The processing-speed theory of adult age differences in cognition

“On the other hand, young adults performed significantly better on the digit comparison task (Hedden et al., 2002), a measure assessing participants' speed of processing (Salthouse, 1996), than the older adults, t(62) ϭ 4.45, p Ͻ .001.”

“While this main effect of age group was not significant in follow-up analyses that covaried measures of processing speed, age and processing speed are inextricably linked in real-world settings (Salthouse, 1996).”

“The difference in processing speed was particularly surprising as the LOS group was, on average, 6 years older than the EOS group, and processing speed tends to decline steadily with normal aging (86).”

“, Adams, 1991; Carstensen & Turk-Charles, 1994; Hess, 1999), most hypotheses concerning the source of this age-related variability in representational processes are based in decrements in basic cognitive functions, such as processing speed (Salthouse, 1996), inhibitory functions (Hasher & Zacks, 1988), or working memo…”

“The slower rate also allowed us to observe whether old adults may be able to attenuate false recall across multiple study–test trials under the slower rate; this possibility is entertained in view of findings of age differences in processing speed (Salthouse, 1996).”

“…is closely related to the ability to perform higher-order cognitive tasks (Lichtenberger and Kaufman, 2012) and is often assumed to be the core issue responsible for deficits in performance on complex cognitive measures in aging populations (Salthouse, 1996; Salthouse and Ferrer-Caja, 2003).”

“Our longitudinal CVR data revealed a similar association between changes in CVR and processing speed, the most sensitive cognitive marker of aging (Park et al., 2002; Salthouse, 1996), using a sample size that was substantially smaller.”

“The persistence of this pattern of results, across numerous studies suggest that the pervasive age-related slowing observed across many different kinds of behavioral tasks (e.g., Myerson et al., 1990; Salthouse, 1996) may result from a fundamental change in brain-behavior relationships with age.”

“An explanation of how processing speed might influence memory has been described by Salthouse (1996) who suggested that the speed at which the central nervous system processes information could influence not only the quantity but also the quality of memory performance.”

“, learned and practiced knowledge), research also suggests a negative relationship between age and fluid intelligence (i.e., the ability to think critically and solve novel problems; Horn & Cattell, 1967; Salthouse, 1996; Schaie, 1996).”

“The relationship between chronological age and performance corresponds to that what is typically found in the literature (e.g., McArdle, Ferrer-Caja, Hamagami, & Woodcock, 2002; Salthouse, 1996).”

“…pattern disrimination and complex stimuli (for review, see Salthouse, 1994). n an attempt to generate an underlying account of such diverse eficits, the findings of many behavioral studies on older adults ave given rise to the processing speed hypothesis of cognitive ging (Salthouse, 1996).”

“The increased length of the reaction times in the older adults, although not significantly different from those of the younger group, reflect classical findings of age-related slowing during task performance (Birren, 1965; Salthouse, 1996).”

“Intact information processing speed in patients with fibromyalgia suggests specific neurologic/ cognitive deficits rather than the global neurologic decline more characteristic of older adults [14]; impaired processing speed is a feature of cognitive aging [38–40].”

“are slower than younger adults in many cognitive tasks, with an initial—and prominent—explanation of this phenomenon being the “cognitive slowdown” account, where older adults had slower mental processing than younger adults (Salthouse, 1996).”

“In fact, effect sizes for the computer-administered WCST measures in this study were similar to those found bv Salthouse et al. (1996), who used the standard pup", "-i version of the WCST.”

“Some theorists have used statistical methods (e.g., factor analysis) to look for clusters of abilities that tap working memory (e.g., Carrol, 1993; Kyllonen, 1995) while others have offered qualitative descriptions of proposed working memory mechanisms (e.g., Baddeley, 1986; Salthouse, 1996).”

“A more elaborated version of the slowed processing hypothesis, developed to account for age e€ects in cognition [40], may also be able to account for the results of this study.”

“Older adults experience age-related cognitive changes that may impede their ability to process and remember information (Brown&Park, 2003; Kessels, 2003), as they often process information more slowly (Salthouse, 1996) and have reduced working memory capacity (Bopp& Verhaeghen, 2005; Grady & Craik, 2000).”

