The processing-speed theory of adult age differences in cognition

“Used to assess processing speed, the letter comparison measure was a paper-pencil based cognitive task that required participants to determine whether two strings of letters were the same or different (Salthouse, 1996).”

“…from several studies show that response times from elementary cognitive tasks substantially mediate the relation of age and cognitive abilities (Finkel et al. 2007; Salthouse 1996), suggesting that age differences in intelligence might be (partly) based on age differences in processing speed.”

“The mLC is a modified version of the Letter Comparison task (Salthouse 1996).”

“the bases of cognition (Salthouse, 1996), slow processing speed might partially account for”

“cess and decode is thought to decline with age [33] [34].”

“Participants completed a cognitive battery consisting of the Shipley Vocabulary Test (Shipley, 1940), the Operation Span Task (Unsworth, Heitz, Schrock, & Engle, 2005), Trail-Making Test Part B (Wechsler, 1997), and the Digit Symbol Substitution Task (DSST; Salthouse, 1996).”

“Jensen's (2006) suggestion that RTmay index some fundamental characteristic of the brain that reflects the efficiency of complex cognitive systems of information processing is plausible, particularly in relation to cognitive changes associated with normal ageing (Salthouse, 1996).”

“For instance, Kail and Salthouse ( 1994 ) and Salthouse ( 1996 ) postulated processing speed as the general mental resource that subserves a large array of higher-order cognitive functions.”

“Generalized slowing is one possible explanation for this finding (Byrne, 1998; Salthouse, 1996).”

“…some argue that global processing speed reductions explain a majority of cognitive impairment, while others attribute agingrelated impairments to declines in prefrontal function and brain network connectivity (Greenwood, 2000; Nordahl et al., 2006; Salthouse, 1996; Salthouse, 2000; West, 1996).”

“This is in agreement with previous studies (Clark, Chamberlain, & Sahakian, 2009 ) and supports the theory that normal aging corresponds mainly to a decline in executive functions (Salthouse, 1996 ), in addition to long-term declarative memory.”

“Additionally, changes in processing speed have been welldocumented in the aged (Salthouse, 1996; Carp et al., 2010), and Frontiers in Aging Neuroscience www.frontiersin.org September 2012 | Volume 4 | Article 10 | 2 need to be accounted for in studies that examine the precise reaction time of an…”

“Several competing candidates may play this role of mediator: executive functioning (West, 1996), especially inhibition (Hasher & Zacks, 1988), or processing speed (Salthouse, 1996).”

“…in schizophrenia (Gur et al., 2007; Silver et al., 2003; Nuechterlein et al., 1992; Wohlberg and Kornetsky, 1973; Asarnow and MacCrimmon, 1978; Salthouse, 1996; Goldman-Rakic, 2001; Conklin et al., 2005; Ando et al., 2001; Hansell et al., 2005; Tuulio-Henriksson et al., 2003; Saperstein et…”

“Reaction time scores become markedly slower with age ( Salthouse, 1996 ), leading some researchers to suggest that they are good markers of cognitive aging ( Deary, Johnson, & Starr, 2010 ), although slowing of processing speed does not fully explain cognitive decline ( Zimprich, 2002 ).”

“A related suggestion is that older adults may exhibit lower processing speed (e.g., Salthouse, 1996).”

“Alternatively, it is possible that aging results in a global cognitive decline (e.g. Craik & Byrd, 1982; Benjamin, 2008; Hasher & Zacks, 1979), such as a decline in processing speed (Salthouse, 1996).”

“The decrease of processing speed with older age has been well documented [53,54].”

“ERP analyses suggested that this increase in RTs was associated with a delayed capture of attention and a delayed re-focusing of attention after a change in target location, in accordance with the general slowing hypothesis (Salthouse, 1996).”

“General processing speed is also critical for utilizing many other cognitive skills effectively, and as such improvement in this area is important (Dang et al., 2015; Poll et al., 2013; Salthouse, 1996).”

