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.     

Age-related differences in acquisition of perceptual-motor skills: working memory as a mediator

Aging is associated with reduced performance on information processing speed, memory, and executive functions tasks. Although older adults are also less apt in acquiring new perceptual-motor skills, it is unclear whether and how skill acquisition difficulties are associated with age-related general cognitive differences. We addressed this question by examining structural relations among measures of cognitive resources (working memory) and indices of perceptual-motor skill acquisition (pursuit rotor and mirror tracing) in 96 healthy adults aged 19-80 years of age. Three competing structural models were tested: a single (common) factor model, a dual correlated factors model, and a hierarchical dual-factor model. The third model provided the best fit to the data, indicating age differences in simple perceptual-motor skill are partially mediated by more complex abilities.     

Age-Related Differences in Acquisition of Perceptual-Motor Skills: Working Memory as a Mediator

ABSTRACT

Aging is associated with reduced performance on information processing speed, memory, and executive functions tasks. Although older adults are also less apt in acquiring new perceptual-motor skills, it is unclear whether and how skill acquisition difficulties are associated with age-related general cognitive differences. We addressed this question by examining structural relations among measures of cognitive resources (working memory) and indices of perceptual-motor skill acquisition (pursuit rotor and mirror tracing) in 96 healthy adults aged 19–80 years of age. Three competing structural models were tested: a single (common) factor model, a dual correlated factors model, and a hierarchical dual-factor model. The third model provided the best fit to the data, indicating age differences in simple perceptual-motor skill are partially mediated by more complex abilities.     

Liens entre le déclin sensoriel et cognitif dans le vieillissement normal : revue critique de la littérature et apports de l’approche incarnée et située de la cognition

Biological aging impacts many organs including sensory's ones and the brain, and thus, cognition. Research has shown that the sensory and cognitive decline are positively correlated. The main data from this literature are firstly reviewed in the present article. Then, the four main hypotheses that are generally proposed to explain these associations are presented. According to them, sensory decline is supposed to cause cognitive decline, or vice-versa, or these concomitant changes result from the general alteration of the nervous system. However, none of them seems able to account for all of the existing data. Moreover, the precise mechanisms that may drive these associations remain to be clarified. The rest of the article is then dedicated to the embodied and situated cognition approach as it provides a particularly interesting and adequate framework to account for these links. Indeed, according to this approach, cognitive representations are grounded in their sensorimotor properties. In other words, cognitive functioning is not conceived as detached from sensory functioning, but instead directly dependent of it. Representations are thus thought to emerge from the sensorimotor simulation of the properties involved in these representations. Therefore, sensory decline should directly impact cognitive performance. It is then hypothesized that older adults have low-resolution representations decreasing the signal on noise ratio of traces, increasing sensorimotor interferences and thus decreasing cognitive performance. This approach leads to consider low and high levels of sensory and perceptual functioning, which are both impaired in aging. Therefore, the repercussion of the sensory-perceptual decline is not only valid for present processing, but also extend to all past knowledge. Several predictions are then proposed on (1) the link between high-level perceptual functioning and cognitive functioning in older adults; (2) the possible interaction in young adults between sensory and high-level perceptual functioning as a function of the level of interference of the material involved; (3) the possible link between the motor and cognitive functioning in older adults. The clinical consequences in terms of cognitive stimulation of such a perspective will close the article. It is proposed to develop a stimulation program based on pattern separation mechanism to better process sensory interference in order to train older adults to improve cognitive precision and thus performance.     

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.     

