title: Lateral posterior parietal activity during source memory judgments of perceived and imagined events.
abstract: Memories of real and imagined events are qualitatively distinct, and therefore may be supported by different neural mechanisms. In the present study, we tested whether brain regions are differentially activated during source discriminations of perceived versus imagined events. During the encoding phase, subjects perceived and imagined images of objects in response to a cue word. Then, at test, they made judgments about whether old and new cue words corresponded to items that were previously perceived or imagined, or if they were new. The results demonstrated that the left lateral posterior parietal cortex and dorsolateral prefrontal cortex were significantly more active during source attributions of perceived compared to imagined events. In addition, activity in these regions was associated with successful item memory (hits>correct rejections) for perceived, but not imagined events. These findings of a source-based dissociation of successful retrieval activity have important implications regarding theories of parietal contributions to recognition memory.
authors.affiliation: Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA. Electronic address: king@psych.ucsb.edu.
authors.forename: Danielle R
authors.initials: DR
authors.lastname: King
authors.affiliation: Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Miller
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007600:Judgment / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology; D011930:Reaction Time; D021641:Recognition, Psychology / Q000502:physiology; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: Lateral posterior parietal cortex (PPC); Parietal old/new effects; Reality monitoring; Source memory; Successful retrieval