Increased susceptibility to auditory conditioning in hallucinating schizophrenic patients: a preliminary investigation.

Auditory hallucinations have been elicited in the laboratory after repeated pairings of a tone (unconditioned stimulus) with a light (conditioned stimulus), until the presentation of the light alone resulted in subjects hearing the tone. This auditory sensory-conditioning phenomenon was first reported in normal subjects over a half-century ago. But the model remains, to date, untested in actively hallucinating patients. If sensory-conditioning mechanisms actually mediate the occurrence of clinical hallucinations, one would expect that hallucinating patients would more readily acquire and be more resistant to extinguish a conditioned hallucination than nonhallucinating psychotic patients. The present study examined the susceptibility of 15 hallucinating and 15 nonhallucinating acute schizophrenic inpatients to acquire and maintain a sensory-conditioned hallucination response. Consistent with the auditory sensory-conditioning model, evidence suggests that hallucinating patients acquire and maintain sensory-conditioned hallucinations more quickly than their nonhallucinating counterparts. Results are discussed in terms of hallucinators' susceptibility to sensory conditioning and suggestibility as important factors underlying hallucinatory behavior. The findings are interpreted with respect to the behavioral mechanisms underlying psychotic symptom formation.