kandinsky, V. (1885). Kritische und klinische Betrachtungen im Gebiete der Sinnestäuschungen. Erste und zweite Studie. Berlin: Verlag von Friedländer und Sohn.

   Kräupl-Taylor, F. (1981). On pseudo-hallucinations. Psychological Medicine, 11, 265279.

   Parish, E. (1897). Hallucinations and illusions. A study ofthe fallacies ofperception. London: Walter Scott. Romme, M.A.J., Escher, A.D.M.A.C. (1994). Accepting voices. London: MIND Publications.