The processing-speed theory of adult age differences in cognition

“For example, data presented in Salthouse (1996) indicates that the scores on the two comparison tasks and the Digit-Symbol Substitution are highly correlated and share a substantial proportion (from .72 to .97) of age-related variance in performance.”

“This argument is based on two patterns of results: (1) Regression analyses have shown that a large part of the age-related variance in working memory capacity can be accounted for by measures of processing speed (e.g., Salthouse, 1996 ).”

“…concerning encoding strategies in older adults has suggested that this group is less able to “self-initiate” deep encoding strategies, but benefit when they are provided with such strategies (Salthouse and Babcock 1991; Salthouse 1996; Logan et al. 2002; Morcom et al. 2003; Craik and Rose 2012).”

“The ability of older adults to ignore irrelevant and complicated information, information processing speed, and cognitive resource capacity decrease (Balota et al., 2000; Kahneman, 1973; Salthouse, 1996).”

“Although previous studies have identified a number of cognitive mechanisms that may underlie sentence comprehension in older adults, such as general processing speed (Salthouse, 1996; Caplan, DeDe, Waters, & Michaud, 2011) and attention control (e.”

“Researchers investigating the causes of age-related differences in WM have proposed several views, including single mechanism views (such as processing speed declines, e.g., Salthouse, 1996 ) and multiple mechanism views (such as dynamic contextual control and output forgetting, e.g.”

“Taken together, such studies support the theory for improved working memory performance proposed by Salthouse, the “limited time mechanism” (Salthouse, 1996).”

“…of age-related cognitive alterations are the ‘‘processing speed hypothesis’’ in which a global decline in processing speed is assumed (¼general slowing; Salthouse, 1996), and the ‘‘inhibitory deficit hypothesis’’ which proposes an inability to control interference from task-irrelevant information…”

“…deterioration of several cognitive functions, including speed of processing, working (short-term) memory, and long-term memory (Salthouse, 1994; 1996; Grady and Craik, 2000; Satre et al. , 2006) involved in the generation of vivid/detailed mental images (Baddeley and Andrade, 2000; Scailquin,…”

“To be able to do so, ADAS should compensate almost-universal age effects, such as reduced perceptual and visual-motor speed (e.g., Lindenberger, Mayr, & Kliegl, 1993; Salthouse, 1996) and decreased divided-attention capacities (e.”

“, 2007), processing speed (Salthouse, 1996) and executive functions (Royall et al.”

“Nevertheless, differences in processing speed between younger and OAs are among the most pronounced and widely replicated effects in the domain of cognitive aging (Salthouse 1996; Salthouse & Madden 2008).”

“This finding is of relevance as the basic speed of perceptual processing constitutes a limiting factor on higher level cognitive abilities (Salthouse 1996) and ameliorating deficits in early perceptual processing in ageing may show advantages that cascade throughout the cognitive hierarchy (Mishra…”

“We used indices of these general dimen sions of element integrity in LBC1936 to 329 obtain between-sample cross-validated predictions o f aging-sensitive domains of cognitive 330 function in older adulthood (2,63,64).”

“From this literature [2], it could be inferred [7] that age-related cognitive decline [41, 42] can also explain age-related differences in adaptation rates.”

“A large proportion of this variation appears to be caused by general cognitive decline, such that, when one domain of cognitive ability starts to decline, others also tend to deteriorate, though there is also additional age-related decline in specific cognitive abilities (Salthouse, 1996; Salthouse and Czaja, 2000; Wi…”

“Salthouse (1996) similarly has emphasized this point within a statistical analysis of cognitive aging.”

“Both the Trail Making and Fluency tasks emphasize processing speed, which has been implicated in age-related cognitive decline (Salthouse, 1996; Salthouse & Friscoe, 1995).”

“…1989; Demaree et al., 1999; Mostofsky et al., 2003; Rao et al., 1989a,b), schizophrenia (Cohen et al., 1997; Saykin et al., 1991, 1994), dementia (Bradley et al., 1989; Colette et al., 1999; Morris and Baddeley, 1988), and normal aging (Salthouse, 1992, 1996; Salthouse and Coon, 1993).”

