title: Age-related effects on perceptual and semantic encoding in memory.
abstract: This study examined the age-related subsequent memory effect (SME) in perceptual and semantic encoding using event-related potentials (ERPs). Seventeen younger adults and 17 older adults studied a series of Chinese characters either perceptually (by inspecting orthographic components) or semantically (by determining whether the depicted object makes sounds). The two tasks had similar levels of difficulty. The participants made studied or unstudied judgments during the recognition phase. Younger adults performed better in both conditions, with significant SMEs detected in the time windows of P2, N3, P550, and late positive component (LPC). In the older group, SMEs were observed in the P2 and N3 latencies in both conditions but were only detected in the P550 in the semantic condition. Between-group analyses showed larger frontal and central SMEs in the younger sample in the LPC latency regardless of encoding type. Aging effect appears to be stronger on influencing perceptual than semantic encoding processes. The effects seem to be associated with a decline in updating and maintaining representations during perceptual encoding. The age-related decline in the encoding function may be due in part to changes in frontal lobe function.
authors.affiliation: Applied Cognitive Neuroscience Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China; Department of Applied Science, Hong Kong Institute of Vocational Education, Hong Kong, China.
authors.forename: M C C
authors.initials: MC
authors.lastname: Kuo
authors.affiliation: Applied Cognitive Neuroscience Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China; University of Western Sydney (School of Science and Health), Australia. Electronic address: Karen.Liu@uws.edu.au.
authors.forename: K P Y
authors.initials: KP
authors.lastname: Liu
authors.affiliation: Applied Cognitive Neuroscience Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: K H
authors.initials: KH
authors.lastname: Ting
authors.affiliation: Applied Cognitive Neuroscience Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China. Electronic address: Chetwyn.Chan@polyu.edu.hk.
authors.forename: C C H
authors.initials: CC
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time; D011932:Reading; D021641:Recognition, Psychology / Q000502:physiology*; D012660:Semantics; D013647:Task Performance and Analysis; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: aging; event-related potentials; perceptual encoding processing; semantic processing; subsequent memory effect