title: Age-related change in neural processing of time-dependent stimulus features.
abstract: Aging is associated with changes in automatic processing of task-irrelevant stimuli, and this may lead to functional disturbances including repeated orienting to nonnovel events and distraction from task. The effect of age on automatic processing of time-dependent stimulus features was investigated by measurement of the auditory mismatch negativity (MMN) in younger (18-23) and older (55-85) adults. Amplitude of MMN recorded during a paradigm involving low-probability deviation in interstimulus interval (from 500 ms to 250 ms) was found to be reduced in the older group at fronto-central sites. This effect was paralleled by, and correlated to, decreased sensory gating efficiency for component N1 recorded during a separate paradigm involving alternate presentation of auditory stimuli at long (9 s) and short (0.5 s) interstimulus intervals. Further, MMN amplitude was correlated to behavioral performance on a small subset of neuropsychological tests, including the Rey Auditory Verbal Learning Test, within a group of healthy older adults. The results support the hypothesis that aging is associated with declines in automatic processing of time-dependent stimulus features, and this is related to cognitive function. These conclusions are considered in the context of age-related declines in prefrontal cortex function and associated increases in susceptibility to task-irrelevant stimuli.
authors.affiliation: Department of Psychology, University of Colorado at Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80933-7150, USA. mkisley@uccs.edu
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kisley
authors.forename: Deana B
authors.initials: DB
authors.lastname: Davalos
authors.forename: Laura L
authors.initials: LL
authors.lastname: Engleman
authors.forename: Paul M
authors.initials: PM
authors.lastname: Guinther
authors.forename: Hasker P
authors.initials: HP
authors.lastname: Davis
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography; D004594:Electrophysiology; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors; D014706:Verbal Learning / Q000502:physiology