More expertise for a better perspective: Task and strategy-driven adaptive neurofunctional reorganization for word production in high-performing older adults

The suggestion that neurofunctional reorganization may contribute to preserved language abilities is still emerging in aging studies. Some of these abilities, such as verbal fluency (VF), are not unitary but instead rely on different strategic processes that are differentially changed with age. Younger (n = 13) and older adults (n = 13) carried out an overt self-paced semantic and orthographic VF tasks within mixed fMRI design. Our results suggest that patterns of brain activation sustaining equivalent performances could be underpinned by different strategies facing brain changes during healthy aging. These main findings suggest that temporally mediated semantic clustering and frontally mediated orthographic switching were driven by evolutive neurofunctional resources in high-performing older adults. These age-related activation changes can appear to be compatible with the idea that unique neural patterns expressing distinctive cognitive strategies are necessary to support older adults’ performance on VF tasks.     

Aging and Individual Variation in Interhemispheric Collaboration and Hemispheric Asymmetry

ABSTRACT

Thirty younger (Mean Age = 19.9 years) and 20 older adults (Mean Age = 74.7 years) performed Physical and Name Identity letter-matching tasks (matches were either within or between hemispheres) to study age-related changes in 1) the efficiency with which the two hemispheres interact with each other and 2) hemispheric asymmetry. In order to determine whether age-related effects were associated with differences in cognitive resources, the same individuals completed a set of memory span tasks. Performance on the letter-matching tasks indicated that the costs of interhemispheric collaboration were greater for older than for younger participants. However, within the older group, the advantage of spreading processing across both hemispheres increased as memory span decreased, suggesting that older individuals who are challenged by cognitive complexity are more likely to show increased benefits from between-hemisphere processing than individuals who are not so challenged. There was also an overall left visual field/right hemisphere advantage for the younger but not for the older group, suggesting greater age-related declines in right- than left-hemisphere function.     

Age-related changes in processing speed modulate context use during idiomatic ambiguity resolution

ABSTRACT

The goal of the current study was to investigate whether age-related changes in processing speed, as indexed by verbal fluency, modulate context use in the resolution of ambiguous idioms (e.g., tie the knot). Younger and older adults completed a cross-modal priming experiment where they decided whether visual word targets were related in meaning to idiomatically or literally biased auditory sentence primes. Older adults with high verbal fluency, similar to younger adults, showed context-dependent facilitation in both biasing sentence contexts. In contrast, older adults with low verbal fluency did not show facilitation of literal meanings in literally biased sentence contexts, likely because they had difficultly inhibiting the dominant figurative meaning. These findings argue that age-related changes in context use during ambiguity resolution are restricted to older adults with reduced processing speed. The results also suggest that verbal fluency may reflect the speed in recruiting frontally-mediated selection mechanisms during ambiguity resolution.     

Volunteering in older adulthood is associated with activity engagement and cognitive functioning

ABSTRACT

Introduction: Given evidence that activity engagement in older adulthood can have protective effects on the aging brain, we investigated the idea that volunteering in the community, which often encompasses social, cognitive, and physical activity, might benefit cognition.

Method: Ninety-one retired 65- to 75-year-olds reported their sociodemographic characteristics, wellbeing, volunteering, and activity engagement. They also completed computerized cognitive tests that tapped specific functions known to decline disproportionately with age.

Results: Volunteering at least monthly was associated with better working memory and more social and cognitive activity. Mediation analyses indicated that volunteering was indirectly related to switching performance via cognitive activity. However, the volunteering-working memory association did not depend on activity engagement, leaving the underpinning mechanisms unclear.

Conclusions: These findings provide new insight into positive associations between older people’s volunteering, activity engagement, and cognitive functioning. However, further work is needed to understand the mechanisms that drive volunteering-cognition links, and to establish causality.     

