Question

what is memory? How is memory affected across the life span?

Answer 1

Memory is the faculty of the brain by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. Knowledge and access to knowledge is well preserved in adulthood. It declines rather late in life, more precociously with pathologies of memory than with normal aging. Several factors that influence memory development such as changes in the brain regions envisioned by Lindenberger and collegues in their life span theory of memory development.Although space precludes a detailed treatment of other influences.We treat briefly two other aspects: a psychological account of memory development based on the concept of cognitive resources, and the infl uence of pathological memory change in later life.
Cognitive Resources
By some accounts, basic processing mechanisms can be viewed as resources that can be flexibly allocated in service of achieving cognitive goals. Here, we selectively discuss two basic cognitive resources (i.e., WM and processing speed) that received considerable attention in both fi elds of cognitive development and aging. WM is a critical resource for encoding information into episodic memory, as well as other higher-order forms of cognition such as inductive reasoning (e.g., Kyllonen & Christal, 1990; Hultsch et al., 1998; Salthouse, 1991). Developmental changes in WM have been cited as a major cause ofhigher cognitive development in children (Gathercole, 1998) and as a cause of age-related decline in episodic memory (Salthouse & Babcock, 1991; Stine-Morrow et al., 2006). WM changes are highly associated with episodic memory changes in adulthood (Hertzog et al., 2003; Hultsch et al., 1998). Theories of cognitive development emphasizing the role of processing speed have also been formulated for both ends of the life span (Birren, 1965; Kail & Salthouse, 1994; Salthouse, 1996). For instance, Kail and Park (1994) showed that there is a relationship between processing speed and memory span mediated by articulation rate. In aging, cross-sectional studies have found that between 44 and 80% of cross-sectional age variance in memory task was associated with psychometric tests of perceptual speed (Salthouse, 1996; Verhaeghen & Salthouse, 1997). However, reduced resource explanations of aging have been challenged on several grounds, including (1) the measurement properties and cognitive constituents of tests of processing speed (e.g., Hertzog, 1989; Lustig, Hasher, & Tonev, 2006);
(2) whether one of these information-processing constructs is more basic than the variables they are used to predict (Deary, 2001; Light, 1991); and (3) methodological problems with regression-based estimates of resource-determined age-related variance using cross-sectional data (Hofer, Flaherty, & Hoffman, 2006; Lindenberger & Pötter, 1998). For example, longitudinal data typically show smaller effects of changes in speed and WM on changes in episodic memory performance (Hertzog et al., 2003; Hultsch et al., 1998).