Impact of sensory acuity on auditory working memory span in young and older adults.

The impact of sensory acuity, processing speed, and working memory capacity on auditory working memory span (L-span) performance at 5 presentation levels was examined in 80 young adults (18–30 years of age) and 26 older adults (60–82 years of age). Lowering the presentation level of the L-span task had a greater detrimental effect on the older adults than on the younger ones. Furthermore, the relationship between sensory acuity and L-span performance varied as a function of age and presentation level. These results suggest that declining acuity plays an important explanatory role in age-related declines in cognitive abilities. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Sensory functioning and intelligence in old age: A strong connection.

Relations among age, sensory functioning (i.e., visual and auditory acuity), and intelligence were examined in a heterogeneous, age-stratified sample of old and very old individuals (N?=?156, M age?=?84.9 yrs, age range?=?70–203). Intelligence was assessed with 14 tests measuring 5 cognitive abilities (speed, reasoning, memory, knowledge, and fluency). Together, visual and auditory acuity accounted for 49.2% of the total and 93.1% of the age-related reliable variance in intelligence. The data were consistent with structural models in which age differences in intelligence, including speed, are completely mediated by differences in vision and hearing. Results suggest that sensory functioning is a strong late-life predictor of individual differences in intellectual functioning. Explanations are discussed, including the possibility that visual and sensory acuity are indicators of the physiological integrity of the aging brain (common cause hypothesis). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The strong connection between sensory and cognitive performance in old age: Not due to sensory acuity reductions operating during cognitive assessment.

Cognitive aging research has documented a strong increase in the covariation between sensory and cognitive functioning with advancing age. In part, this finding may reflect sensory acuity reductions operating during cognitive assessment. To examine this possibility, the authors administered cognitive tasks used in prior studies (e.g., Lindenberger & Baltes, 1994) to middle-aged adults under age-simulation conditions of reduced visual acuity, auditory acuity, or both. Visual acuity was lowered through partial occlusion filters, and auditory acuity through headphone-shaped noise protectors. Acuity manipulations reduced visual acuity and auditory acuity in the speech range to values reaching or approximating old-age acuity levels, respectively, but did not lower cognitive performance relative to control conditions. Results speak against assessment-related sensory acuity accounts of the age-related increase in the connection between sensory and cognitive functioning and underscore the need to explore alternative explanations, including a focus on general aspects of brain aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The "common cause hypothesis" of cognitive aging: Evidence for not only a common factor but also specific associations of age with vision and grip strength in a cross-sectional analysis.

A prominent hypothesis in cognitive aging is the existence of a common factor that is responsible for age-related deterioration in cognitive and noncognitive processes. A multiple indicators, multiple causes model was used to examine the nature of this common factor and its relationship to age, gender, and the apolipoprotien E (APOE) genotype. The common factor was modeled by using 10 indicator variables with 374 participants aged between 77.4 and 98.7 years. A latent factor was identified, with all indicators except blood pressure loading significantly. This factor could be established in 2 age strata within the sample. After controlling for the effects of gender, APOE, and level of education, direct effects of age were seen on visual functioning and grip strength. APOE was significantly associated with memory but not with the common factor. The findings suggest that a number of specific processes may operate concurrently with the common cause factor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in reading with distraction: Sensory or inhibitory deficits?

Two experiments examined how sensory acuity affects age differences in susceptibility to interference in the reading-with-distraction task. In both experiments, older and younger adults read texts in an italic font and were required to ignore distractor words in an upright font. Experiment 1 examined whether the age-related increase in distractibility can be simulated in younger adults by reducing their visual acuity. Experiment 2 investigated whether the age differences in distractibility disappear if visual acuity is equated across all participants in both age groups. Both experiments showed that an impairment in visual acuity leads to increased interference in the reading-with-distraction task. However, older adults were much more impaired by the distractor material than younger adults with reduced visual acuity (Experiment 1). The age differences in the reading-with-distraction task persisted when visual acuity was equated between older and younger adults (Experiment 2). We conclude that the age-related increase in susceptibility to interference in the reading-with-distraction task is not solely due to perceptual deficits of older adults but arises from a deficit in higher cognitive processes such as inhibitory attention. Nevertheless, sensory acuity has to be taken into account as a potential confounding factor in perceptually demanding visual attention tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emergence of a powerful connection between sensory and cognitive functions across the adult life span: A new window to the study of cognitive aging?