“It was also anticipated that older adults may not show characteristic agerelated slowing (e.g., Salthouse, 1996) in response to emotional cues.”

“However, coding task impairment, the largest effect size found for cognitive impairment in schizophrenia [22,41], has not until recently been the focus of sustained experimental investigation, despite of the very general constraint that this performance dimension represents for cognitive processing [69].”

“For older adults, who experience reduced processing efficiency and diminished working memory capacity ([36], [64], [38]), being asked to engage in the split attention, resource heavy MRC task (see Appendix S1), which does not allow externalisation, is likely to lessen the resources available for searching, retrieving,…”

“Age-related differences in cognition include the domains of memory, fluid ability, and processing speed [Salthouse, 1996, 2004].”

“executive functions (Salthouse, 1996; Verhaeghen & Cerella, 2002), as well as u-shaped curves found for structural brain measures such as white matter volume (Groves et al.”

“For comparison purposes we also included measures of perceptual speed, as performance on these measures is thought to reflect the general efficiency of the cognitive system, and has been offered as an explanation for age-related changes in complex cognition ( Salthouse, 1996 ).”

“In general, the elderly have a lower performance level on highly demanding working memory tasks as well as a decreased cognitive speed (Li et al, 2001; Wingfield & Tun, 2001; Salthouse, 1996; Birren & Fisher, 1995).”

“…experienced by the older group may be related to other factors than olivocochlear functioning, such as a deterioration in cognitive functioning, which includes reduced working memory capacity [Gordon-Salant and Fitzgibbons, 1997] and the slowing of auditory signal processing [Salthouse, 1996].”

“Consistent with these effects, age-related decline in cognitive performance (Salthouse, 1996) can also be ameliorated by factors that affect performance expectations, such as whether there is an instructional emphasis on memory (Rahhal, Hasher, & Colcombe, 2001).”

“Also, it is noteworthy that older adults were not significantly slower than the younger adults, unlike most studies of cognitive performance in the elderly (e.g., Salthouse, 1996).”

“Trends ( ps .06) were observed in the same direction for a vigilance measure from the continuous performance task and the digit symbol task, a commonly used measure of processing speed (Salthouse, 1996).”

“This suggests that the predictive power of working memory does not arise from strategy use (e.g., Baddeley, 2000; Dunlosky & Kane, in press; Salthouse, 1996), but rather that a range of strategies causes unsystematic variance in the relationships between working memory and higher-level cognition…”

“Instead, it appears that general cognitive slowing (Salthouse, 1996) and, as a consequence, the strategy to trade processing speed for accuracy resulted in less efficient, although similarly accurate holistic processing.”

“The slower rating responses of older adults suggest a general slowing that occurs with ageing (Salthouse, 1996).”

“Influential theories of cognitive aging have attributed decrements in performance with advancing age to a generalized decline in the speed at which information is processed (Salthouse, 1996, 2000).”

“Some researchers contend that processing speed and attention/working memory mediate general cognitive abilities, including fluid intelligence (Jaeggi, Buschkuehl, Jonides, & Perrig, 2008; Salthouse, 1996).”

“Such findings may be construed to support the notion of general slowing of information processing with advancing age (Salthouse, 1996, 2000).”

“…DeLosh, & Davis, 2004; Zook et al., 2006), whereas processing speed is an unspecific function known to affect on a range of cognitive domains (Salthouse, 1996, 2000), this further argues for an age-related deterioration in the core planning processes from mid-adulthood onward as evidenced…”

“This is not surprising, given that aging is associated with alterations in both pain sensitivity [15-17] and cognition [18, 19].”

“T hi s ar tic le is in te nd ed so le ly fo r th e pe rs on al us e of th e in di vi du al us er an d is no t to be di ss em in at ed br oa dl y. existence of both shared and unique age-related influences may help explain why speed measures are particularly sensitive to age (e.g., Salthouse, 1996).”

“It is possible that improvements in reaction time may be insufficient for transfer to higher-level functions and that improvements in other basic functions, such as processing speed, may be necessary for such a transfer to occur [11].”

