The processing-speed theory of adult age differences in cognition

“At the behavioral level, one of the most central age-related declines is a reduction of general cognitive speed (Fisk & Warr, 1996; Salthouse, 1996).”

“The general speed of information processing slows down in older adults (Salthouse, 1996), which may explain why cognitive factors are sometimes a better predictor of SUN than hearing acuity (Wingfield, 1996; Benichov et al., 2012).”

“A further compromise may occur due to age-related changes in cognitive processes (Bishop, Lu, & Yankner, 2010; Grady, 2012; Salthouse, 1996), additionally affecting perception of speech in adverse listening conditions in hearing-impaired (HI) individuals (Divenyi & Haupt, 1997; Dubno, Dirks, &…”

“The task-independence of this effect has inspired a highly influential hypothesis that cognitive aging can be understood in terms of a general slowing of information processing due to increased neural noise [5,28,29].”

“…would spend more time viewing selection pages fits with mainstream lifespan developmental theorizing, perhaps reflecting age differences in processing speed (Salthouse, 1996) or increased informational selectivity in older adults, in line with findings from SST (Löckenhoff & Carstensen, 2004).”

“Some have claimed that with age there is a decrease in the speed of processing information in the cognitive system (Salthouse, 1996).”

“Large amounts of age-related variance were present for each cognitive outcome measure, indicating as previously reported, that performance on the cognitive domains selected for the current study declines with increasing age (Anstey & Smith, 1999; Salthouse, 1996).”

“…has been found in a large number of brain disorders like Alzheimer's, Parkinson's or schizophrenia (Goldman-Rakic, 1994; Silver et al., 2003), but also during normal aging (Wingfield et al., 1988; Salthouse, 1996; Cabeza et al., 2004; Rajah and D'Esposito, 2005; Grady, 2008; Burgmans et al., 2010).”

“With advancing age, the speed with which many mental operations are executed decreases, and this is considered to be the main mechanism accounting for the age-related decline in most cognitive tasks (Salthouse, 1996).”

“Hypertension is also linked to reduced performance in multiple age-sensitive areas of cognition: speed of perceptual-motor processing (Salthouse, 1996b), episodic memory (Brady, Spiro, & Gaziano, 2005; Harrington, Saxby, McKeith, Wesnes, & Ford, 2000; Singhmanoux & Marmot, 2005), and executive…”

“Yet, the advantage of focusing on fluid cognitive abilities is that they are considered the more basic cognitive dimensions that underly changes in higher-order cognitive performance such as that required for everyday memory tasks (Hertzog , Dixon, Hultsch, & MacDonald, 2003; Salthouse, 1996).”

“fundamental component of cognitive aging, which shares age-related variance with a wide variety of cognitive measures (Salthouse 1996; Madden 2001; Salthouse and Madden 2007).”

“The processing speed theory suggests that older adults experience significant cognitive slowing (Salthouse 1996).”

“... white matter changes are associated with attenuated performance on tasks of processing speed, immediate and delayed memory, executive functions, and indices of global cognitive functioning (Gunning-Dixon & Raz, 2000), and neuropsychological studies demonstrating large attenuation of age-related influences on cogni…”

“numerous empirical investigations that support this view (see Salthouse, 1996 ).”

“Information processing capacity and speed concerns the domain of cognitive functioning that has been documented to be most strongly affected by aging [27].”

“The phenomenon of cognitive slowing has been used to explain the neuropsychology of aging (Salthouse 1996).”

“irrelevant information (Hasher, Zacks, & May, 1999), while other processes such as executive control (Hay & Jacoby, 1999) and generalized slowing (Salthouse, 1996) are also believed to be significant.”

“First, ageing is associated with declines in the efficiency of controlled processing mechanisms, such as working memory (MacPherson, Phillips, & Della Sala, 2002; Salthouse, 1994), processing speed (Salthouse, 1996), and inhibition of task-irrelevant information (Hasher & Zacks, 1979).”

“We also attribute this effect to individual differences in domain-general intelligence (Bates & Stough, 1997; Bickley, Keith, & Wolfle, 1995; Der & Deary, 2003; Martin, 2001; Salthouse, 1996).”

“In contrast to the potential benefits of increased language exposure as one ages, there are a number of well-documented domains that show age-related breakdowns, including processing speed (Salthouse, 1996), lower level sensory abilities (Fozard & GordonSalant, 2001), and attentional control (Kramer & Kray, 2006).”

“This is consistent with aging theories proposing general slowing of cognitive operations (29), as well as theories invoking cognitive control deficits impacting the ability to update task relevant context (30).”

