Episodic Memory for Emotional and Neutral Pictures in Parkinson’s Disease

Objective: Prior studies have shown that individuals with Parkinson’s disease (PD) exhibit deficits in the processing of emotional information. Here, we investigated whether such deficits caused by PD reduce the mnemonic benefits typically produced by emotion in healthy individuals. Method: Thirty individuals with PD and 30 healthy individuals, matched for sex, age, and education, were recruited for the study. To assess their memory for emotional information, we asked them to observe a series of negative, positive, and neutral images distributed in three consecutive blocks. After a short interval, all observed images were presented again intermixed with new images, and the participants were asked to judge whether each image was “old” or “new” (i.e., recognition test), and to indicate the block in which each image was studied (i.e., source memory test). In addition, to characterize the sample, all participants responded to a series of neuropsychological and psychopathological tests. Results: As expected, individuals with PD exhibited diminished overall recognition and source memory scores relative to healthy controls (η2 p = 0.16 and 0.14, respectively). More importantly, while healthy controls showed greater recognition accuracy for negative versus neutral images (d = 0.65), this advantage was absent for PD participants (d < 0.18), a null effect corroborated by Bayesian analysis (BF01 = 3.34).