Adult age differences in memory for schema-consistent and schema-inconsistent objects in a real-world setting

The present study examined age-related differences in the inconsistency effect, in which memory is enhanced for schema-inconsistent information compared to schema-consistent information. Young and older adults studied schema-consistent and schema-inconsistent objects in an academic office under either intentional or incidental encoding instructions, and were given two recognition tests either immediately or after 48 hr: A yes/no item recognition test that included modified remember/know judgments and a token recognition test that required determining whether an original object was replaced with a different object with the same name. Young and older adults showed equivalent inconsistency effects in both item and token recognition tests, although older adults reported phenomenologically less rich memories of schema-inconsistent objects relative to young adults. These findings run counter to previous reports suggesting that aging is associated with processing declines at encoding that impair memory for details of schema-inconsistent or distinctive events. The results are consistent with a retrieval-based account in which age-related difficulties in retrieving contextual details can be offset by environmental support.     

Visual scanning patterns and executive function in relation to facial emotion recognition in aging

ABSTRACT

Objective: The ability to perceive facial emotion varies with age. Relative to younger adults (YA), older adults (OA) are less accurate at identifying fear, anger, and sadness, and more accurate at identifying disgust. Because different emotions are conveyed by different parts of the face, changes in visual scanning patterns may account for age-related variability. We investigated the relation between scanning patterns and recognition of facial emotions. Additionally, as frontal-lobe changes with age may affect scanning patterns and emotion recognition, we examined correlations between scanning parameters and performance on executive function tests. Methods: We recorded eye movements from 16 OA (mean age 68.9) and 16 YA (mean age 19.2) while they categorized facial expressions and non-face control images (landscapes), and administered standard tests of executive function. Results: OA were less accurate than YA at identifying fear (p < .05, r = .44) and more accurate at identifying disgust (p < .05, r = .39). OA fixated less than YA on the top half of the face for disgust, fearful, happy, neutral, and sad faces (p values < .05, r values ≥ .38), whereas there was no group difference for landscapes. For OA, executive function was correlated with recognition of sad expressions and with scanning patterns for fearful, sad, and surprised expressions. Conclusion: We report significant age-related differences in visual scanning that are specific to faces. The observed relation between scanning patterns and executive function supports the hypothesis that frontal-lobe changes with age may underlie some changes in emotion recognition.     

Proactive interference in working memory is related to adult age and cognitive factors: cross-sectional and longitudinal evidence from the Betula study

ABSTRACT

In working memory (WM), successful maintenance of information is affected by interference. Older adults may be especially susceptible to the effects of interference, which may cause age-related cognitive impairments. A relative score of IC was derived from cross-sectional (n = 869) and longitudinal (n = 443) data to investigate (1) if IC is reduced in normal aging, (2) if individual differences in IC related to individual performance in other cognitive domains, and (3) if 5-year change in IC is related to change in general cognition. Older age was associated with reduced IC, but no decline in IC occurred over 5 years. Also, the ability to control interference in WM was related to performance in episodic memory, verbal fluency, and block design. We also found that IC mediates the relationship between age and cognition, suggesting that age-related cognitive decline is linked to IC. Finally, we demonstrate that change in IC was related to decline in episodic memory.     

Age-related differences in associative memory depend on the types of associations that are formed

ABSTRACT

Building on well-established findings of age-related decline in associative memory, we examined whether the magnitude of age differences depends on the types of associations that are formed. Specifically, because of predominant age-related changes in the hippocampus, we expected to find larger age differences in recognition of between-domain than within-domain associations. Twenty younger and 20 older healthy adults were given two associative recognition tests, using face–name and word–word pairs, that were matched for difficulty level. As hypothesized, a three-way interaction indicated that, relative to item recognition, age differences in associative recognition were greater for between-domain face–name associations than for within-domain word–word associations. This dissociation is consistent with the idea that the hippocampus plays a prominent role in binding information received from distal neocortical regions. The discussion focuses on the roles of recollection and familiarity in supporting associative memory as well as implications for the remediation of age-related memory decline.     