Validating age-related functional imaging changes in verbal working memory with acute stroke

Functional imaging studies consistently find that older adults recruit bilateral brain regions in cognitive tasks that are strongly lateralized in younger adults, a characterization known as the Hemispheric Asymmetry Reduction in Older Adults model. While functional imaging displays what brain areas are active during tasks, it cannot demonstrate what brain regions are necessary for task performance. We used behavioral data from acute stroke patients to test the hypothesis that older adults need both hemispheres for a verbal working memory task that is predominantly left-lateralized in younger adults. Right-handed younger (age ? 50, n = 7) and older adults (age > 50, n =21) with acute unilateral stroke, as well as younger (n =6) and older (n =13) transient ischemic attack (TIA) patients, performed a self-paced verbal item-recognition task. Older patients with stroke to either hemisphere had a higher frequency of deficits in the verbal working memory task compared to older TIA patients. Additionally, the deficits in older stroke patients were mainly in retrieval time while the deficits in younger stroke patients were mainly in accuracy. These data suggest that bihemispheric activity is necessary for older adults to successfully perform a verbal working memory task.     

社会隔离对老年人认知功能的影响：有调节的链式中介效应

基于5162名老年被试,探究社会隔离对老年人认知功能的影响、孤独感和抑郁的中介作用以及认知储备的调节作用。研究发现：（1）社会隔离显著负向预测认知功能,朋友隔离的预测作用较家庭隔离突出;（2）抑郁在其间发挥独立中介作用,孤独感和抑郁在其间发挥链式中介作用;（3）认知储备显著调节社会隔离、孤独感和抑郁对认知功能的影响,低认知储备是孤独感独立中介作用成立的条件,且低认知储备下抑郁的独立中介作用以及孤独感和抑郁的链式中介作用更强。研究结论对于老年人认知功能的保护工作具有积极意义。     

Are verbal transformations sensitive to age differences and stimulus properties?

Verbal transformations are illusory changes that arise from listening to a spoken word repeated over and over for a prolonged period of time. Past research has yielded some evidence of age differences in participants' reports of verbal transformations. The goal of the present study was to examine reports of illusory percepts in young and older adults to determine whether participant characteristics (i.e., age, cognitive integrity, hearing acuity, vocabulary knowledge, and mood) and differences in sensitivity to properties of the stimulus material could account for age-related declines in reports of illusory changes. We observed age-related declines in new forms (illusory percepts) but merely a trend in the same direction for transitions (changes from the veridical sensory experience to illusory percepts and reversals to either the veridical sensory experience or other percepts). There was no evidence that participant characteristics other than age accounted for reports of illusory changes. However, we found age differences in participants' sensitivity to properties of the stimulus material: Young adults but not older adults were sensitive to the frequency of the veridical percepts. In contrast, both age groups were sensitive to the size of the neighborhood of similar-sounding words. These findings are discussed regarding the transmission deficit hypothesis (MacKay & Burke, 1990).     

Managing daily life with age-related sensory loss: cognitive resources gain in importance

This paper investigates the role of cognitive resources in everyday functioning, comparing visually impaired, hearing impaired, and sensory unimpaired older adults. According to arguments that cognitive resources are of increased importance and a greater awareness of cognitive restrictions exists among sensory impaired individuals, in particular among visually impaired individuals, we hypothesized differential relationships between resources and outcomes when comparing sensory impaired and sensory unimpaired older adults. Findings are based on samples of 121 visually impaired, 116 hearing impaired, and 150 sensory unimpaired older adults (M = 82 years). Results from a sample of 43 dual sensory impaired older adults are reported for comparison. Assessment relied on established instruments (e.g., WAIS-R, ADL/IADL). Structural equation modeling showed that cognitive resources and behavior-related everyday functioning were more strongly related in the sensory impaired groups as compared to the sensory unimpaired group. Cognitive resources and evaluation of everyday functioning were significantly linked only among the sensory impaired groups. When medical condition was controlled for, these effects persisted. It is concluded that both cognitive training as well as psychosocial support may serve as important additions to classic vision and hearing loss rehabilitation.     