Six hundred eighty seven individuals ages 25–103 years were studied cross-sectionally to examine the relationship between measures of sensory functioning (visual and auditory acuity) and intelligence (14 cognitive tasks representing a 5-factor space of psychometric intelligence). As predicted, the average proportion of individual differences in intellectual functioning connected to sensory functioning increased from 11% in adulthood (25–69 years) to 31% in old age (70–103 years). However, the link between fluid intellectual abilities and sensory functioning, albeit of different size, displayed a similarly high connection to age in both age groups. Several explanations are discussed, including a "common cause" hypothesis. In this vein, we argue that the increase in the age-associated link between sensory and intellectual functioning may reflect brain aging and that the search for explanations of cognitive aging phenomena would benefit from attending to factors that are shared between the 2 domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual function and cognitive aging: Differential role of contrast sensitivity in verbal versus spatial tasks.

Cognitive and sensory function are correlated in older adults. Sensory function may provide an index of neurological integrity (common-cause hypothesis). Declining sensory input may also directly impair cognition (direct-cause hypothesis). Accordingly, sensory function should more strongly predict cognitive performance and should account for more age-related variability in tasks with higher sensory demands. In a cross-sectional adult life span sample, visual contrast sensitivity was a better predictor and accounted for more of the age-related variability in high sensory-demand tasks, compared with low sensory-demand tasks, consistent with the direct-cause hypothesis. The results suggest a direct role for sensory function in cognitive aging when task conditions place heavy demands on sensory processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive Functioning as a Potential Mediator of Age-Related Cognitive Decline in Normal Adults.

Critical requirements for the hypothesis that executive functioning is a potential mediator of age-related effects on cognitive functioning are that variables assumed to reflect executive functioning represent a distinct construct and that age-related effects on other types of cognitive functioning are reduced when measures of executive functioning are statistically controlled. These issues were investigated in a study involving 261 adults between 18 and 84 years of age. Although age-related effects on various cognitive abilities were substantially reduced after statistical control of the variance in measures hypothesized to represent executive functioning, there was only weak evidence for the existence of distinct constructs corresponding to executive functioning or to aspects of executive control concerned with inhibition, updating, or time sharing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of cognitive stimulation on the relations between age and cognitive functioning.

To make a convincing argument that cognitive stimulation moderates age trends in cognition there must be (a) a negative relation between age and level of cognitive stimulation, (b) a positive relation between level of cognitive stimulation and level of cognitive functioning, and (c) evidence of an interaction between age and cognitive stimulation in the prediction of cognitive functioning. These conditions were investigated in a study in which 204 adults between 20 and 91 years of age completed an activity inventory and performed a variety of cognitive tasks. Only the 1st condition received empirical support, and, thus, the results of this study provide little evidence for the hypothesis that cognitive stimulation preserves or enhances cognitive functioning that would otherwise decline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use it or lose it: Engaged lifestyle as a buffer of cognitive decline in aging?

Data from the Victoria Longitudinal Study were used to examine the hypothesis that maintaining intellectual engagement through participation in everyday activities buffers individuals against cognitive decline in later life. The sample consisted of 250 middle-aged and older adults tested 3 times over 6 years. Structural equation modeling techniques were used to examine the relationships among changes in lifestyle variables and an array of cognitive variables. There was a relationship between changes in intellectually related activities and changes in cognitive functioning. These results are consistent with the hypothesis that intellectually engaging activities serve to buffer individuals against decline. However, an alternative model suggested the findings were also consistent with the hypothesis that high-ability individuals lead intellectually active lives until cognitive decline in old age limits their activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relations Between Cognitive Abilities and Measures of Executive Functioning.

