Hallucinatory modalities in prelingually deaf schizophrenic patients: a retrospective analysis of 67 cases.

In order to examine the effect of congenital or early acquired deafness on hallucinatory modalities in schizophrenia, we interviewed 67 prelingually deaf schizophrenic patients (using sign language) about their hallucinatory experiences over the entire course of their illness. We also analysed the clinical records of our subjects' previous hospitalizations. In our deaf sample, visual and tactile hallucinations were plainly over-represented as hallucinatory modalities in comparison with hearing schizophrenic samples. Although some patients reported visual hallucinatory perceptions of sign language messages, the hallucinatory reception of meaningful information in deaf patients seems also to remain affiliated to the 'auditory' modality. It was concluded that the different representation of hallucinatory modalities reflects in particular the influence of 'the deaf way' of sensory experience on imagery processes.