title: Changes in pattern completion--a key mechanism to explain age-related recognition memory deficits?
abstract: Accurate memory retrieval from partial or degraded input requires the reactivation of memory traces, a hippocampal mechanism termed pattern completion. Age-related changes in hippocampal integrity have been hypothesized to shift the balance of memory processes in favor of the retrieval of already stored information (pattern completion), to the detriment of encoding new events (pattern separation). Using a novel behavioral paradigm, we investigated the impact of cognitive aging (1) on recognition performance across different levels of stimulus completeness, and (2) on potential response biases. Participants were required to identify previously learned scenes among new ones. Additionally, all stimuli were presented in gradually masked versions to alter stimulus completeness. Both young and older adults performed increasingly poorly as the scenes became less complete, and this decline in performance was more pronounced in elderly participants indicative of a pattern completion deficit. Intriguingly, when novel scenes were shown, only the older adults showed an increased tendency to identify these as familiar scenes. In line with theoretical models, we argue that this reflects an age-related bias towards pattern completion.
authors.affiliation: German Center for Neurodegenerative Diseases (DZNE), Aging and Cognition Research Group, Magdeburg, Germany. Electronic address: paula.vieweg@dzne.de.
authors.forename: Paula
authors.initials: P
authors.lastname: Vieweg
authors.affiliation: German Center for Neurodegenerative Diseases (DZNE), Aging and Cognition Research Group, Magdeburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Stangl
authors.affiliation: German Center for Neurodegenerative Diseases (DZNE), Aging and Cognition Research Group, Magdeburg, Germany.
authors.forename: Lorelei R
authors.initials: LR
authors.lastname: Howard
authors.affiliation: German Center for Neurodegenerative Diseases (DZNE), Aging and Cognition Research Group, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wolbers
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008569:Memory Disorders / Q000503:physiopathology*; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: Cognitive aging; Hippocampus; Memory retrieval; Pattern completion bias; Recognition memory deficit