title: Object individuation and compensation in healthy aging.
abstract: Theories on neural compensation suggest that aged participants overactivate the brain areas involved in a task to compensate for the age-related decline. In this electrophysiological study, we investigated the temporal locus of neural overactivation in aging during multiple target processing. We measured performance and three event-related brain potential responses (N1, N2pc, and contralateral delay activity) in young and old adults, while they enumerated a variable number (1-4) of targets presented in an easy (distractor absent) or difficult (distractor present) condition. The main results indicated that although N2pc (∼200 ms) increased in amplitude in the distractor-present condition in the young group, no modulation occurred for the old group. Old participants were associated with larger N2pc amplitudes than young participants in the distractor-absent condition, where both groups had comparable levels of accuracy. These effects were not present for N1 and contralateral delay activity. Overall, the data suggest that in enumeration, aging is associated with compensatory effects that rely on the selection mechanism responsible for target individuation.
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN), Italy. Electronic address: silvia.pagano@unitn.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Pagano
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN), Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Fait
authors.affiliation: IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
authors.forename: Debora
authors.initials: D
authors.lastname: Brignani
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN), Italy; IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; Department of Psychology and Cognitive Science, University of Trento, Rovereto (TN), Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Mazza
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D001519:Behavior / Q000502:physiology; D001921:Brain / Q000502:physiology*; D004526:Efficiency / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D009483:Neuropsychological Tests; D011930:Reaction Time; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: Aging; ERPs; Multiple object processing; Neural compensation