The role of regional heterogeneity in age-related differences in functional hemispheric asymmetry: an fMRI study

Neuroimaging literature has documented age-related hemispheric asymmetry reduction in frontal regions during task performances. As most studies employed working memory paradigms, it is therefore less clear if this pattern of neural reorganization is constrained by working memory processes or it would also emerge in other cognitive domains which are predominantly lateralized. Using blocked functional magnetic resonance imaging (fMRI), the present study used a homophone judgment task and a line judgment task to investigate age-related differences in functional hemispheric asymmetry in language and visuospatial processing respectively. Young and older adults achieved similar task accuracy although older adults required a significantly longer time. Age-related functional hemispheric asymmetry reduction was found only in dorsal inferior frontal gyrus and was associated with better performance when the homophone condition was contrasted against fixation, and not line condition. Our data thus highlights the importance of considering regional heterogeneity of aging effects together with general age-related cognitive processes.     

Aging in cognitive control of social processing: evidence from the attention network test

ABSTRACT

Aging seems to be associated with impairment of attentional network functioning. It is not known whether social information can modulate this age-related decline. We used three variants of Attention Network test to examine the age-related decline of attentional effects in response to stimuli with and without social-cognitive content. Three groups of younger, middle-aged, and older participants performed the ANT, using fish, drawings, or photographs of faces looking to the left or right as target and flanker stimuli. The results showed that both executive attention and alerting were more resistant to the age-related decline with social stimuli and that orienting attention scores showed a progressive increase with age in the presence of this kind of stimuli. These findings underline the importance of social information in modulating and contrasting the age-related decline and support the status of human faces as a special class of visual stimuli for the human attentional systems.     

Saccadic eye movements: what do they tell us about aging cognition?

Although the relationship between age-related cognitive decline and saccadic eye movement (SEM) deficits has been outlined, specific cognitive alterations underlying age-related changes in saccadic performance remain unclear. This study attempted to better understand the nature of aging effects on SEMs. We compared SEMs in younger and older adults in prosaccade (PS) and antisaccade (AS) tasks under gap, step, and overlap conditions. We also examined relationships between these performances and several neuropsychological scores. Twenty-eight younger adults (YA), 24 older adults under 65 years (OA_<65) and 24 over 65 years (OA_>65) of age completed a neuropsychological evaluation, PS and AS tasks. Our results showed that latencies, AS cost, time to correct AS errors, and uncorrected AS, increased with aging. YA showed higher overlap effects than OA_>65 and OA_<65. Importantly, correlations and regressions revealed close relationships not only between latencies and processing speed measures but also between the AS cost and the inhibition process measures. Correct saccades and the time to correct AS errors were closely related to the inhibition process and cognitive flexibility measures. These findings suggest that the progressive age-related decline of processing speed and executive attention are associated with, and can be highlighted though SEMs in PS and AS tasks.     

A Sensory Origin for Color-Word Stroop Effects in Aging: Simulating Age-Related Changes in Color-vision Mimics Age-Related Changes in Stroop

ABSTRACT

An increase in Stroop effects with age can be interpreted as reflecting age-related reductions in selective attention, cognitive slowing, or color-vision. In the present study, 88 younger adults performed a Stroop test with two color-sets, saturated and desaturated, to simulate an age-related decrease in color perception. This color manipulation with younger adults was sufficient to lead to an increase in Stroop effects that mimics age-effects. We conclude that age-related changes in color perception can contribute to the differences in Stroop effects observed in aging. Finally, we suggest that the clinical applications of Stroop take this factor into account.     