Although frequently mentioned in contemporary neuropsychology, the term executive functioning has been a source of considerable confusion. One way in which the meaning of a variable can be investigated involves examining its pattern of relations with established cognitive abilities. This method was applied to a variety of variables hypothesized to assess executive functioning in 2 data sets, 1 consisting of 328 adults between 18 and 93 years of age and a 2nd composite data set based on nearly 7,000 healthy adults between 18 and 95 years of age. Most of the hypothesized executive functioning variables were strongly related to reasoning and perceptual speed abilities, and very few had any unique relations with age after taking into consideration the relations of age through the cognitive abilities. These results raise questions about the extent to which neuropsychological tests of executive functioning measure a distinct dimension of variation in normal adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance variability is related to change in cognition: Evidence from the Victoria Longitudinal Study.

Performance variability across repeated task administrations may be an important indicator of age-related cognitive functioning. In the present investigation, the authors examined whether age differences and change in inconsistency were related to 6-year (3 occasion) cognitive change. Inconsistency scores were computed from 4 reaction time tasks performed by 446 older adults (54-89 years). Replicating previous cross-sectional results, greater inconsistency was observed for older participants even after controlling for differences in response speed. New longitudinal results demonstrated (a) associations between inconsistency at baseline measurement and 6-year change in cognitive performance; (b) longitudinal change in inconsistency; and (c) intraindividual covariation between 6-year change in inconsistency and 6-year change in level of cognitive function. These findings support the view that performance variability serves as a marker of cognitive aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological functioning in older insomniacs with or without obstructive sleep apnea.

The relationships between neuropsychological functioning and sleep loss, sleep apnea, and hypoxemia were examined. Forty-five older insomniacs (M age?=?64.6 yrs) with or without sleep apnea were administered neuropsychological tests after 1 night of nocturnal monitoring in a sleep laboratory. The results showed few differences on cognitive and psychomotor performance between individuals with sleep disruptions alone compared with those whose insomnia was associated with sleep apnea and hypoxemia. There were no significant relationships between nocturnal sleep and respiratory variables and daytime functioning. Furthermore, cognitive and psychomotor performance in older insomniacs with or without sleep apnea revealed minimal impairment compared with age-matched normative data. The results suggest that when the severity of sleep disruptions is controlled, there are minimal differences in neuropsychological functioning of older adults with mild to moderate sleep apnea compared with those without apnea. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Representations of self across the life span.

This research extends a cognitive-developmental approach to examining age differences in self-representation from adolescence to mature adulthood and later life. The authors suggest that mature adults move from representations of self that are relatively poorly differentiated from others or social conventions to ones that involve emphasis on process, context, and individuality. Participants (n men?=?73, n women?=?76), ranging in age from 11 to 85 years, provided spontaneous accounts of their self-representations and responded to measures assessing cognitive and emotional functioning and broad dimensions of personality. On average, self-representation scores peaked in middle-aged adults and were lowest in the preadolescent and older adult age groups. Level of self-representation was related to cognitive and personality variables, but there was some evidence that the pattern of correlates shifted from younger (ages 15–45) to older (ages 46–85) age segments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurocognitive functions and everyday functions change together in old age.

Objective: Although neurocognitive functions are known to decline normatively with adult age, there is a common belief that everyday functions (e.g., paying bills, following medication instructions, making change, looking up telephone numbers in a phone book) are unaffected by these changes. Method: This hypothesis was examined by applying longitudinal growth models to data from a community-based sample of 698 adults (ages 65 to 94 years and living independently at baseline) who were repeatedly measured over five years on neurocognitive tests of executive reasoning, episodic memory, and perceptual speed, and on a number of tasks that adults should be reasonably expected to be able to perform in their day-to-day lives. Results: Individual differences in changes in neurocognitive performance were strongly correlated with individual differences in changes in performance on the everyday tasks. Alternatively, changes in self-reports of everyday functions were only weakly correlated with changes in performance on the neurocognitive tests and the everyday tasks. Conclusions: These results together suggest that normative neurocognitive aging has substantial consequences for the daily lives of older adults and that both researchers and clinicians should be cautious when interpreting self-reports of everyday functioning. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Global and domain-specific changes in cognition throughout adulthood.

