title: Severely deficient autobiographical memory (SDAM) in healthy adults: A new mnemonic syndrome.
abstract: Recollection of previously experienced events is a key element of human memory that entails recovery of spatial, perceptual, and mental state details. While deficits in this capacity in association with brain disease have serious functional consequences, little is known about individual differences in autobiographical memory (AM) in healthy individuals. Recently, healthy adults with highly superior autobiographical capacities have been identified (e.g., LePort, A.K., Mattfeld, A.T., Dickinson-Anson, H., Fallon, J.H., Stark, C.E., Kruggel, F., McGaugh, J.L., 2012. Behavioral and neuroanatomical investigation of Highly Superior Autobiographical Memory (HSAM). Neurobiol. Learn. Mem. 98(1), 78-92. doi: 10.1016/j.nlm.2012.05.002). Here we report data from three healthy, high functioning adults with the reverse pattern: lifelong severely deficient autobiographical memory (SDAM) with otherwise preserved cognitive function. Their self-reported selective inability to vividly recollect personally experienced events from a first-person perspective was corroborated by absence of functional magnetic resonance imaging (fMRI) and event-related potential (ERP) biomarkers associated with naturalistic and laboratory episodic recollection, as well as by behavioral evidence of impaired episodic retrieval, particularly for visual information. Yet learning and memory were otherwise intact, as long as these tasks could be accomplished by non-episodic processes. Thus these individuals function normally in day-to-day life, even though their past is experienced in the absence of recollection.
authors.affiliation: Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada M6A 2E1; Department of Psychology, University of Toronto, Toronto, ON, Canada M5S 1A1.
authors.forename: Daniela J
authors.initials: DJ
authors.lastname: Palombo
authors.affiliation: Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada M6A 2E1; Department of Psychology, University of Toronto, Toronto, ON, Canada M5S 1A1.
authors.forename: Claude
authors.initials: C
authors.lastname: Alain
authors.affiliation: Department of Psychology, Uppsala University, Uppsala 751 42, Sweden.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Söderlund
authors.affiliation: Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada M6A 2E1; Department of Psychology, University of Toronto, Toronto, ON, Canada M5S 1A1.
authors.forename: Wayne
authors.initials: W
authors.lastname: Khuu
authors.affiliation: Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada M6A 2E1; Department of Psychology, University of Toronto, Toronto, ON, Canada M5S 1A1; Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada M5S 1A1. Electronic address: blevine@research.baycrest.org.
authors.forename: Brian
authors.initials: B
authors.lastname: Levine
mesh_terms: D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D003463:Cues; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000098:blood supply / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000473:pathology* / Q000503:physiopathology*; D061212:Memory, Episodic; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D018709:Statistics, Nonparametric; D014706:Verbal Learning / Q000502:physiology
chemical_list: D010100:Oxygen
keywords: Autobiographical memory; Case study; Episodic memory; Hippocampus