title: I know I've seen you before: Distinguishing recent-single-exposure-based familiarity from pre-existing familiarity.
abstract: This study examines how individuals differentiate recent-single-exposure-based familiarity from pre-existing familiarity. If these are two distinct cognitive processes, are they supported by the same neural bases? This study examines how recent-single-exposure-based familiarity and multiple-previous-exposure-based familiarity are supported and represented in the brain using functional MRI. In a novel approach, we first behaviorally show that subjects can divide retrieval of items in pre-existing memory into judgments of recollection and familiarity. Then, using functional magnetic resonance imaging, we examine the differences in blood oxygen level dependent activity and regional connectivity during judgments of recent-single-exposure-based and pre-existing familiarity. Judgments of these two types of familiarity showed distinct regions of activation in a whole-brain analysis, in medial temporal lobe (MTL) substructures, and in MTL substructure functional-correlations with other brain regions. Specifically, within the MTL, perirhinal cortex showed increased activation during recent-single-exposure-based familiarity while parahippocampal cortex showed increased activation during judgments of pre-existing familiarity. We find that recent-single-exposure-based and pre-existing familiarity are represented as distinct neural processes in the brain; this is supported by differing patterns of brain activation and regional correlations. This spatially distinct regional brain involvement suggests that the two separate experiences of familiarity, recent-exposure-based familiarity and pre-existing familiarity, may be cognitively distinct.
authors.affiliation: Department of Psychology, The Hebrew University in Jerusalem, Mount Scopus, Jerusalem 91905, Israel; Department of Cognitive Sciences, The Hebrew University in Jerusalem, Mount Scopus, Jerusalem 91905, Israel. Electronic address: sigimbel@gmail.com.
authors.forename: Sarah I
authors.initials: SI
authors.lastname: Gimbel
authors.affiliation: Department of Neurosciences, University of California, San Diego, 8950 Villa La Jolla Drive, Suite C212, La Jolla, CA 92037, USA; Department of Radiology, University of California, San Diego, 8950 Villa La Jolla Drive, Suite C212, La Jolla, CA 92037, USA. Electronic address: jbrewer@ucsd.edu.
authors.forename: James B
authors.initials: JB
authors.lastname: Brewer
authors.affiliation: Department of Psychology, The Hebrew University in Jerusalem, Mount Scopus, Jerusalem 91905, Israel; Department of Cognitive Sciences, The Hebrew University in Jerusalem, Mount Scopus, Jerusalem 91905, Israel. Electronic address: anat.maril@mail.huji.ac.il.
authors.forename: Anat
authors.initials: A
authors.lastname: Maril
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D006801:Humans; D007600:Judgment / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011930:Reaction Time; D021641:Recognition, Psychology / Q000502:physiology*; D013998:Time Perception / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Familiarity; Functional connectivity; Medial temporal lobe; Recollection