“This has lead to various theories that attempt to describe and account for the changes in cognitive function in old age, centering on reductions in available processing resources (Craik, 2002), general slowing of processing (Salthouse, 1996), declines in working memory capacity (McCabe, Smith, & Parks, 2007; Park et a…”

“…manipulations should have a greater effect on older adults due to (a) age-related slowing of perceptual processing (Faust et al., 1999; Madden, 2001; Salthouse, 1996, 2000) and (b) in some cases insufficient cognitive/neural top-down mechanisms, as a result of age-related neural degeneration (Raz…”

“As noted above, some theoretical accounts propose a global deficit in memory aging (e.g., Benjamin, 2010; Salthouse, 1996) whereas others propose age deficits exist mainly or entirely for specific cognitive processes, such as remembering the source or context of information (e.g., Jennings &…”

“Although cognitive slowing has been proposed as the factor underlying more general cognitive decline in old age (Salthouse, 1996), age-related increase in variability has been noted in the literature for some time (Christensen et al.”

“According to Salthouse’s processing-speed theory (34), cognitive performance is degraded when processing is slow because the products of early processing may no longer be available when later processing is complete (i.”

“For example, older adults generally process information more slowly than younger adults, and this reduced rate of processing is posited to be a fundamental cause of age differences in cognitive performance (Salthouse, 1996).”

“This may be due to the mental reassembly process of the visual and tactile information becoming slightly slower with age, similar to effects previously observed [ 20 ], or to a certain loss in tactile perception as the experiment progresses.”

“These include general processing speed (Salthouse, 1996), declines in the capacity of working memory (Hultsch et al., 1998; Salt-house, 1991; Wingfield et al., 1988), reduced efficiency in inhibiting off-target thoughts and stimuli (Hasher & Zacks, 1988; Zacks et al., 2000), declining effectiveness…”

“Furthermore, older workers are more likely to have slower processing speed (Salthouse, 1991, 1996); therefore, it makes sense that having enough time and autonomy to do the job will help reduce the likelihood of experiencing stress associated with stringent deadlines.”

“…the changes in cognitive function in old age, centering on reductions in available processing resources (Craik, 1982, 2002), general slowing of processing (Myerson, Hale, Wagstaff, Poon, & Smith, 1990; Salthouse, 1996), and reductions in inhibitory control (Hasher & Zacks, 1988; Rabbitt, 1965).”

“In the study of cognitive ageing, perhaps the most well known finding is that processing ability declines with advancing age even in the absence of pathology (Park, Lautenschlager, Hedden, Davidson, Smith, & Smith, 2002; Rabbitt & Lowe, 2000; Salthouse, 1996).”

“…window of integration becomes larger (Diederich, Colonius, & Schomburg, 2008) possibly in order to partially compensate for age-related decline in sensory acuity in peripheral sensory organs (Owsley, 2011) or for the general cognitive slowing characterising late adulthood (Salthouse, 1996, 2009).”

“…Gabrieli, 2004; Schaie, 1996) whereas domains such as working memory (Craik, 1994; Park et al., 2002; Wing fi eld et al.,1988), executive control (Dempster,1992; Hasher et al.,1999; Lamar et al., 2002) and processing speed (Deary et al., 2010; Salthouse, 1991, 1996) are more vulnerable to decline.”

“Processing speed accounts for the link between working memory and g in some studies (Fry & Hale, 1996; Jensen, 1998; Kail & Salthouse, 1994; Salthouse, 1996), while others have found that working memory is the primary predictor of g, even while controlling for processing speed (Carpenter, Just, & Shell, 1990; Conway,…”

“In both conditions, the latency of the P300 was longer in the older participants, in accord with their longer reaction times, supporting the idea that there is a slowing of cognitive performance with advancing age (Salthouse, 1996).”

“With adults, however, the simple cascade consistent with Salthouse (1996) was not found.”

“, 2000), which are directly linkable to the most frequent cognitive deficits observed in the human population (Gazzaley et al., 2005; Hasher et al., 1991; Salthouse, 1996).”

“…2000); indeed, some researchers have suggested that processing speed may compensate for deficits arising from other variables such as age, education and verbal ability, and that poor performance associated with age in memory training may actually be caused by slow processing (Salthouse, 1996).”

“One of the most dominant patterns in cognitive aging research is the approximately proportional Age X Complexity effect (e.g., Cerella, 1990; Salthouse, 1996).”

