title: Age-related differences in early novelty processing: using PCA to parse the overlapping anterior P2 and N2 components.
abstract: Previous work demonstrated age-associated increases in the anterior P2 and age-related decreases in the anterior N2 in response to novel stimuli. Principal component analysis (PCA) was used to determine if the inverse relationship between these components was due to their temporal and spatial overlap. PCA revealed an early anterior P2, sensitive to task relevance, and a late anterior P2, responsive to novelty, both exhibiting age-related amplitude increases. A PCA factor representing the anterior N2, sensitive to novelty, exhibited age-related amplitude decreases. The late P2 and N2 to novels inversely correlated. Larger late P2 amplitude to novels was associated with better behavioral performance. Age-related differences in the anterior P2 and N2 to novel stimuli likely represent age-associated changes in independent cognitive operations. Enhanced anterior P2 activity (indexing augmentation in motivational salience) may be a compensatory mechanism for diminished anterior N2 activity (indexing reduced ability of older adults to process ambiguous representations).
authors.affiliation: Center for Brain/Mind Medicine, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA. Electronic address: kdaffner@partners.org.
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Daffner
authors.affiliation: Center for Brain/Mind Medicine, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Brittany R
authors.initials: BR
authors.lastname: Alperin
authors.affiliation: Center for Brain/Mind Medicine, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Katherine K
authors.initials: KK
authors.lastname: Mott
authors.affiliation: Center for Brain/Mind Medicine, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Erich S
authors.initials: ES
authors.lastname: Tusch
authors.affiliation: Department of Psychology, Tufts University, 490 Boston Avenue, Medford, MA 02155, USA.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Holcomb
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D025341:Principal Component Analysis; D011597:Psychomotor Performance / Q000502:physiology; D055815:Young Adult
keywords: Aging; Anterior N2; Anterior P2; Mismatch; Motivational salience; Novelty; PCA