CENTRIFUGAL THEORY OF HALLUCINATORY ACTIVITY

   The centrifugal theory is an explanatory model of hallucinatory activity which is traditionally attributed to the German physiologist and zoologist Johannes Peter Müller (1801-1858). The centrifugal theory suggests that subcortical and/or cortical areas of the brain (or the mind, in a dualist reading) are responsible for mediating the initial impulse for some types of hallucinatory activity, which is then 'projected outwards' to produce the false impression of a sensory percept. Historical examples ofthe ensuing type of hallucination are known under the names * intuitive hallucination, * psychic hallucination, and *sensorial hallucination. In some versions of the centrifugal theory, the efferent impulse is considered to be conducted backwards, i.e. in an afferent direction, by the primary sensory pathways. The Italian psychiatrist Eugenio Tanzi (1856-1934), for example, hypothesizes that the primary sensory pathways possess such a capacity for 'reversed conductibility'. The centrifugal theory constitutes the conceptual counterpart of the * centripetal theory of hallucinatory activity.

   References

   Müller, J. (1826). Ueber die phantastischen Gesichtserscheinungen. Koblenz: Hölscher.

   Parish, E. (1897). Hallucinations and illusions. A study ofthe fallacies ofperception. London: Walter Scott.

   Tanzi, E. (1909). A text-book ofmental diseases. Translated by Ford Robertson, W., Mackenzie, T.C. London: Rebman Limited.