“Indeed, reduced speed of information processing has been consistently shown to be part of the normal aging process [54,55].”

“In fact, much research has been devoted to an understanding of factors that underlie cognitive slowing (for example, see Salthouse, 1996, for a review), although a detailed discussion of these factors is not within the scope of the present analysis.”

“Finally, a Letter Comparison test, Pattern Comparison test (e.g., Salthouse, 1996) and the Shipley Vocabulary test (Shipley, 1986) were also administered.”

“While reliance of higher order abilities on PS is complex (Park & Reuter-Lorenz, 2009), it has been hypothesized that reductions in PS may account for much of the age-related cognitive change in higher order abilities (Finkel, Reynolds, McArdle, Hamagami, & Pedersen, 2009; Salthouse, 1996, 2010).”

“…shown to be closely linked to other cognitive domains, such as executive functions (e.g. Chen and Li, 2007; Conway et al., 2003), processing speed (e.g. Burgaleta and Colom, 2008; Clay et al., 2009; Salthouse, 1996), and fluid intelligence (e.g. Ackerman et al., 2005; Kyllonen and Christal, 1990).”

“Such an outcome suggests that the speed of processing may interact with or partially underlie developmental differences in capacity, as has been argued by Kail (1991) and Perfetti (1985) in the literature on development during childhood and by Salthouse (1996) in the literature on cognitive aging.”

“Whereas child development is associated with gains in information-processing speed (e.g., Kail, 1991), cognitive aging is related to the general slowing of information processing (e.g., Salthouse, 1996).”

“include a slower processing speed [54], difficulty with both episodic and working memory, reduced ability to learn and retrieve both non-verbal and verbal material [55–58], decreased attention [59–61], and difficulty task switching [62–64].”

“It is well established in the literature that normal aging is associated with changes in cognition, including executive functions, such as declines in inhibitory control (Hasher and Zacks, 1988) and processing speed (Salthouse, 1996), as well as language comprehension (Kemper, 2006).”

“Nonetheless, our observation of an independent association between CWP and performance on the DSST is potentially important, as psychomotor speed underpins a number of higher-order cognitive tasks [45] and predicts neuropsychological decline in older adults [3].”

“OA scored lower than YA on a timed pattern comparison task (Salthouse, 1993). consistent with decreases in processing speed in older adulthood (Salthouse, 1996).”

“A further hypothesis—the processing speed hypothesis—proposes that cognitive performance in older subjects is degraded because cognitive processing is slower and the relevant operations cannot be successfully executed (Salthouse, 1996).”

“Salthouse postulated that these speed-related deficits limit the efficiency and accuracy of performing tasks across a range of cognitive domains (for a review, see Salthouse, 1996).”

“There is evidence that information processing efficiency in human cognition is influenced by the interaction between processing speed and its influence on the size and flexibility of the WM buffer [DeLuca et al., 2004a; Demaree et al., 1999; Salthouse, 1996b; Salthouse and Coon, 1993].”

“Life-span psychological research has long been interested in structural relations among intraindividual changes within and between domains of functioning (Baltes & Nesselroade, 1979; Brandtstädter & Lerner, 1999; Broidy et al., 2003; Dixon, 2005; Hertzog, Dixon, Hultsch, & MacDonald, 2003; Rutter, 1998; Salthouse, 199…”

“Another issue that was investigated in the present study was whether changes in working memory performance across the lifespan reflect changes in capacity size or in processing resources (Salthouse, 1996).”

“They experience deterioration in sensory and cognitive skills (c.f. Dunbar et al., 2004; Kovalchick et al., 2004; Salthouse, 1996), and a progressive loss of feeling independent (Orimo et al. 2006).”

“Performance in a complex task may be a non-linear function of basic system parameters (Salthouse, 1996).”

“The Processing Speed Theory states that declines in processing speed with increasing age can result in impairments in cognitive performance (Salthouse, 1996).”

“For a regional study of tissue oxygenation, sampled points were divided into three categories: (1) “near arterioles”, including the points within 100 μm from an arteriole; (2) “near venules”, including the points within 100 μm from a venule, but at least 100 μm from the closest arteriole, and (3) “capillary bed” inclu…”

“23 Older adults, mostly over 65 years, may experience changes in psychomotor functions that result in a slower response speed 24 and impaired motor coordination and dexterity.”