PREFRONTAL DEFICITS IN ATTENTION AND INHIBITORY CONTROL WITH AGING

Event-related potentials and behavioral measures were obtained from yo ung and elderly subjects while they performed two different auditory d elayed match-to-sample tasks. In each experiment, subjects had to indi cate whether an initial and a subsequent test sound were identical in two different conditions: one filled with distracting tone pips and on e with no distracters. Electro physiologically, elderly subjects had r educed attention-related activity over frontal regions. In addition, t he distracting stimuli elicited an enhanced primary auditory evoked re sponse in the elderly. The percentage of perseverative errors on the W isconsin card sorting test, a putative measure of frontal lobe functio n, was positively correlated with the amplitude of the primary auditor y evoked response in elderly subjects. Behaviorally, elderly subjects were impaired by distracters at long but not short delays. Taken toget her, these results suggest that increased distractibility and impaired sustained attention with aging may be due to altered prefrontal corte x function. These data support the loss of prefrontal suppression over the primary auditory regions with aging.