title: Investigating the age-related "anterior shift" in the scalp distribution of the P3b component using principal component analysis.
abstract: An age-related "anterior shift" in the distribution of the P3b is often reported. Temporospatial principal component analysis (PCA) was used to investigate the basis of this observation. ERPs were measured in young and old adults during a visual oddball task. PCA revealed two spatially distinct factors in both age groups, identified as the posterior P3b and anterior P3a. Young subjects generated a smaller P3a than P3b, while old subjects generated a P3a that did not differ in amplitude from their P3b. Rather than having a more anteriorly distributed P3b, old subjects produced a large, temporally overlapping P3a. The pattern of the age-related "anterior shift" in the P3 was similar for target and standard stimuli. The increase in the P3a in elderly adults may not represent a failure to habituate the novelty response, but may reflect greater reliance on executive control operations (P3a) to carry out the categorization/updating process (P3b).
authors.affiliation: Center for Brain/Mind Medicine, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham, Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Brittany R
authors.initials: BR
authors.lastname: Alperin
authors.forename: Katherine K
authors.initials: KK
authors.lastname: Mott
authors.forename: Dorene M
authors.initials: DM
authors.lastname: Rentz
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Holcomb
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Daffner
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D025341:Principal Component Analysis; D011930:Reaction Time / Q000502:physiology; D012535:Scalp; D055815:Young Adult
keywords: Aging; Anterior shift; Cognition; EEG/ERP; P3; PCA