Toward Understanding Age-Related Memory Loss in Late Adulthood

Abstract

Background: While laboratory tests indicate that older adults typically perform more poorly than do younger adults on many types of memory tasks, the question arises as to whether, or to what extent, it is valid to attribute these differences to ageing per se or to some variable or class of variables that intervene between age and remembering. Objective: The purpose of this review is to present three current views that might explain the relationship between age and remembering. They can be construed as variants on resource theories and include: the processing speed hypothesis, the executive function hypothesis, and the common cause hypothesis. Methods: The review samples results pertinent to these hypotheses that derive from behavioural research. Studies involving various imaging techniques were considered beyond the scope of the review. Results: The balance of research strongly implicates reductions in the speed of information processing as a fundamental contributor to normal age-related memory loss. Nonetheless there are circumstances where other mechanisms, such as working memory, executive function, and sensory processes, are important. Conclusion: Despite the phenomenological and empirical reality of age-related memory loss and the breadth of attempts to explain it, much work remains to be done to understand why it occurs. Contemporary debates about the nature and means of identifying shared and unique effects promise to shape future directions for research on memory aging.

Cognitive Ability, Expertise, and Age Differences in Following Air-Traffic Control Instructions.

“…More definitive psychometric and factor analytic work is sorely needed in this area, as many measures of inhibitory control, task switching behavior, and the like (including the Shifting Attention test) lack established reliability and construct validity. That these measures should not largely overlap with general speed of processing measures is a refrain vocalized by numerous previous investigators (Bryan & Luszcz, 2000;Burke, 1997;Luszcz & Bryan, 1999;McDowd, 1997;Park et al, 1996;Rabbitt, Lowe, & Shilling, 2001;Salthouse, 1999).…”

Understanding Ageing

“…visual and auditory acuity), respectively. Although few would consider aging to be a simple and general process for all types of functioning, the evaluation of common and specific age associations among age-related processes are emphasized in research on cognitive aging and usually involve cross-sectional research designs and variance partitioning approaches [5][6][7][8][9]. In general, however, large proportions of shared age-related variance among diverse variables are found in such studies although there have been reports of unique proportions of age-related variance for particular variables [10][11][12].…”

The Clinical Problem of Symptomatic Alzheimer Disease and Mild Cognitive Impairment

“…Short-term memory loss (exemplified by free recall of a list of words or stories; Gilbert and Levee 1971;Crook and West 1990), with relative preservation of immediate (Blum et al 1970;Drachman and Leavitt 1972) and longterm memory (Luszcz and Bryan 1999) has been reported in healthy elderly as early as the sixth decade. Memory decline in early AD, as opposed to what occurs with normal aging, represents a consistent and progressive change from the individual's prior abilities, and often results in mild impairment in daily functions (Morris 1993).…”