“…The differential decline in verbal and nonverbal abilities initiated the hypothesis that the right hemisphere ages more rapidly than does the left hemisphere (Goldstein & Shelly, 1981). However, the findings of cognitive and perceptual studies that have examined cerebral lateralization among the elderly are inconsistent.Several studies do not provide evidence for an age-related differential decline, favoring the left hemisphere (Borod & Goodglass, 1980;Brown & Sainsbury, 2000;Cherry, Hellige, & McDowd, 1995;Hoyer & Rybash, 1992;Nebes, Madden, & Berg, 1983), whereas other studies report an age-related differential decline, favoring the left hemisphere (Boll, 1974;Goldstein & Shelly, 1981; R. C. Johnson et al, 1979;Klisz, 1978;Meudell & Greenhalgh, 1987). However, other factors, such as task complexity, familiarity of task and materials, and speed (timed tasks), have been noted to affect age differences in performance (see Horn & Hofer, 1992).…”