Cognitive vulnerability to auditory hallucination. Preferred imagery mode and spatial location of sounds

Goldstone and Sarbin proposed that auditory hallucinations occur because imagery in a non-preferred sensory mode is more easily misinterpreted as having an external origin. This led to the hypothesis that auditory hallucinators would show less preference for auditory than for visual imagery. Our results suggest that this is true. We also compared the vividness of internally-generated auditory imagery with that of visual imagery, independently of preference, to see whether vividness was impaired in the nonpreferred mode in hallucinators. The evidence suggested that this was not the case, but we did find a significantly deficient capacity for creating vivid images of either kind in process patients (i.e. those with poor premorbid status) compared with reactive (good premorbid) patients, regardless of any history of hallucinations. The withdrawal of external attention which characterizes process patients might also be expected to impair their ability to confirm or disconfirm the external origin of an auditory stimulus. We predicted therefore that process hallucinators would be particularly incompetent in spatial location of sounds: our experimental results confirmed this to be the case.