ABSTRACT
This study tests the hypothesis that verbal hallucinations derive from “parasitic memories” which disrupt language production processes and episodically co-opts these processes. The study assumed that speech perception also accesses language production processes when the acoustic clarity of speech is reduced because subjects need to produce linguistic hypotheses regarding the meaning and formal organisation of the text in order to “fill in the gaps”. Subjects were requested to shadow prerecorded spoken texts whose phonetic clarity was reduced with multispeaker babbled. Patients with and without verbal hallucinations as well as a normal control group were studied. Hallucinators demonstrated much lower shadowing accuracy compared to the other two groups. Moreover, 4 out of 7 hallucinators “misheard” portions of target texts as verbalisations related to their voices. These data, although preliminary, point to specific language processing pathology underlying verbal hallucinations, and suggest the influence of parasitic verbal memories.
