In defense of the frontal lobe hypothesis of cognitive aging

Over the past decade a number of reviewers have argued that the pattern of spared and impaired cognitive functions observed in the cognitive aging literature can be understood within the context of a neuropsychologically constrained model that proposes that the prefrontal cortex is more vulnerable to the effects of normal aging than other cortical regions (Dempster, 1992; Hartley, 1993; Moscovitch & Winocur, 1992; West, 1996). While this model has served as a valuable heuristic in my own thinking about cognitive aging, the current review of Greenwood and theoretical work emerging from other laboratories argues that the “frontal lobe hypothesis” (FLH) no longer provides a useful or accurate framework within which to understand brain behavior relationships in cognitive aging. While I agree with several of the ideas developed in the review of Greenwood (this issue) I believe the continued utility of the FLH can be demonstrated by considering two questions: (1) What does the FLH predict about cognitive aging and is there support for these predictions? and (2) Has the time come to move beyond a general specification of the FLH? In answering these questions I will provide one or two findings from the empirical literature. These are intended to be illustrative, not exhaustive.