Examining the relationships between cognition and auditory hallucinations: A systematic review

Area of Science:

• Cognitive Neuroscience
• Psychiatry
• Psychology

Background:

• Auditory hallucinations (hearing voices) are linked to various cognitive alterations, but empirical evidence is inconsistent.
• Theoretical models persist, emphasizing a multidimensional framework for understanding these phenomena.
• Clarification of current evidence across proposed cognitive mechanisms is needed.

Purpose of the Study:

• To systematically review and clarify the empirical evidence linking auditory hallucinations to specific cognitive functions.
• To evaluate the consistency of findings across different cognitive domains.
• To identify limitations in current research methodologies and suggest future directions.

Main Methods:

• Systematic literature search of Web of Science, PubMed, and Scopus databases.
• Screening of records for studies using objective behavioral cognitive tasks and valid auditory hallucination measures.
• Analysis of findings within predictive coding and self-monitoring frameworks.

Main Results:

• Auditory hallucinations strongly associated with impaired perceptual decision-making, source-monitoring, working memory, and reduced verbal fluency.
• Mixed or limited support found for associations with perceptual feature discrimination, imagery, certain aspects of source-monitoring, memory recall, executive functions, emotion processing, and language comprehension.
• Disparities noted between theoretical models and empirical evidence, with some studies using non-specific measures or broad diagnostic contrasts.

Conclusions:

• The review highlights inconsistencies in research on auditory hallucinations, particularly regarding cognitive mechanisms.
• Methodological concerns include the use of modality-general measures and broad diagnostic comparisons.
• Future research should precisely define and measure hallucination timeframe and sensory modality, extending beyond the schizophrenia spectrum.