The relationship between metacognitive awareness of olfactory ability and age in people reporting chemosensory disturbances

When determining how much to rely on olfactory information, accurate estimates of olfactory ability are important. Nevertheless, metacognitive errors regarding olfactory ability are common in the normal population. Are older adults less accurate at estimating olfactory ability, or do they simply tend to make a particular type of estimation error? We examined data from 203 patients, all of whom self-rated olfactory ability and then were tested with the Odorant Confusion Matrix. The patients' self-reports did not match the objective measure of olfactory ability in 42% of the cases, thus demonstrating a high level of impairment in metacognitive knowledge. Neither the cause of loss nor the patient's age was related to the inability to accurately estimate olfactory loss, but both contributed to the type of metacognitive errors patients made. Younger patients tended to underestimate their olfactory ability, thus behaving similarly to patients with "blindsight" who demonstrate residual visual function in the absence of awareness. Older patients tended to overestimate their olfactory ability, thus making the metacognitive error of deficit unawareness that is observed in a number of other clinical syndromes. These findings indicate that older patients are not necessarily more likely to make errors in estimating their olfactory ability; rather, they are more prone to a particular type of metacognitive error than are younger patients.     

No inhibitory deficit in older adults' episodic memory

Selectively retrieving a subset of previously studied material can cause forgetting of the unpracticed material. Such retrieval-induced forgetting is attributed to an inhibitory mechanism recruited to resolve interference among competing items. According to the inhibition-deficit hypothesis, older people experience a specific decline in inhibitory function and thus should show reduced retrieval-induced forgetting. However, the results of the two experiments reported here show the same amount of retrieval-induced forgetting in younger and older adults. These results indicate that retrieval inhibition is intact in older adults' episodic recall. The findings suggest that the common view of a general inhibitory deficit in older adults needs to be updated and that older adults show intact inhibition in some cognitive tasks and deficient inhibition in others.     

Aging, source memory, and misrecollections

The authors propose an illusory recollection account of why cognitive aging is associated with episodic memory deficits. After listening to statements presented by either a female or a male speaker, older adults were prone to misrecollecting past events. The authors' illusory recollection account is instantiated in a new illusory recollection signal detection model that provides a better fit of older adults' data than does the standard signal detection model. They observed that age-related differences in source memory (as measured by source d' scores) virtually disappear after accounting for the occurrence of illusory recollections. These data suggest that age-related source memory impairments are not due to older adults' remembering less diagnostic source information and having to guess more. Instead, older adults appear to misremember past events more often than younger adults.     

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 apolipoprotein 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 any common cause factor.     

Self-regulation and recall: growth curve modeling of intervention outcomes for older adults

Memory training has often been supported as a potential means to improve performance for older adults. Less often studied are the characteristics of trainees that benefit most from training. Using a self-regulatory perspective, the current project examined a latent growth curve model to predict training-related gains for middle-aged and older adult trainees from individual differences (e.g., education), information processing skills (strategy use) and self-regulatory factors such as self-efficacy, control, and active engagement in training. For name recall, a model including strategy usage and strategy change as predictors of memory gain, along with self-efficacy and self-efficacy change, showed comparable fit to a more parsimonious model including only self-efficacy variables as predictors. The best fit to the text recall data was a model focusing on self-efficacy change as the main predictor of memory change, and that model showed significantly better fit than a model also including strategy usage variables as predictors. In these models, overall performance was significantly predicted by age and memory self-efficacy, and subsequent training-related gains in performance were best predicted directly by change in self-efficacy (text recall), or indirectly through the impact of active engagement and self-efficacy on gains (name recall). These results underscore the benefits of targeting self-regulatory factors in intervention programs designed to improve memory skills.     

Structural equation models of relationships between exercise and cognitive abilities

Data were obtained from 300 men and women aged 55 to 91. Separate structural equation models of relationships between physical exercise and 3 cognitive performance variables--reaction time, working memory, and reasoning--fit the data well. Other variables in the models were age, health, education, and morale. Age and exercise affected each performance variable directly; education had a direct effect on reasoning only. There were also indirect effects of age and health on performance variables, mediated through exercise. The main hypothesis of the study, that exercise contributes to performance, was supported. A large decrease in model fit resulted when the path from exercise to each performance variable was deleted. Hypotheses that age-related deficits are primarily accounted for by lack of exercise or by poor health were not supported.     