Normative adult age-related decrements are well documented for many diverse forms of effortful cognitive processing. However, it is currently unclear whether each of these decrements reflects a distinct and independent developmental phenomenon, or, in part, a more global phenomenon. A number of studies have recently been published that show moderate to large magnitudes of positive relations among individual differences in rates of changes in different cognitive variables during adulthood. This suggests that a small number of common dimensions or even a single common dimension may underlie substantial proportions of individual differences in aging-related cognitive declines. This possibility was directly examined using data from 1,281 adults 18–95 years of age who were followed longitudinally over up to 7 years on 12 different measures of effortful processing. Multivariate growth curve models were applied to examine the dimensionality of individual differences in longitudinal changes. Results supported a hierarchical structure of aging-related changes, with an average of 39% of individual differences in change in a given variable attributable to global (domain-general) developmental processes, 33% attributable to domain-specific developmental processes (abstract reasoning, spatial visualization, episodic memory, and processing speed), and 28% attributable to test-specific developmental processes. Although it is often assumed that systematic and pervasive sources of cognitive decline only emerge in later adulthood, domain-general influences on change were apparent for younger (18–49 years), middle aged (50–69 years), and older (70–95 years) adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Identity processes and perceptions of physical functioning in adults: Theoretical and clinical implications.

Explored the relationship between identity and changes in physical functioning over the adult years. 242 adults (aged 40–95 yrs) rated themselves in 20 areas of normative functioning and identity processes. Measures included the Physical and Cognitive Change Scale, the Identity and Experiences Scale—Specific Aging, and the Rosenberg Self-Esteem Questionnaire. The findings indicate that adults as young as 40 are sensitive to age-related changes. Those 65 and older exhibited greater sensitivity to changes in competence. Identity assimilation was used most by adults under 65, particularly in the area of cognitive functioning. For individuals in both age groups, identity assimilation was positively related to self-esteem. The findings suggest that individuals may make behavioral adjustments without ruminating or becoming preoccupied, a strategy that may promote healthy adaptation to the aging process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What needs to be explained to account for age-related effects on multiple cognitive variables?

Structural equation methodology was used to investigate age-related influences across a number of cognitive variables in 204 adults ranging from 18 to 91 years of age with a hierarchical structure that contained 4 1st-order factors and 1 2nd-order common factor. Direct age relations were found to the common factor as well as to 1st-order speed and memory factors. Replicability of the findings was explored by investigating the same structure of age relations, using 2 different data sets, and a similar pattern was found in each. These results suggest that at least 3 statistically distinct types of age-related influences are operating on a wide variety of cognitive variables and presumably require separate explanatory mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress-related cognitive interference predicts cognitive function in old age.

Both subjective distress and cognitive interference have been proposed as mechanisms underlying the negative effects of stress on cognition. Studies of aging have shown that distress is associated with lower cognitive performance, but none have examined the effects of cognitive interference. One hundred eleven older adults (Mage=80) completed measures of working memory, processing speed, and episodic memory as well as self-report measures of subjective distress and cognitive interference. Cognitive interference was strongly associated with poorer performance on all 3 cognitive constructs, whereas distress was only modestly associated with lower working memory. The results suggest that cognitive process related to stress is an important predictor of cognitive function in advanced age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional reactivity across the adult life span: The cognitive pragmatics make a difference.

Previously, we found that during films about age-typical losses, older adults experienced greater sadness than young adults, whereas their physiological responses were just as large. In the present study, our goal was to replicate this finding and extend past work by examining the role of cognitive functioning in age differences in emotional reactivity. We measured the autonomic and subjective responses of 240 adults (age range = 20 to 70) while they viewed films about age-typical losses from our previous work. Findings were fully supportive of our past work: The magnitude of subjective reactions to our films increased linearly over the adult years, whereas there were no age differences on the level of physiological reactivity. We also found that the subjective reactions of adults with high pragmatic intelligence were of moderate size independent of their own age or the age relevance of the emotion elicitor. In contrast, the subjective reactions of adults low on pragmatic intelligence were more variable. Together, this evidence suggests that research on age differences in emotional reactivity may benefit from a perspective that considers individual difference variables as well as contextual variations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)