“Such processing resource accounts posit that age associations across many cognitive tasks are not independent, but rather reflect the influence of relatively few general factors (Salthouse, 1991, 1996).”

“These results are in line with previous findings in the cognitive aging literature (Salthouse, 1996; Schmand et al., ; Stern, 2003; Van der Elst, 2006; Van der Elst et al., 2006d).”

“…functioning, memory, language and visuospatial function, as indicated by neurochemical theory, localized theory and process theory (Dempster, 1992; Salthouse, 1996; West, 1996; Volkow et al., 1998; Bäckman et al., 2006; Clay et al., 2009; Drag and Bieliauskas, 2010; Craik and Rose, 2012;…”

“Among the candidates are reduced cognitive resources such as speed of processing (Salthouse, 1996), impaired attentional control (Craik & Byrd, 1982; Kim & Giovanello, 2011), weakening of executive control (Moscovitch & Winocur, 1992; West, 1996), and reduction in attentional resources (Anderson,…”

“Each word pair was presented during 3 s for the young and during 6 s for the older participants to control for age-related speed processing issues (Salthouse, 1996), which may lead to less efficient cognitive processing, including memory encoding (Davis et al., 2003; Craik and Rose, 2012).”

“To obtain an RT measure that reflected general processing speed, known to decrease with age (Salthouse, 1996), as opposed to their speed of memory retrieval, an average was taken of RT for all conditions in the subsequent memory test, for both correct and incorrect responses, for which observations…”

“stimulus presentation too challenging, likely due to the age-related decline in speed of information processing (e.g., Salthouse, 1996 ).”

“…in speed of processing ability ( Hertzog, Dixon, Hultsch, & MacDonald, 2003 ; Levitt, Fugelsang, & Crossley, 2006 ; Luszcz, Bryan, & Kent, 1997 ; Salthouse, 1991 , 1996 ), potentially explaining why when both reasoning ability and speed of processing ability were included in the adjusted model,…”

“General slowing of cognitive operations has been offered as one theory to describe past attentional deficits during aging (Cerella, 1991; Hale, Myerson & Wagstaff, 1987; Salthouse, 1996).”

“However, age differences in speed were not more pronounced in the complex dual task set that was presumably more cognitively demanding, a finding not in support of the ProcessingSpeed Theory [18], although age differences in accuracy emerged.”

“Indeed, deficits in some form of processing speed may underlie many age-related cognitive declines Salthouse, 1996 .”

“These properties, together with evidence that processing speed is integral to higher-order processes such as reasoning [43], may be a key indicator of changes in neural efficiency [44] and functional outcomes [45], and is an important mediator of age-related cognitive changes [46], make speed tasks ideal as outcome me…”

“…2002, 2006; Richter, Dietzel, & Kunzmann, 2011), especially executive function (Apperly, Samson, & Humphreys, 2009; Circelli, Clark, & Cronin-Golomb, 2013; Pardini & Nichelli, 2009; Suzuki & Akiyama, 2013; Ze et al., 2014), which showed uniform decline with age (Salthouse, 1996; West, 1996).”

“Thus, processing steps have to be repeated (Salthouse, 1996).”

“Both the hypothesised overall decline in computational resources (Craik, 1986) and reduction in processing speed (Salthouse, 1996) AC CE PT ED M AN US CR IP T”

“For example, age-related changes in processing speed have been strongly implicated in age-related changes in working memory (e.g., Fry & Hale, 1996; Kail & Salthouse, 1994; Salthouse, 1996).”

“A major contributing factor to age-related decline in episodic and working memory appears to be a slowing of information processing that applies across a wide range of component abilities (Madden, 2001; Salthouse, 1996).”

“Baddeley, Thomson, and Buchanan (1975) noted that the accuracy of recall depended on the number of items that an individual could recite in about 2 sec, and subsequent work indicated that the recitation rate slowed with aging (Kynette, Kemper, Norman, & Cheung, 1990), in keeping with a cognitive-slowing theory of agin…”

“…& Diehl, 2000) dynamic integration model, which suggests that, because of age-related declines in cognitive control and other resources (e.g., Salthouse, 1996; Craik & Bialystok, 2006), older adults often reduce the cognitive, and possibly allostatic, loads associated with performing…”

“The PS theory of aging suggests that PS is the leading redictor of changes in cognitive abilities, especially in fluid abilities Salthouse, 1996 ).”