Age-related Changes in Postural Sway During Sit-to-stand in Typical Children and Children with Cerebral Palsy

Objective: To assess age-related changes in postural sway during sit-to-stand (STS) in typical children (TC) and children with mild cerebral palsy (CP). Methods: Thirty-five TC and 23 children with mild CP were allocated in four different age groups: 5–6, 7–9, 10–12, and 13–15 years; they all performed STS movements over a force plate. Anterior-posterior and medial-lateral amplitude of center of pressure (CoP) displacement, area and velocity of CoP sway were analyzed and compared between the age groups for TC and children with CP. Results: TC at 5 to 6 years of age showed higher values of anterior-posterior CoP displacement and Area of CoP sway than at 10–12 years, during the stabilization phase. There were no age-related changes for CP. Conclusion: TC change their postural sway during the last STS phase over the years, reducing their body sway. Children with CP did not show age-related changes in sway during STS, reflecting a distinct rhythm of postural control development in this population.     

Mechanisms of postural control in older adults based on surface electromyography data

ObjectivesThe present study aimed to clarify the mechanisms of postural control during standing in older adults and document the mechanisms of age-related motor control based on changes in muscle activities.MethodsA total of 26 healthy male adults (older adult group, ≥65–78 years: n = 16; younger adult group, 20–23 years: n = 10) participated in this study. Ground reaction force and kinematic data of the lower limbs (hip, knee, and ankle), and electromyographic data from 6 postural muscles on the right side were recorded and quantified for each motor phase during rapid voluntary center of pressure (COP) shift.ResultsAlthough hip strategy was more frequently observed in older adults than in young adults (56.3% vs. 20.0%), no muscle activity of hip agonists was observed in some (31.3%) older adults. Furthermore, older adults had a statistically significant delay in the inhibition of postural muscles during anticipatory postural adjustments (p < 0.05). After the onset of COP motion, the co-contraction time between agonists and antagonists was significantly prolonged in the older adults than in the younger adults (p < 0.05), and the reciprocal muscle pattern was unclear in the older adults. Prior to the termination of movement, agonist activity continued longer in the older adult group than in the younger adult group; that is, inhibition was insufficient in the older adult group.ConclusionA series of postural strategies during the voluntary movement task were altered in older adults, and this was significantly related not only with the activation but also the inhibition of postural muscles.     

The effects of daily co-occurrence of affect on older adults’ reactivity to health stressors

Objectives: The present study examined age differences among older adults in the daily co-occurrence of affect and its potential role in buffering the negative effects of health stressors.

Design: Participants were from the Veterans Affairs Normative Aging Study and included 249 young-old adults (age = 60–79 years, M = 71.6) and 64 old-old adults (age = 80–89, M = 82.9) who completed questionnaires assessing stressors, physical health symptoms, and positive and negative affect for eight consecutive days.

Results: An independent samples t-test showed young-old and old-old adults did not significantly differ in their mean levels of daily co-occurrence of affect. The between-person relationships among stressors, health and daily co-occurrence of affect revealed that neither stressors nor health were significantly related to daily co-occurrence of affect. However, results from a multilevel model revealed a three-way cross-level interaction (health stressor × age group × co-occurrence of affect) where old-old adults with higher levels of co-occurrence of affect were less emotionally reactive to health stressors than young-old adults.

Conclusion: These findings provide support for the assertion that co-occurrence of affect functions in an adaptive capacity and highlight the importance of examining domain-specific stressors.     

Decline of Hip Joint Movement Relates to Overestimation of Maximum Forward Reach in Elderly Persons

The authors aimed to characterize age-related changes in the performance of maximum reach and identify kinematic parameters that explain the age-related discrepancy between perceived and actual maximum reach distance. Maximum reach was evaluated in 22 younger women (21.3 years old) and 20 older women (81.2 years old). Both the perceived and actual maximum forward reach and forward excursion of the center of pressure was shorter in older women. Older women also overestimated their maximum reach distance to a greater extent. Decline of movement at the hip joint specifically correlated with both the maximum distance and the overestimation. Based on these results, decline of hip control may be a primary factor for the age-related retardation of perceived and actual maximum reach.     

