West argues that the frontal aging hypothesis remains a useful construct, largely on the basis of evidence that cognitive functions dependent on frontal regions decline at an earlier age than those independent of frontal regions. This point was considered in my review, which found only sparse evidence in its favor. Few investigations have been aimed at determining the age at which decline begins for a set of functions. West cites one behavioral study (Shimamura & Jurica, 1994) and one PET study (Shaw et al., 1984). Given the size of the literature from which these studies are drawn, a finding of age effects in one “frontal” memory task with mean age 61 but not in one “nonfrontal” memory task can only suggest that age-related functional decline is more rapid in the frontal-dependent task. This finding must be viewed in the context of a broader range of functions. Several large scale studies aimed at this question have examined age-related declines on a broad range of functions and concluded verbal abilities are preserved until late in life while visuospatial abilities decline throughout adulthood (Arenberg, 1978; Eisdorfer et al., 1959; Koss et al., 1991). Shaw et al. (1984) must also be considered in the context of other studies of resting cerebral blood flow and metabolism which I reviewed which did not find selectively reduced prefrontal blood flow (Azari et al., 1992; Martin et al., 1991). Indeed, it is difficult either to prove or to disprove the somewhat vaguely-conceived frontal aging hypothesis using the current