“In theory, one would expect a relatively strong within task correlation, and a relatively strong negative correlation between the Box Crossing and the CMT scores because they are both connected to a processing speed factor (Salthouse 1996).”

“In fact, a wealth of literature has shown that processing speed often emerges as the primary limiting factor for most aspects of memory performance (Bryan & Luszcz, 1996; Salthouse, 1996; Salthouse & Babcock, 1991; Slivinski & Buschke, 1997).”

“Hypothetically, slowed processing impacts cognition because relevant mental operations cannot be successfully executed and/or because the outcome of earlier processing may no longer be available when subsequent processing is complete (Salthouse, 1996).”

“One of the major proponents of the importance of processing speed for higher cognitive abilities has been Salthouse (1996), who offered two reasons why speed should be so important.”

“Processing speed, if considered a cognitive resource, has been suggested to lie at the core of cognitive aging (Salthouse, 1996).”

“It is well known that healthy ageing reduces information processing speed (Cerella, 1985; Myerson, Hale, Wagstaff, Poon, & Smith, 1990; Salthouse, 1996) and results in performance declines in various cognitive functions, including working memory (Morris, Craik, & Gick, 1990; Verhaeghen & Salthouse,…”

“Declines in processing speed between age 70 and 82 were greater than those of the other domains which supports the theory that processing speed is the core issue responsible for deficits in performance on complex cognitive measures in ageing populations [71-73].”

“For instance, a general cognitive slowing accompanies normal aging (Salthouse, 1996), and may account for the slowed reaction times observed in the behavioral task for older adults.”

“Processing speed refers to the rate at which elementary cognitive operations are carried out (20).”

“…of reference stimuli defined as pure tones or silent intervals Fitzgibbons and Gordon-Salant, 1994; Bergeson et al., 2001; Grose et al., 2006 and longer gap detection thresholds for gaps inserted between tonal markers or noise bands He et al., 1999; Snell and Hu, 1999; Lister et al., 2002 .”

“Controlling for changes in speed attenuates all other cognitive performance differences between young and old groups [ 57 ].”

“Significant decreases in decision speed also represent a key feature in dementia [6,7] and cognitive aging [11,12].”

“…that are tested in this task comprise of scanning, matching, switching, and writing operations that are reflective of several higher cognitive functions like perception, encoding and retrieval processes, transformation of information stored in active memory and decision making (Salthouse, 1996).”

“Information processing speed, attentional processes and inhibition controls are gradually affected (Salthouse, 1996, 2004).”

“Another possibility is that differences in processing speed (Salthouse, 1996) between younger and older adults might have contributed to differences in their recall performance.”

“Motor speed was measured using the box completion task (Salthouse, 1996), sustained attention with the digit vigilance or the number cancellation task (Lewis and Kupke, 1977) and verbal fluency with the begin letters D, A and T (Spreen and Benton, 1977).”

“The typical example of the “information-universal theories,” which is the general slowing theory described by Salthouse (1996) justifying the inclusion of control low-level cognitive and perceptual tasks (NJ and CJ).”

“to age-related cognitive decline (Salthouse, 1996) and is characteristic of PD dementia (Emre, 2003; Burn & Yarnall, 2014).”

“…2017; Kemper, Herman, & Lian, 2003b; Kemper, Marquis, & Thompson, 2001; Mayr, 2001; Park, Lautenschlager, Hedden, Davidson, Smith, & Smith, 2002; Salthouse, 1996, 2010; Verhaeghen, 2011) and because older speakers can compensate for some production difficulties because of their expanded…”

“26 This category of functions has also been shown to be sensitive to videogames.”

“These include various cognitive control functions such as monitoring one’s own actions, inhibiting inadequate reactions and suppressing distraction, as well as controlling attention (Salthouse, 1996; Verhaeghen and Salthouse, 1997).”

“, 2017; Gazzaley, Cooney, Rissman, & D'Esposito, 2005; Levine, Svoboda, Hay, Winocur, & Moscovitch, 2002) and speed of processing (Borella et al., 2017; Salthouse, 1996).”