Context processing in older adults: Evidence for a theory relating cognitive control to neurobiology in healthy aging.

Abstract

A theory of cognitive aging is presented in which healthy older adults are hypothesized to suffer from disturbances in the processing of context that impair cognitive control function across multiple domains, including attention, inhibition, and working memory. These cognitive disturbances are postulated to be directly related to age-related decline in the function of the dopamine (DA) system in the prefrontal cortex (PFC). A connectionist computational model is described that implements specific mechanisms for the role of DA and PFC in context processing. The behavioral predictions of the model were tested in a large sample of older (N = 81) and young (N = 175) adults performing variants of a simple cognitive control task that placed differential demands on context processing. Older adults exhibited both performance decrements and, counterintuitively, performance improvements that are in close agreement with model predictions.There are a number of cognitive and biological changes that appear to occur during healthy aging. At the cognitive level, these changes include declines in functions such as episodic and working memory, attention, and inhibition (e.g

Localizing age-related individual differences in a hierarchical structure

“…First, the effect on the second-order common factor may be attributable to activity within the prefrontal cortex, possibly modulated by the level of a neurotransmitter, such as dopamine (e.g., Braver et al, 2001;Li, 2002). Second, the effect on the first-order memory factor might reflect functioning of the hippocampus and medial temporal lobe (e.g., Eustache et al, 1995;Golumb et al, 1994).…”

Cognitive control in media multitaskers

“…All other combinations-''A'' then not-''X'' (''AY''), not-''A'' then ''X'' (''BX''), and not-''A'' then not-''X'' (''BY'') were to be responded to with a ''no'' button press. In addition to the standard version of the AX-CPT, we administered a second version using distractor letters, identified by a different color, that intervened between cue and probe (14). In this version, participants were to ignore letters marked as distractors and to perform the task as if they did not exist.…”

A diffusion model analysis of adult age differences in episodic and semantic long-term memory retrieval.

“…Source memory tasks, by definition, make heavy demands on context memory, as do serial-order memory tasks and recall. The hypothesis that aging leads to disproportionate declines in context processing was first formulated in the early 1980s (e.g., Burke & Light, 1981;Rabinowitz & Ackerman, 1982) and continues to be a central theme of research on cognitive aging (e.g., Braver et al, 2001). Age differences in memory tasks tend to increase as a function of the tasks' reliance on memory for contextual detail (for empirical and theoretical reviews, see Light, 1996;2000b;Spaniol & Bayen, 2004;Spencer & Raz, 1995;Verhaeghen, Marcoen, & Goossens, 1993;Zacks et al, 2000).…”