Semantic-episodic interactions in the neuropsychology of disbelief.

INTRODUCTION The purpose of this paper is to outline ways in which characteristics of memory functioning determine truth judgements regarding verbally transmitted information. METHOD Findings on belief formation from several areas of psychology were reviewed in order to identify general principles that appear to underlie the designation of information in memory as "true" or "false". RESULTS Studies on belief formation have demonstrated that individuals have a tendency to encode information as "true" and that an additional encoding step is required to tag information as "false". This additional step can involve acquisition and later recall of semantic-episodic associations between message content and contextual cues that signal that information is "false". Semantic-episodic interactions also appear to prevent new information from being accepted as "true" through encoding bias or the assignment of a "false" tag to data that is incompatible with prior knowledge. CONCLUSIONS It is proposed that truth judgements are made through a combined weighting of the reliability of the information source and the compatibility of this information with already stored data. This requires interactions in memory. Failure to integrate different types of memories, such as semantic and episodic memories, can arise from mild hippocampal dysfunction and might result in delusions.