“Declines in general cognitive processing speed have been considered a hallmark of the aging process, beginning in young adulthood and continuing nearly linearly across the lifespan [58].”

“Theories of cognitive ageing, which view age-related deficits in terms of a generalised slowing of cognitive processes (e.g., Salthouse, 1996), would predict the slower performance of the old-old participants.”

“single mechanism such as a decrease in information processing speed (3).”

“In fMRI studies utilizing the n-back paradigm, aberrant activation patterns in the prefrontal cortex (PFC) are correlated with cognitive decline in elderly individuals (Salthouse, 1996; Owen et al., 2005).”

“Second, normal aging is associated with neurocognitive slowing (Salthouse, 1996), with EEG and MEG studies showing processing delays for multiple neural components (Onofrj et al., 2001; Zanto et al., 2010; Clarke et al., 2015).”

“Such age-dependent and therefore characteristic delays have often been described in the memory literature (Salthouse, 1996; Park et al., 2002; Luo and Craik, 2008).”

“According to Salthouse (1996), time to successfully process the incoming (speech) information is limited, while also other mechanisms are taking place simultaneously (e.g., suppression of noise, generation of verbal response).”

“Finally, older adults typically experience a general slowing of perceptual processing speed which could account for age-related declines in some visual tasks (Costello et al., 2010; Salthouse, 1996).”

“…speed and thus statistically control for the task impurity arising from the multidimensionality of each individual test considered alone (see Salthouse, 1996, 2000, for a discussion of processing speed indicators in factor analysis and see also Miyake et al., 2000, for a similar discussion…”

“, the general slowing hypothesis) has been addressed for a long time in cognitive literature (47, 48).”

“As people age, processing speed decreases, as indicated by measures such as slower reaction times (Salthouse, 1996), possibly due to noisy brain processing arising from degraded sensory inputs (Mahncke, Bronstone, & Merzenich, 2006).”

“One possible cause for individual differences in processing speed is global slowing with aging (Myerson, Hale, Wagstaff, Poon, & Smith, 1990; Salthouse, 1996; Schneider, Pichora-Fuller, & Daneman, 2010).”

“Beyond LRS and WM, it has also been reported that verbal fluency is associated with processing speed (PS), which refers to the ability to rapidly execute simple cognitive tasks (Bryan et al., 1997; Camarata & Woodcock, 2006; Hedden et al., 2005; Salthouse, 1996); inhibition, the ability to suppress irrelevant informat…”

“…tasks related to language production and comprehension (see Ratcliff, Thapar, Gomez, & McKoon, 2004; Rayner, Reichle, Stroud, Williams, & Pollatsek, 2006; Salthouse, 1996) and lower reading speed (see Kemper & Liu, 2007; Rayner et al., 2006; Solan, Feldman, & Tujak, 1995; Whitford & Titone, 2017).”

“…were instructed to decide as quickly as possible whether the two letter strings were the same or different by pressing but-tons on a response button box labeled “ same ” or “ different ” (see Earles & Salthouse, 1995; Salthouse, 1996 for a paper-and-pencil version of this task as a speed measure).”

“At the same time, there appears to be an agreement that tasks involving lexical knowledge remains fairly unaffected by aging in comparison to tasks recruiting online processes [53, 84, 85].”

“In addition to cognitive flexibility, the TMT-B test may also capture processing speed, which could also play an important role in cognition for older adults (Salthouse, 1996).”

“Other studies of normal aging point to similar age effects on information processing with a normal slowing of various speed variables, such as reaction time and perceptual, psychomotor, and psychophysical speed (Salthouse, 1985, 1996, 2000, 2004; Verhaegen & Salthouse, 1997; Perry & Hodges, 1999).”

