Previous studies have shown age-associated deficits in selective attention
that vary as a function of task demands. The present study was conducted to
dissociate the effect of task complexity on age-related performance differ
ences from qualitative differences in cognitive demands. Twenty-four young
and 24 older adults were administered two versions of the Stroop Test (Hart
ley, 1993). The Color-Block version required identifying the color of a box
while ignoring the name of a color printed either above or below the box.
The Color-Word version required naming the color of a word while ignoring t
he semantic meaning of the word (a color name). Each version of the task in
cluded a two- and four-color choice condition as a manipulation of task com
plexity Old and young adults Performed comparably on the Color-Block Task,
but older adults were significantly impaired an both conditions of the Colo
r-Word Task, particularly in the four-choice condition. Results suggest age
-related differences in the distinct attentional processes demanded by each
task are not attributable to general slowing.