Age-related Decrements Research Articles

Age Differences in Decoding Pain from the Facial Expression of Healthy Individuals and Patients with Dementia.

Patients with dementia, whose ability to provide self-report of pain is often impaired, are in crucial need of observers who can detect the patients' pain-indicative behaviors appropriately, to initiate treatment. The facial display of pain promises to be especially informative for that purpose. The age of the observer has been shown to have a critical influence on observational emotion recognition (with age-related decrements in facial emotion recognition) but has not yet been studied as such for pain recognition. For that purpose, 24 young (mean age: 24 years) and 22 older (mean age: 70 years) observers watched 120 video clips, showing facial expressions of young and old individuals with and without dementia during slight and moderate noxious stimulation. After each clip, observers were asked to rate how much pain the observed individual might have experienced. Young observers were superior in grading different levels of pain in the observed individuals; furthermore, their ratings corresponded better with the self-ratings of the observed individuals. However, the performance of the older observers was still sufficient as regards the differentiation of different pain levels and prediction of self-report in others. Age does not only lead to a decline in recognition of facial expressions of emotions but age also affects the quality of observational pain recognition in others. However, given that older observers' performance was only slightly reduced, clearly suggests that older caregivers are surely not at risk of becoming visual agnostic for the pain in others.

Polygenic risk for coronary artery disease is associated with cognitive ability in older adults.

Background: Coronary artery disease (CAD) is associated with cognitive decrements and risk of later dementia, but it is not known if shared genetic factors underlie this association. We tested whether polygenic risk for CAD was associated with cognitive ability in community-dwelling cohorts of middle-aged and older adults. Methods: Individuals from Generation Scotland: Scottish Family Health Study (GS:SFHS, N = 9865) and from the Lothian Birth Cohorts of 1921 (LBC1921, N = 517) and 1936 (LBC1936, N = 1005) provided cognitive data and genome-wide genotype data. Polygenic risk profile scores for CAD were calculated for all of the cohorts using the largest available genome-wide association studies (GWAS) data set, the CARDIoGRAM consortium (22 233 cases and 64 762 controls). Polygenic risk profile scores for CAD were then tested for their association with cognitive abilities in the presence and absence of manifest cardiovascular disease. Results: A meta-analysis of all three cohorts showed a negative association between CAD polygenic risk and fluid cognitive ability (β = −0.022, P = 0.016), verbal intelligence (β = −0.024, P = 0.011) and memory (β = −0.021, P = 0.028). Conclusions: Increased polygenic risk for CAD is associated with lower cognitive ability in older adults. Common genetic variants may underlie some of the association between age-related cognitive decrements and the risk for CAD.

Influences of age, tongue region, and chorda tympani nerve sectioning on signal detection measures of lingual taste sensitivity

Although the ability to taste is critical for ingestion, nutrition, and quality of life, a clear understanding of the influences of age, sex, and chorda tympani (CT) resection on taste function in different regions of the anterior tongue is generally lacking. In this study we employed criterion-free signal detection analysis to assess electric and chemical taste function on multiple tongue regions in normal individuals varying in age and sex and in patients with unilateral CT resections. The subjects were 33 healthy volunteers, ranging from 18 to 87years of age, and 9 persons, 27 to 77years of age, with unilateral CT lesions. The influences of age, sex, tongue region, and chorda tympani resections on signal detection sensitivity (d′) and response bias (β) measures was assessed in 16 tongue regions to weak electric currents and solutions of sucrose, sodium chloride, and caffeine. Significant age-related decrements in d′ were found for sucrose (p=0.012), sodium chloride (p=0.002), caffeine (p=0.006), and electric current (EC) (p=0.0001). Significant posterior to anterior, and medial to lateral, gradients of increasing performance were present for most stimuli. β was larger on the anterior than the posterior tongue for the electrical stimulus in the youngest subjects, whereas the opposite was true for sucrose in the oldest subjects. No sex differences were apparent. d′ was depressed ipsilateral to the CT lesion side to varying degrees in all tongue regions, with the weakest influences occurring on the medial and anterior tongue. CT did not meaningfully influence β. This study is the first to employ signal detection analysis to assess the regional sensitivity of the tongue to chemical and electrical stimuli. It clearly demonstrates that tongue regions differ from one another in terms of their age-related sensitivity and their susceptibility to CT lesions.

The beneficial effects of berries on cognition, motor behaviour and neuronal function in ageing.

Previously, it has been shown that strawberry (SB) or blueberry (BB) supplementations, when fed to rats from 19 to 21 months of age, reverse age-related decrements in motor and cognitive performance. We have postulated that these effects may be the result of a number of positive benefits of the berry polyphenols, including decreased stress signalling, increased neurogenesis, and increased signals involved in learning and memory. Thus, the present study was carried out to examine these mechanisms in aged animals by administering a control, 2 % SB- or 2 % BB-supplemented diet to aged Fischer 344 rats for 8 weeks to ascertain their effectiveness in reversing age-related deficits in behavioural and neuronal function. The results showed that rats consuming the berry diets exhibited enhanced motor performance and improved cognition, specifically working memory. In addition, the rats supplemented with BB and SB diets showed increased hippocampal neurogenesis and expression of insulin-like growth factor 1, although the improvements in working memory performance could not solely be explained by these increases. The diverse polyphenolics in these berry fruits may have additional mechanisms of action that could account for their relative differences in efficacy.

Transforming medicine through physiology.