“C O G N O R M A T IV E D A T A 4 0 1 been demonstrated on cognitive functioning: slowdown in processing speed (Salthouse, 1996), declines in inhibitory processing (Radvansky, Zacks, & Hasher, 2005), decrease in performance related to working memory (De Beni & Palladino, 2004) and episodic memory…”

“This concept, known as the unspecific hypothesis of general slowing with increasing age, is not limited to inhibitory processes but is thought to apply to all cognitive processes [Salthouse, 1996].”

“In recent years, cognitive ageing researchers have invoked several hypotheses to explain age-related memory loss, namely the processing resource hypothesis ( Salthouse, 1996 ), the executive function hypothesis ( Dempster, 1992 ) and the common cause hypothesis ( Lindenberger & Baltes, 1994 ).”

“Age-related differences in certain tasks may be related to a general slowing of the aging cognitive and perceptual systems (Salthouse, 1996).”

“Use of external cues may be a compensatory mechanism supporting older adults’ information processing in the face of age-related general slowing (e.g., Salthouse, 1996) and noisy internal representation systems (Spieler et al., 2006).”

“A decline in processing speed also impacts on the accuracy of task completion under limited time constraints, resulting in a trade off for speed rather than accuracy (Salthouse, 1996).”

“Circulating blood Pb could affect synaptic transmission and plasticity and thereby impede, for example, information storage mechanisms or processing speed, which has been suggested to weaken performance on cognitive tests.(54) In future studies, more incisive measurements offered by imaging technology (eg, structural…”

“While it is likely that general slowing in processing of information is the key cause of delayed motor responses (Salthouse, 1996), other cognitive functions (e.”

“One of the universal findings in cognitive aging research is reduced speed of information (sensory and mental) processing with advancing age.(9) This reduction in the speed of information processing along with reduction in cognitive skills is known to effect listening comprehension.”

“…function that likely contributes to sentence recognition under degraded listening conditions is information-processing speed, which is related to performance on complex cognitive tasks such as reasoning and language comprehension (Salthouse, 1996; Verhaeghen & Salthouse, 1997; Wingfield, 1996).”

“According to this hypothesis, the ASRT task should reveal an age-related decline in implicit learning across the life span, because slowing is known to occur throughout adulthood (Salthouse, 1996).”

“These findings have led to the hypothesis that possibly one or very few factors may account for age differences in many cognitive abilities ( Salthouse, 1994 ).”

“A ‘simultaneity mechanism’ has been described as central to the processing speed theory of differences among adults in cognition (Salthouse 1996).”

“Some authors have stated that reduced processing speed is the most accurate explanation for the observed variation in performance of many different tasks in the elderly (Salthouse, 1996).”

“Overall, those findings can be considered as possible evidence of the protective role of certain proxies of CR, such as education, against the documented cognitive slowing naturally occurring with aging, ensuring better performances [109, 110].”

“Several theories of cognitive aging help explain these changes, including the Speed of Processing Theory (Salthouse, 1996), which posits that slower mental processing speed underlies broader performance declines; the Limited Resources Theory (Craik and Byrd, 1982) suggests a reduction in available…”

“IE is less influenced by generalized slowing (Salthouse, 1996), mood disorders (Borkowska & Rybakowski, 2001; Moritz et al.”

“Finally, the observed reduced speed of processing was also a classical effect of normal aging (Birren & Botwinick, 1955; Houx, Jolles, & Vreeling, 1993; Salthouse, 1996).”

“The decline of basic cognitive as well as higher order mental abilities like processing speed (Salthouse, 1996), switching (Cepeda, Kramer, & Gonzales de Sather, 2001), memory (Lindenberger & Baltes, 1997), inhibition (Williams, Ponesse, Schachar, Logan, & Tannock, 1999), reasoning (Zimprich et…”

“Salthouse (1996) has suggested that complex processes require temporal coordination and that if some components are delayed, the cognitive act (like a skilled motor act) will become clumsy and inefficient.”

“…changes in lower-level abilities (i.e. perceptual speed, psychomotor abilities) are proposed to account for the reduced performance in other abilities such as memory and executive functioning (Baltes and Lindenberger, 1997; Lee, et al., 2012; Park and Reuter-Lorenz, 2009; Salthouse, 1996).”

“number of cognitive tasks, including memory, reasoning, and spatial tasks (Kail and Salthouse 1994; Salthouse 1996).”

“It is now generally acknowledged that there are differences in both the extent to which particular processes are slowed and in the extent to which overall performance is slowed across tasks (e.g., Salthouse, 1996 ); researchers, however, differ substantially in what quantitative functions they believe best describe th…”