“For example, different cognitive resources like processing speed ( Salthouse, 1996 ) or working memory ( Salthouse, 1990 ) have been established as predictors of change in memory performance, which conceptually resembles initial performance (eg, Hultsch et al, 1998 ; Lemke & Zimprich, 2005 ).”

“First, aging is associated with reduced cognitive speed (e.g., Salthouse, 1996).”

“* This follows from the fact that the information-processing paradigms employed are generally assumed to be representative of the more global construct of cognitive (or mental) speed (e.g., Hale & Jansen, 1994; Neubauer & Bucik, 1996; Salthouse, 1996).”

“As individuals age, processing speed begins to decline along with several other cognitive abilities, including working memory (Schaie & Zanjani, 2006; Salthouse, 1996).”

“There is a speed view which posits that older participants recruit more cognitive resources to compensate for age-related reductions in processing speed (e.g., Salthouse, 1996; Schaie, 1994; see also Cabeza, 2002; Reuter-Lorenz & Cappell, 2008; Stern et al., 2003).”

“…M anuscript A uthor M anuscript A uthor M anuscript A uthor M anuscript speed of processing is that it is a major determinant of ST-WM capacity (Salthouse, 1996), and any effect of ST-WM on a function may be largely or entirely due to speed of processing, not the memory abilities measured in…”

“…que siguen apelando a limitaciones de capacidad general –y no de procesamiento específico– como fuente de las restricciones en la ejecución, y como factor responsable de las diferencias evolutivas, particularmente entre ancianos y adultos (Foos y Wright, 1992; Salthouse, 1990, 1996; Swanson, 1999).”

“…tales como un enlentecimiento en el procesamiento de la información (Brigman & Cherry, 2002; Myerson, Hale, Swagstaff, Poon, & Smith, 1990; Salthouse, 1996), una alteración de ciertos componentes atencionales tales como la capacidad atencional, la red de alerta, y, muy especialmente, de…”

“Processing speed refers to processing efficiency or rate (Kail & Salthouse, 1994; Salthouse, 1996) and emphasizes the amount of cognitive work that can be done in a given unit of time.”

“…timed EF tasks in our AD group, it seems plausible to surmise that slowed processing speed may partially account for the AD-related deterioration in certain EF tasks in a similar fashion as that seen in age-related cognitive changes in normal aging (Salthouse, 1996), which awaits further research.”

“The known information processing speed decrease with physiological aging [6, 7] may underlie the marked [8] increase in the time required by elderly subjects to generate large number of solutions of a divergent problem.”

“По мере того, как человек становится старше, процесс восприятия новой информации и ее кодирования для последующего хранения требует все большего времени, что связано со сниженной эффективностью нервной передачи и сенсорным дефицитом, который ограничивает способность человека быстро и точно воспринимать информацию, пре…”

“age, then, can be an important factor, since aging results in an overall decline or slowing down of the cognitive system (Salthouse, 1996).”

“In addition, processing speed (Gs) might be relevant for the efficiency of the visual inspection task (Salthouse, 1996).”

“Finally, in line with the decline in processing speed hypothesis in older people (Salthouse, 1996), older adults presented a more delayed P3 latency than young adults, reflecting a slower feedback evaluation process (Porcaro et al., 2019).”

“The presence of a generalized slowing of responses in older adults supports the ProcessingSpeed Theory of cognitive aging [20].”

“The present findings, in concert with those reported in reference to group means comparisons, may provide impetus to develop process models of the nature and impact of visual memory and processing speed deficits in schizophrenia (cf. Salthouse, 1996).”

“Relatedly, cognitive aging involves slowing of processing speed (Salthouse, 1996), which has been found to be associated with decreases in myelination in older adults (Bartzokis, 2004).”

“For example, there are significant declines in verbal memory, spatial ability and verbal memory attributed to a reduction in processing speed [10].”

“, 2006) – both potentially in addition to, or interacting with, age-related declines in processing capacity (Jones et al., 2006; Salthouse, 1996).”