Functional activity changes in memory and emotional systems of healthy subjects with déjà vu

Abstract Deja vu(DV) is a fascinating and mysterious human experience that has attracted interest from psychologists and neuroscientistsfor over a century. In recent years, several studies have been conducted to unravel the psychological and neurological correlates of this phenomenon. However, the neural mechanisms underlying the DV experience in benign manifestations are still poorly understood. Thirty-three healthy volunteers completed an extensive neuropsychiatric and neuropsychological battery including personality evaluation. The presence of DV was assessed with the Inventory for Deja vuExperiences Assessment. Participants underwent episodic memorylearning test, and 2 days later during event-related functional magnetic resonance imaging(fMRI), they are asked to rate old and new pictures as a novel, moderately/very familiar, or recollected. We identified 18 subjects with DV (DV +) and 15 without DV (DV −) matched for demographical, neuropsychological, and personality characteristics. At a behavioral level, no significant difference was detected in the episodic memorytasks between DV + and DV −. Functional magnetic resonance imaginganalysis revealed that DV +, independently from task conditions, were characterized by increased activity of the bilateral insulacoupled with reduced activation in the right parahippocampal, both hippocampi, superior/middle temporal gyri, thalami, caudate nuclei, and superior frontal gyri with respect to DV −. Our study demonstrates that individuals who experienced DV are not characterized by different performance underlying familiarity/recollection memory processes. However, fMRI results provide evidence that the physiological DV experience is associated with the employment of different neural responses of brain regions involved in memory and emotional processes.