Experiential features used by patients with schizophrenia to differentiate 'voices' from ordinary verbal thought.

BACKGROUND: Determining how patients distinguish auditory verbal hallucinations (AVHs) from their everyday thoughts may shed light on neurocognitive processes leading to these symptoms. METHOD: Fifty patients reporting active AVHs ('voices') with a diagnosis of schizophrenia or schizo-affective disorder were surveyed using a structured questionnaire. Data were collected to determine: (a) the degree to which patients distinguished voices from their own thoughts; (b) the degree to which their thoughts had verbal form; and (c) the experiential basis for identifying experiences as voices versus their own verbal thoughts. Six characteristics of acoustic/verbal images were considered: (1) non-self speaking voice, (2) loudness, (3) clarity, (4) verbal content, (5) repetition of verbal content, and (6) sense of control. RESULTS: Four subjects were eliminated from the analysis because they reported absent verbal thought or a total inability to differentiate their own verbal thoughts from voices. For the remaining 46 patients, verbal content and sense of control were rated as most salient in distinguishing voices from everyday thoughts. With regard to sensory/perceptual features, identification of speaking voice as non-self was more important in differentiating voices from thought than either loudness or clarity of sound images. CONCLUSIONS: Most patients with schizophrenia and persistent AVHs clearly distinguish these experiences from their everyday thoughts. An adequate mechanistic model of AVHs should account for distinctive content, recognizable non-self speaking voices, and diminished sense of control relative to ordinary thought. Loudness and clarity of sound images appear to be of secondary importance in demarcating these hallucination experiences.

"Seeing voices": fused visual/auditory verbal hallucinations reported by three persons with schizophrenia-spectrum disorder.

OBJECTIVE: The neurocognitive basis of verbal/auditory hallucinations remains uncertain. A leading hypothesis is that these hallucinations correspond to ordinary inner speech mislabeled as non-self. However, some studies suggest pathogenic activation of receptive language neurocircuitry as the cause. A form of visualized verbal hallucinations not previously reported in the literature is described that may shed light on this controversy. METHOD: Review of three cases. RESULTS: Two patients described visual hallucinations of speech-like lip and mouth movements fused with simultaneous auditory verbal hallucinations superimposed on perceptions of faces of actual persons in their immediate environment. A third patient described similar experiences incorporated into visual hallucinations of human figures who also exhibited finger and hand movements corresponding to American Sign Language. CONCLUSION: These fused, multimodal verbal hallucinations seem unlikely to be due to inner speech mislabeled as non-self, and instead suggest top-down re-shaping of activation in visual processing brain centers by pathogenically active receptive language neurocircuitry.