DISSOCIATION AND HALLUCINATIONS

   The term dissociation comes from the Latin words dis (apart, away from each other) and asso-ciare (to gather, to unite). It was used as early as 1889 by the French philosopher and hypnotist Pierre Marie Félix Janet (1859-1947), and may have been introduced by him. The notion of dissociation is notorious for its wide-ranging meanings and connotations, but many definitions revolve around the notion ofan intrapsychic connection that is absent where it should be present, and the ensuing compartmentalization of mental functions. This compartmentalization involves a disconnection and subsequent isolation of mental functions -i.e. memory, personal identity, perception of the environment from the conscious I.In early accounts of dissociation, the ensuing isolation of mental functions used to be conceptualized as rather absolute. From the 1920s onwards, however, the notion of dissociation has also been allowed to apply to cases where a certain degree of interference or 'leakage' between the respective mental domains and the conscious I remains intact. It is generally held that the conceptual basis for the theory of dissociation stems from the work of the American physician Benjamin Rush (1745-1813), and from French pioneers such as Jacques-Joseph Moreau de Tours (18041884) and Jean Martin Charcot (1825-1893). In conformity with the work of the Swiss psychiatrist Carl Gustav Jung (1875-1961), dissociation tends to be explained in terms of a subconscious defense mechanism that either keeps conflicting strivings or impulses apart, or separates threatening ideas and feelings from conscious awareness. Conceptually as well as pathophysiologically, dissociation is associated primarily with states of altered consciousness such as * ecstasy, * trance, rapture, hypnotic states, * twilight states, and somnambulism. During such states, elaborate hallucinations may either occur spontaneously, or be induced by a third party (such as a hypnotist). The ensuing hallucinations are referred to as * dissociative hallucinations. A somewhat different use of the term dissociation can be found in the work of the German hallucinations researcher Edmund Parish (1861-1916). For an account of this usage, see the entry Dissociation model of hallucinatory experience.

   References

   Braude, S.E. (2004). Memory: The nature and significance of dissociation.In: The philosophy of psychiatry. A companion. Edited by Radden, J. Oxford: Oxford University Press.

   Janet, P. (1889). L'automatisme psychologique. Essai de psychologie expérimentale sur les formes inférieures de l'activité humaine. Paris: Félix Alcan.

   Van der Hart, O., Horst, R. (1989). The dissociation theory of Pierre Janet. Journal ofTrau-matic Stress, 2, 397-412.