AGE, COLOR PROCESSING AND MEANINGFULNESS - AN EVENT-RELATED POTENTIALSTUDY

The effects of aging on event-related potentials (ERPs) and reaction t ime (RT) performance were investigated in a task that combined color d iscrimination and lexical decision. The stimuli were either words or n on-words, presented either in the relevant or in the irrelevant color. RT responses were required to words in the relevant color. Stimuli ap peared in the relevant color elicited attention-related ERP components (anterior positivity, selection negativity and N2b). The latency valu es of the attention-related ERP components and the RT were longer in t he older group, indicating the slowing down of attentional processes i n the elderly. In the older group the late positivity to stimuli in th e relevant color was absent over the posterior locations. Unlike in th e older group, in the younger subjects the words appeared in the irrel evant color elicited a central negative wave in the 400 ms range. Thes e results are considered as a capacity limitation in the elderly in pr ocessing of the stimulus characteristics beyond to the actual stimulus -response contingencies.