- negative hallucination
- Also known as scotomization. Both terms are used to denote the failure to perceive an object or stimulus that is present in the extracorporeal world and lies within the subject's range of perception. The term negative hallucination is used in opposition to the term *positive hallucination, which denotes the perception of an object or stimulus that lacks an appropriate source in the extracorporeal world. The term negative hallucination was coined in or shortly before 1884 by the French internist Hippolyte Bernheim (18401919). Since then, it has been given various meanings and connotations. In Bernheim's case, the notion of negative hallucination was linked to hypnotism, a technique by means of which the subject can be made to believe that a certain object or stimulus within his or her range of perception is missing. The historical literature abounds with examples of individuals reacting to suggestions such as these with the inability to perceive a chair, a table, an orange, the hypnotist himself, or the hypnotist's head, even when these remain right in front of them. This phenomenon is also referred to as hypnotic blindness. It tends to be attributed to a combination of rapport and distraction of the subject's attention. However, according to the German hallucinations researcher Edmund Parish (1861-1916), negative hallucinations thus evoked should not be allowed to count as veritable negative hallucinations. Parish follows the German psychologist Wilhelm Wundt (1832-1920) in attributing such 'failures to perceive' to a state of lowered or narrowed consciousness, co-occurring with diminished attention (i.e. what is known today as *inattentional blindness). What Parish calls a *true negative hallucination is a sensory percept that can be made to disappear without diverting the subject's attention, but by suggesting, for example, that the glass upon which the subject concentrates will disappear after a clicking sound is heard. A third meaning of the term negative hallucination involves the failure to perceive an object or stimulus in the extracorporeal world because it is 'blocked' or 'covered' by a positive hallucination. A hallucinated house, for example, may obstruct a person's view of the actual landscape lying behind it. In the fourth place, the term negative hallucination is sometimes used as an equivalent of the term time-gap (i.e. a stretch of time of which one has no memory). Negative hallucinations of this type have been described in the literature on post-traumatic stress disorder. As noted by the Dutch psychologist Bernardine J. Ensink (b. 1951), "It is a matter of definition whether time-gaps are conceived as (negative) hallucinations. During time-gaps persons do not notice events present, whereas during hallucinations persons notice events not present." When negative visual hallucinations occur in the context of hysteria, they are historically referred to as * hysterical blindness. The notion of a negative hallucination does not necessarily apply to the visual modality. * Total anaesthesia, for example, can also be conceptualized as a negative hallucination. Negative hallucinations should not be confused with the * Perky phenomenon, in which images are perceived, but dismissed as imaginary in nature.ReferencesBernheim, H. (1888). De la suggestion et de ses applications à la thérapeutique. Deuxième édition. Paris: Octave Doin.Bourguignon, A., Manus, A. (1980). Hallucination négative, déni de la réalité et scotomisation. Annales Medico-psychologiques, 138, 129-153.Brakel, L.W. (1989). Negative hallucinations, other irretrievable experiences and two functions ofconsciousness. International Journal of Psycho-Analysis, 70(Pt 3), 461-479.Ensink, B.J. (1992). Confusing realities: A study on child sexual abuse and psychiatric symptoms. Amsterdam: VU University Press.Parish, E. (1897). Hallucinations and illusions. A study ofthe fallacies ofperception. London: Walter Scott.
Dictionary of Hallucinations. J.D. Blom. 2010.