Dual-process models of associative recognition in young and older adults: evidence from receiver operating characteristics

In 3 experiments, young and older adults studied lists of unrelated word pairs and were given confidence-rated item and associative recognition tests. Several different models of recognition were fit to the confidence-rating data using techniques described by S. Macho (2002, 2004). Concordant with previous findings, item recognition data were best fit by an unequal-variance signal detection theory model for both young and older adults. For both age groups, associative recognition performance was best explained by models incorporating both recollection and familiarity components. Examination of parameter estimates supported the conclusion that recollection is reduced in old age, but inferences about age differences in familiarity were highly model dependent. Implications for dual-process models of memory in old age are discussed.     

Current perspectives on Rorschach performance among older adults

Review of empirical studies of Rorschach performance by older adults (age 65+) indicates that previous research findings of declining cognitive flexibility and impoverishment of personality may be artifacts of design methodologies that have failed to adequately account for biosocial-psychological differences between age groups and within the older age group itself. When findings are assessed in terms of variables reflective of age cohort as well as residential status, diagnosis, health status, and test-taking attitude, important data become available. Suggestions concerning test interpretation are offered in lieu of the current lack of age matched base rates for Rorschach scoring variables.     

Effects of age simulation and age on motor sequence learning: Interaction of age-related cognitive and motor decline

Aging is known to lead to decrements in sensory and cognitive functioning and motor performance. The purpose of the present experiment was twofold: a) We assessed the influence of wearing an age simulation suit on motor sequence learning, cognitive speed tasks and far visual acuity in healthy, younger adults. b) We evaluated the interaction of cognitive aging and declining motor sequence learning in older adults. In a between-subjects design we tested 11 younger adults (M_age = 23.6 years) without the age suit, 12 younger adults wearing the age suit (M_age = 23.2 years), and 23 older adults (M_age = 72.6 years). All participants learned a simple, spatial-temporal movement sequence on two consecutive days, and we assessed perceptual processing speed (Digit Symbol Substitution test and Figural Speed test) and far visual acuity. Wearing an age simulation suit neither affected the learning of the simple motor sequence nor the performance at the cognitive speed tasks in younger adults. However, far visual acuity suffered from wearing the suit. Younger adults with and without the suit showed better motor sequence learning compared to older adults. The significant correlations between the cognitive speed tests and the motor learning performance in older adults indicated that cognitive aging partially explains some of the variance in age-related motor learning deficits.     

Age-related deficits in reality monitoring of action memories

The authors describe 3 theoretical accounts of age-related increases in falsely remembering that imagined actions were performed (A. K. Thomas & J. B. Bulevich, 2006). To investigate these accounts and further explore age-related changes in reality monitoring of action memories, the authors used a new paradigm in which actions were (a) imagined only, (b) actually performed, or (c) both imagined and performed. Older adults were more likely than younger adults to misremember the source of imagined-only actions, with older adults more often specifying that the action was imagined and also that it was performed. For both age groups, illusions that the actions were only performed decreased as repetitions of the imagined-only events increased. These patterns suggest that both older and younger adults use qualitative characteristics when making reality-monitoring judgments and that repeated imagination produces richer records of both sensory details and cognitive operations. However, sensory information derived from imagination appears to be more similar to that derived from performance for older adults than for younger adults.     

Identification of odors of edible and nonedible stimuli as affected by age and gender

This study investigated cued odor identification performance with a set of 64 natural common odors (half of edible and half of nonedible stimuli) in three groups of participants: one group of 30 young adults (mean age 25.3 years, range 18-30, SD 3.1) and two groups of older adults-20 young-old (mean age 64.4 years, range 60-69, SD 2.8) and 21 old-old (mean age 74.6 years, range 70-79, SD 2.5). The results showed that 49 of the 64 odors were correctly identified by over 70% of the participants in all groups. The odor identification performance of the young-old adults did not differ from that of the young adults. However, the oldest group showed a significant loss of performance in the task. Women in the young-old group performed better than men, whereas no gender differences were found in the other two age groups. The data obtained in this study will be useful for further perceptual and memory studies conducted in the olfactory modality with young as well as with older participants.