Age-related differences in idea generation and selection for propositional language

Conceptual preparation mechanisms such as novel idea generation and selection from amongst competing alternatives are critical for language production and may contribute to age-related language deficits. This study investigated whether older adults show diminished idea generation and selection abilities, compared to younger adults. Twenty younger (18–35 years) and 20 older (60–80 years) adults completed two novel experimental tasks, an idea generation task and a selection task. Older participants were slower than younger participants overall on both tasks. Importantly, this difference was more pronounced for task conditions with greater demands on generation and selection. Older adults were also significantly reduced on a semantic, but not phonemic, word fluency task. Overall, the older group showed evidence of age-related decline specific to idea generation and selection ability. This has implications for the message formulation stage of propositional language decline in normal aging.     

Takeover performance of older drivers in automated driving: A review

IntroductionThe introduction of automated vehicles to the road environment brings new challenges for older drivers. Level 3 of conditional automation requires drivers to take over control of their vehicle whenever the automated system reaches its limits. Even though autonomous vehicles may be of great benefit to older drivers in terms of safely maintaining their mobility, a better understanding of their takeover performance remains crucial. The objective of this review of the literature is to shed more light on the effects that aging has on takeover performance during automated driving.MethodsThree database searches were conducted: PsychINFO, Web Of Sciences, and TRID. Studies from the last decade which included groups of older drivers were reviewed.ResultsAfter checking through abstracts and texts of articles, 9 articles, 4 proceedings papers, and 1 technical report were included in this review. All studies included a driving simulator that refers to level 3 of automation (which requires supervision by the driver). Five out of fourteen studies showed that older adults had poorer takeover performance (in terms of takeover time and takeover quality) than younger adults. However, several factors, such as the type of non-driving related task (NDRT), were seen to influence takeover performance in older adults. Speed, type and duration of notification interval, distribution and duration of driving modes, and number of takeovers were all also factors of influence.ConclusionThis review synthesizes the results of 14 articles which investigate the effects of age-related changes on takeover performance. Various external factors as NDRTs, speed, type and duration of notification to take over, duration of the automated phase, distribution of the automated/manual phases may affect takeover performance in older adults. Even if the majority of articles showed that older adults are globally slower at taking over a vehicle than younger adults, findings concerning take over quality yield divergent results. It's probably due to age related cognitive changes, particularly in executive functions or to a great heterogeneity in this population. This literature review highlights the need to develop new research on the impact of aging on takeover performance.     

Hemispheric lateralization in aging: Interest of the verbal-manual concurrency paradigm

ABSTRACT

Introduction: The aim of this study was to evaluate whether the classic asymmetry seen in hemispheric functioning is modified in older adults by using a verbal-manual concurrency task. Method: Thirty-five right-handed participants divided into two groups according to age (15 older participants, mean age: 68 ± 8 years, without cognitive decline and 20 younger participants, mean age: 23 ± 2 years) had to perform a 30-second uni-manual tapping task, in both a single task (tapping alone) and dual task (tapping and performing a letter fluency task together) condition. Results: In younger participants, the letter fluency task disrupted the right hand more than the left hand whereas, in older participants, the letter fluency task disrupted both hands equally. Conclusion: These results should be considered preliminary data using a behavioral dual task condition, which might be useful for studying lateralized hemispheric functioning and the processes of divided attention during aging.     

Aging Effects on Recollection and Familiarity: The Role of White Matter Hyperintensities

ABSTRACT

Previous studies have indicated that aging is associated with declines in recollection whereas familiarity-based recognition is left largely unaffected. The brain changes underlying these recollection declines are yet not well understood. In the current study we examined the role of white matter integrity as measured by white matter hyperintensities (WMH) on age-related changes in recollection and familiarity. Recognition was measured using a remember/know procedure (Experiment 1) and a source-memory process-dissociation procedure (Experiment 2). Robust age related declines in recollection were observed, but there was no evidence that white matter damage was related to the observed memory declines. Although future studies with larger samples will be necessary to fully characterize the role of WMH in normal age-related declines in different types of memory, the results suggest that declines in recollection are not strongly related to the brain changes indexed by WMHs.