The processing-speed theory of adult age differences in cognition

“…of Aging 29 (2008) 329–340 Accelerated age-related cortical thinning in healthy carriers of apolipoprotein E 4 Thomas Espeseth a,∗, Lars T. Westlye a, Anders M. Fjell a, Kristine B. Walhovd a, Helge Rootwelt b, Ivar Reinvang a a Department of Psychology, University of Oslo, P.O. Box 1094,…”

“Gray matter volumes have been shown to decline in humans beginning in adolescence and continue to decline linearly throughout the life span [14,41,66,69].”

“Among the changes most commonly associated with normal aging are slowing in reaction times and the overall speed of information processing (Salthouse, 1996; Sliwinski & Buschke, 1999) and reduction in visuospatial and motor control abilities.”

“This age-related slowing is consistent throughout the study and is presumably due to generalized slowing (Salthouse, 1996).”

“Theories and explanations for the effect of aging on dual-task costs in cognitive paradigms include decline in speed of processing (Salthouse 1996; Somberg and Salthouse 1982) response selection bottleneck (Hartley 2001; Hartley and Little 1999) and reduced executive supervisory control and…”

“, 2005) in several functions, including processing speed (Salthouse, 1996), peripheral vision (Muiños and Ballesteros, 2014), dynamic visual acuity (Muiños and Ballesteros, 2015), working memory (WM), executive control functioning, and episodic memory (e.”

“…of processing speed and working memory, because both are related to psychometric intelligence (Ackerman, Beier, & Boyle, 2002, 2005; Colom, Abad, Rebollo, & Shih, 2005; Colom, Rebollo, Abad, & Shih, 2006; Colom, Rebollo, Palacios, Juan-Espinosa, & Kyllonen, 2004; Fry & Hale, 1996; Salthouse, 1996).”

“These age-related changes in processing speed are thought to mediate, at least partially, age-related changes in other aspects of cognition, including verbal ability, spatial ability, and reasoning (see Kail, 1991; Salthouse, 1996).”

“…between working memory span and higher-order cognitive activities such as reading comprehension (Baddeley, 2000; McNamara & Scott, 2001; Salthouse, 1996), but only when identical strategies are afforded by both the memory and cognitive ability tasks (Bailey, Dunlosky, & Kane, 2008;…”

“003 speed [13], a reduced efficiency of inhibitory control (mechanisms preventing non-relevant information from interfering with current task) and a decrease in performance related to working memory (responsible for temporary maintenance and manipulation of information when carrying out complex cognitive tasks) [14] a…”

“This additional recruitment results in slowing and the common finding that dynamic aspects of cognition are more impacted by age than more static functions (Salthouse, 1996).”

“Salthouse (1996) suggests that tasks requiring effective encoding and retrieval rely on intact working memory and processing speed, so problems with these domains may have had detrimental effects on learning and recall exercises.”

“For example, Salthouse’s [58] processing-speed theory assumes the quality or quantity of information decreases as processing speed slows.”

“This may explain why working memory and processing speed measures share a large part of their age-related variance (Salthouse, 1996).”

“The assumption of a slowing of an internal timing mechanism has also been proposed (Schroots and Birren 1990, Surwillo 1968) to account for the slower information processing found in older adults on perceptual and motor tasks (Cerella 1990, Salthouse 1994, 1996, Wearden et al. 1997).”

“Theoretical views have emphasized agerelated declines in speed of mental processing (e.g., Park et al., 1996; Salthouse, 1996), decreases in general resources necessary for effortful processing (e.g., Craik, 1986; Craik and Rose, 2012), the inability to bind new associations among elements of an…”

“An age-related delay in an electrophysiological correlate of a resource-demanding operation such as episodic retrieval is perhaps unsurprising, given the extensive evidence that such operations are, in general, slowed in older subjects (Salthouse, 1996).”

“One group argued that processing speed is the primitive that predicts cognitive task performance and can be delineated by age differences (Salthouse, 1996; Salthouse & Babcock, 1991).”

“The relevance of this factor in attentional models has also been established in other neurological and psychiatric conditions, such as developmental attentional disorders, multiple sclerosis and schizophrenia [28, 41, 60, 61].”

“They depend on the ability to apply mental processes to situations requiring no previous knowledge, thus necessitating more conscious and effortful processing (Christensen et al., 1999; Salthouse, 1996 ).”

