Is auditory imagery defective in patients with auditory hallucinations?

Background. A variant of the 'inner speech' theory of auditory verbal hallu cinations in schizophrenia suggests that there is an abnormality of the rel ationship between the 'inner voice' and 'inner ear', such that hallucinator s are unable to distinguish inner 'imagined' speech from real external spee ch, and so misrecognize inner speech as alien. Methods. Five experiments were carried out comparing 12 schizophrenic patie nts who were highly prone to hallucinate, with seven patients who were not, on a series of auditory imagery tasks that are differentially dependent on inner voice/inner ear partnership for successful performance: parsing mean ingful letter/number strings; the verbal transformation effect; phoneme jud gements; pitch judgements, and homophony and rhyme judgements. Results. Contrary to our hypothesis, there was no evidence that the group w ith the propensity to hallucinate were impaired on tasks requiring normal i nner ear/inner voice partnership. Conclusions. Together with previous work indicating no impairment of the ph onological loop in patients who hallucinate, these results suggest that inn er speech and auditory verbal hallucinations are not connected in a simplis tic or direct way. Indeed, a reappraisal of psychological models of halluci nations in general may be warranted.