Cognitive and perceptual mechanisms in clinical and non-clinical auditory hallucinations

[Truncated abstract] Auditory hallucinations (AH) are one of the most persistent, distressing, and functionally disabling symptoms of schizophrenia. Despite significant research into aetiology and treatment, the full picture of the mechanisms involved in these experiences remains unclear. AH also occur relatively frequently in healthy individuals in the general population, supporting a continuum model of psychotic symptoms. However, there have been recent challenges to this view, including evidence of important differences in the phenomenology and cognitive mechanisms in patient and non-patient voice hearers. The overarching goal of this thesis is to advance our understanding of the commonalities and differences in cognitive and perceptual mechanisms underlying clinical and non-clinical AH. One of the core features of AH involves them being experienced as separate from one’s own mental processes. These experiences have predominantly been explained by failures of self-recognition, or reality monitoring difficulties; however evidence points to a broader array of context memory impairments in AH. The first part of this thesis sought to explore the exact nature of context memory deficits in clinical and non-clinical AH. By assessing memory binding of voice and location information, the first two experiments revealed that healthy, hallucination-predisposed individuals are not impaired in either automatic or intentional binding of two external, contextual features of information in memory. In order to make firm conclusions about whether context memory impairments are/are not present in non-clinical compared to clinical AH, the third experiment applied an identical word-voice memory binding task in two separate studies of: (1) hallucination-prone individuals, and (2) schizophrenia patients (with and without AH).