Source monitoring: ERP evidence for greater reactivity to nontarget information in older adults.

Event-Related Potentials (ERPs) were collected concurrently with stimulus presentation during a source monitoring task. Younger adults were less likely than older adults to make source monitoring errors and their ERP records showed far greater discrimination between target stimuli and familiar but nontarget foils. Older adults not only made more source errors but produced high amplitude late positivities to the nontarget foils even when these foils were correctly rejected. Under divided attention conditions, younger adults performance was similar to that of the older adults both behaviorally and electrophysiologically. These data illustrate the role that attentional resources play in the ability to inhibit response tendencies and suggest that age differences in source monitoring may be more related to attentional control than inefficiencies in the encoding of contextual information. As well, they suggest that the ERP late positivity may represent a more general response to item salience rather than serve as an index of recollection as is the current view.