“Basic information processing speed is defined as the (mental) speed with which elementary cognitive tasks are executed, commonly measured by reaction time tasks (Coyle, Pillow, Snyder, & Kochunov, 2011; Salthouse, 1996; Takeuchi et al., 2011).”

“In particular, agerelated decline has been reported for the speed of information processing (Salthouse, 1985, 1996), deficits in the division of attention (McDowd and Shaw, 2000), dual-task performance (Hawkins et al., 1992), and in sensory and motor functions (Park, 2000).”

“Further, multisensory interactions were significantly greater in old relative to young adults, even after adjusting for age-related differences in speed of processing (Salthouse, 1985, 1996, 2000).”

“The noisy association 0 0.2 0.4 0.6 0.8 1 Recall Probability Weak Associations YD OD OM Noisy Associations Weak & Noisy 0 0.2 0.4 0.6 0.8 1 Recall Probability Drift Rate List Isolation Retrieval Editing 1 5 10 0 0.2 0.4 0.6 0.8 1 Serial Position Recall Probability Slowed Encoding 1 5 10 Serial Position Slowed Retrieva…”

“Also, these age differences were not simply a byproduct of general slowing (Salthouse, 1996).”

“…approach is to use hierarchical regression analyses in which the age-related variance in performance on incongruent trials is examined after statistically controlling for performance on neutral trials or alternative measures of processing speed (cf. Salthouse, 2001; also see Salthouse, 1996).”

“Prior research (see Bialystok & Craik, 2006, for a review) has suggested that modality-general, age-related memory decline may be due to mounting deficits in mental processing speed (e.g., Salthouse, 1996), attention resources (e.g., Craik, 1986), and cognitive control (e.g., Zacks & Hasher, 1994).”

“According to some authors (e.g., Salthouse, 1996), these failures result from a general slowing on all cognitive tasks in the elderly, including language; others argue instead for a more language-specific explanation, attributing the decline in naming performance to a weakening of connections…”

“Decrease in processing speed has been found to be associated with aging (46,47).”

“Since VZ is related to speed of processing spatial information (Salthouse, 1996), this might have affected speed of encoding information in the display, such that only participants with high VZ were able to keep up with the pace of the animation.”

“Especially in elderly subjects, processing capacities are said to decline ~ e.g., Gordon-Salant and Fitzgibbons, 1997; Salthouse, 1996 !”

“Measures of fluid processing abilities, such as speed of processing and executive function, tend to decline with age compared with measures of crystallized knowledge (e.g., vocabulary, world knowledge) (Salthouse, 1996; Park et al., 2002).”

“Thus, it is not surprising that they play a role in a large number of tasks (Kirasic et al., 1996; Salthouse, 1996).”

“Generalized slowing has been hypothesized to account for aging effects across domains including language comprehension (Salthouse, 1996, 2000).”

“Cognitive accounts have attributed the observed age-related WM changes to a general slowing of cognitive processing (Salthouse, 1996), to declines in attentional resources (Craik & Byrd, 1982), to reduced efficiency of inhibitory processes (Hasher & Zacks, 1988; Rypma & D’Esposito, 2000), or to…”

“These groups include children, older adults, poor readers, and young adults who score less well on intelligence tests (see, e.g., Casey, Giedd, & Thomas, 2000; Dempster & Corkill, 1999; Engle, Tuholski, Laughlin, & Conway, 1999; Fry & Hale, 1996; Gernsbacher & Faust, 1991; Hasher & Zacks, 1988; Kail, 1993; Salthouse,…”

“However, one must note that response slowing might also rely on slowing speed of processing with age (Charlton et al., 2008; Park et al., 2002; Salthouse, 1996).”

“For example, there is evidence that older people perform more slowly than younger ones in many types of tasks (Salthouse, 1996), and they have fewer processing resources available (Salthouse, 1991).”

“Identifying factors associated with agerelated decrease in processing speed is important, given that slowed processing speed has been implicated as the broad underlying deficit for other age-related cognitive declines (Salthouse, 1996).”

“In his processing speed theory of adult age, Salthouse (1996) described processing speed as being a sort of mental “bottle neck” for successfully performing many cognitive tasks.”

“Cognitive theories of aging point to declines in biologically based cognitive functioning, such as the general slowing hypothesis (Salthouse, 1996) and the inhibitory deficit hypothesis (Hasher and Zacks, 1988).”

