title: ERP correlates of object recognition memory in Down syndrome: Do active and passive tasks measure the same thing?
abstract: Event related potentials (ERPs) can help to determine the cognitive and neural processes underlying memory functions and are often used to study populations with severe memory impairment. In healthy adults, memory is typically assessed with active tasks, while in patient studies passive memory paradigms are generally used. In this study we examined whether active and passive continuous object recognition tasks measure the same underlying memory process in typically developing (TD) adults and in individuals with Down syndrome (DS), a population with known hippocampal impairment. We further explored how ERPs in these tasks relate to behavioral measures of memory. Data-driven analysis techniques revealed large differences in old-new effects in the active versus passive task in TD adults, but no difference between these tasks in DS. The group with DS required additional processing in the active task in comparison to the TD group in two ways. First, the old-new effect started 150 ms later. Second, more repetitions were required to show the old-new effect. In the group with DS, performance on a behavioral measure of object-location memory was related to ERP measures across both tasks. In total, our results suggest that active and passive ERP memory measures do not differ in DS and likely reflect the use of implicit memory, but not explicit processing, on both tasks. Our findings highlight the need for a greater understanding of the comparison between active and passive ERP paradigms before they are inferred to measure similar functions across populations (e.g., infants or intellectual disability).
authors.affiliation: University of Arizona, Department of Psychology, 1503 East University Blvd., Tucson, AZ 85721, United States. Electronic address: a.h.vanhoogmoed@uu.nl.
authors.forename: A H
authors.initials: AH
authors.lastname: Van Hoogmoed
authors.affiliation: University of Arizona, Department of Psychology, 1503 East University Blvd., Tucson, AZ 85721, United States; University of Arizona, Cognitive Science Program, 1503 East University Blvd., Tucson, AZ 85721, United States.
authors.forename: L
authors.initials: L
authors.lastname: Nadel
authors.affiliation: University of Arizona, Department of Psychology, 1503 East University Blvd., Tucson, AZ 85721, United States; University of Arizona, Cognitive Science Program, 1503 East University Blvd., Tucson, AZ 85721, United States.
authors.forename: G
authors.initials: G
authors.lastname: Spanò
authors.affiliation: University of Arizona, Department of Psychology, 1503 East University Blvd., Tucson, AZ 85721, United States; University of Arizona, Cognitive Science Program, 1503 East University Blvd., Tucson, AZ 85721, United States; Sonoran University Center for Excellence in Developmental Disabilities, United States. Electronic address: jedgin@email.arizona.edu.
authors.forename: J O
authors.initials: JO
authors.lastname: Edgin
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D004314:Down Syndrome / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D055815:Young Adult
keywords: Active response; Down syndrome; Object recognition memory; Passive ERP; Permutation testing; Repetitions