Abstract
Using fMRI, we investigated reality monitoring for auditory information. During scanning, healthy young adults heard some words in another person’s voice and imagined hearing other words in that same voice. Later outside the scanner, participants judged words as heard, imagined or new. An area of left middle frontal gyrus (BA6) was more active at encoding for imagined items subsequently correctly called “Imagined” than items incorrectly called “Heard.” An area of left inferior frontal gyrus (BA45,44) was more active at encoding for items subsequently called “Heard” than “Imagined,” regardless of the actual source of the item. Scores on an Auditory Hallucination Experience Scale were positively related to activity in superior temporal gyrus (BA22) for imagined words subsequently incorrectly called “Heard.” We suggest that activity in these areas reflects cognitive operations information (middle frontal gyrus) and semantic and/or perceptual detail (inferior frontal gyrus, superior temporal gyrus, respectively) used to make source attributions.