“A dominant metaphor for this research has involved processing resources that are available for encoding, retaining, and retrieving to-be-remembered information (e.g., Craik & Byrd, 1982; Hultsch et al., 1998; Light, 1996; Salthouse, 1996).”

“The behavioral consequences of these changes can include declines in working memory resources as well as slowing in a variety of perceptual and cognitive tasks (Kausler, 1991; Salthouse, 1996).”

“These findings are consistent with previous studies that have documented a steady decline in fluid cognitive functions with increased age (Park, 2000; Schaie, 2005) and specifically in processing speed (Salthouse, 1996) and short-term memory (Verhaeghen et al., 1993).”

“…an individualdifference approach, researchers have demonstrated systematic declines across the life span for a variety of tasks including those reflecting information-processing speed (e.g., Nettelbeck & Rabbitt, 1992; Salthouse, 1996) and working memory (e.g., Dobbs & Rule, 1989; Salthouse, 1994).”

“The processing speed hypothesis of aging (Salthouse, 1996), however, posits that causality points from processing speed to other cognitive abilities.”

“Participants were given a modified version of the Educational Testing Service Advanced Vocabulary Test—V-4 (Ekstrom, French, Harman, & Dermen, 1976; see Hertzog, 1989); the Computation Span Test (Salthouse & Babcock, 1991), a measure of working memory span; and the Letter Comparison and Pattern Comparison Tests (Salth…”

“Motor performance increased from childhood (7–9) to young adulthood (19–25) and decreased from young adulthood (19–25) to old age (66–80), mirroring the results from cognitive studies [6,38].”

“…stores that appear to be relatively immune to age-related deterioration and while they are generally considered to comprehend well, there is often a decline in their ability to operate in a timely manner on such structures (e.g., Myerson, Hale, Poon, Wagstaff, & Smith, 1990; Salthouse, 1996).”

“Some of these declining fluid abilities are processing speed, episodic memory, reasoning, and executive functions (Cerella, 1990; Park et al., 2002; Salthouse, 1996; Verhaeghen, 2011).”

“Some theorists (e.g., Jensen, 1998; Salthouse, 1996) proposed that mental speed determines storage capacity, because representations in WM quickly decay, and the faster these representations can be processed before falling below a retrieval threshold, the more of them can be recalled, bound, or…”

“This issue is important theoretically and could be linked with processing-speed theory of adult age differences (Salthouse, 1996), one of the major contemporary theories of healthy aging.”

“Increasing age is consistently associated with cognitive decline (Salthouse, 1996; Salthouse et al., 1998), and there is evidence to suggest that age may moderate the impact of pain on cognitive performance in human and animal models (Leite-Almeida et al., 2009; Oosterman et al., 2013).”

“Optimal contiguity of visual and auditory information will minimise the probability of simultaneity problems (Salthouse, 1996).”

“Such changes could also contribute to older adults’ difficulties in processing auditory information by generally slowing down perceptual and cognitive operations (Salthouse, 1996) or by interfering with inhibitory control mechanisms (Hasher & Zacks, 1988).”

“A box completion task (Salthouse, 1996) was used to assess processing speed.”

“The processing speed theory posits a stronger relationship between processing speed and measures of fluid ability and working memory than with measures of crystallized ability ( Salthouse, 1996; but see Ghisletta and Lindenberger, 2003).”

“Outcomes: decision making, habits, and brand choice”

“For example, speed of processing is a variable that seems to decline in old age (Salthouse, 1996) as well as to be impaired by traumatic brain injury (Madigan, DeLuca, Diamone, Tramontano, & Averill, 2000) and are also thought to be related to prospective memory performance (West & Craik, 2001).”

“Because identification is a cognitive process and cognitive processes take time to develop (Salthouse, 1996), the process of identification can be viewed as time sensitive.”

“…that the age-related slowing in CPS underlies declines in other higher order cognitive functions such as memory and executive functioning (Hedden et al., 2005; Levitt et al., 2006; Rabbitt et al., 2007; Salthouse, 1995, 1996; Salthouse, 2005; Salthouse & Coon, 1993; Salthouse & Ferrer-Caja, 2003).”

“These differences appear to be particularly large for tests that emphasize executive functioning, as well as speed of response and attention (Salthouse, 1996; West, 1996).”

“Thus, processing speed, memory capacity, and memory control all deteriorate in parallel in elderly individuals, which likely contributes to decreases in intellectual capacity (Salthouse, 1996).”