Claude Bernard is considered by many to be the father of modern physiology and medicine. In his 1865 book, An Introduction to the Study of Experimental Medicine , Bernard introduced the scientific method to the field of medicine and thereby initiated the concept of evidenced-based medicine. In this

The Technological Age: The Effects of Perceived Age in Technology Training

The purpose of this study was to investigate if chronological age sparks negative expectancies thus initiating a self-fulfilling prophecy in technology training interactions. Data were obtained from undergraduate students (age ≤ 30) paired in 85 trainer–trainee dyads and examined through the actor-partner interdependence model. Trainer and trainee age (younger or older) were manipulated in this laboratory experiment by presenting pre-selected photographs coupled with voice enhancing software. As compared to younger trainees, ostensibly older trainees evoked negative expectancies when training for a technological task, which ultimately manifested in poorer training interactions and trainer evaluations of trainee performance. Identifying a connection between chronological age and negative expectancies in technology training advances our theoretical understanding of sources contributing to older trainees’ poorer performance in workforce training programs. This study provides evidence of a negative relationship between trainees’ chronological age and trainers’ expectations for trainee success and subsequent training evaluations. Such knowledge offers initial support for a “train-the-trainer” intervention through educating trainers on the potential dangers of age-based stereotypes, which could help to reduce age-based performance discrepancies. This is the first study to manipulate age during training thus isolating the influence of age-based stereotypes on training experiences. Given that potential age-related performance decrements in capability and motivation can be eliminated as explanations, this evidence of poorer interactions and outcomes for older workers is critical.

Elevated hippocampal resting-state connectivity underlies deficient neurocognitive function in aging.

The brain is not idle during rest. Functional MRI (fMRI) studies have identified several resting-state networks, including the default mode network (DMN), which contains a set of cortical regions that interact with a hippocampus (HC) subsystem. Age-related alterations in the functional architecture of the DMN and HC may influence memory functions and possibly constitute a sensitive biomarker of forthcoming memory deficits. However, the exact form of DMN-HC alterations in aging and concomitant memory deficits is largely unknown. Here, using both task and resting data from 339 participants (25-80 y old), we have demonstrated age-related decrements in resting-state functional connectivity across most parts of the DMN, except for the HC network for which age-related elevation of connectivity between left and right HC was found along with attenuated HC-cortical connectivity. Elevated HC connectivity at rest, which was partly accounted for by age-related decline in white matter integrity of the fornix, was associated with lower cross-sectional episodic memory performance and declining longitudinal memory performance over 20 y. Additionally, elevated HC connectivity at rest was associated with reduced HC neural recruitment and HC-cortical connectivity during active memory encoding, which suggests that strong HC connectivity restricts the degree to which the HC interacts with other brain regions during active memory processing revealed by task fMRI. Collectively, our findings suggest a model in which age-related disruption in cortico-hippocampal functional connectivity leads to a more functionally isolated HC at rest, which translates into aberrant hippocampal decoupling and deficits during mnemonic processing.

Effects of sex and gender on adaptation to space: neurosensory systems.

Sex and gender differences have long been a research topic of interest, yet few studies have explored the specific differences in neurological responses between men and women during and after spaceflight. Knowledge in this field is limited due to the significant disproportion of sexes enrolled in the astronaut corps. Research indicates that general neurological and sensory differences exist between the sexes, such as those in laterality of amygdala activity, sensitivity and discrimination in vision processing, and neuronal cell death (apoptosis) pathways. In spaceflight, sex differences may include a higher incidence of entry and space motion sickness and of post-flight vestibular instability in female as opposed to male astronauts who flew on both short- and long-duration missions. Hearing and auditory function in crewmembers shows the expected hearing threshold differences between men and women, in which female astronauts exhibit better hearing thresholds. Longitudinal observations of hearing thresholds for crewmembers yield normal age-related decrements; however, no evidence of sex-related differences from spaceflight has been observed. The impact of sex and gender differences should be studied by making spaceflight accessible and flying more women into space. Only in this way will we know if increasingly longer-duration missions cause significantly different neurophysiological responses in men and women.

Wayfinding in healthcare facilities: contributions from environmental psychology.

The ability to successfully navigate in healthcare facilities is an important goal for patients, visitors, and staff. Despite the fundamental nature of such behavior, it is not infrequent for planners to consider wayfinding only after the fact, once the building or building complex is complete. This review argues that more recognition is needed for the pivotal role of wayfinding in healthcare facilities. First, to provide context, the review presents a brief overview of the relationship between environmental psychology and healthcare facility design. Then, the core of the article covers advances in wayfinding research with an emphasis on healthcare environments, including the roles of plan configuration and manifest cues, technology, and user characteristics. Plan configuration and manifest cues, which appeared early on in wayfinding research, continue to play a role in wayfinding success and should inform design decisions. Such considerations are joined by emerging technologies (e.g., mobile applications, virtual reality, and computational models of wayfinding) as a way to both enhance our theoretical knowledge of wayfinding and advance its applications for users. Among the users discussed here are those with cognitive and/or visual challenges (e.g., Down syndrome, age-related decrements such as dementia, and limitations of vision). In addition, research on the role of cross-cultural comprehension and the effort to develop a system of universal healthcare symbols is included. The article concludes with a summary of the status of these advances and directions for future research.

The altered vestibular-evoked myogenic and whole-body postural responses in old men during standing

Age-related decrements within the sensorimotor system may lead to alterations and impairments in postural control, but a link to a vestibular mechanism is unclear. The purpose of the present study was to determine whether vestibular control of standing balance is altered with adult aging. Eight old (~77years) and eight young (~26years) men stood without aids on a commercially available force plate with their head turned to the right, arms relaxed at their sides and eyes closed while receiving stochastic vestibular stimuli (0–25Hz, root mean square amplitude=0.85mA). Surface electromyography signals were sampled from the left soleus, medial gastrocnemius and tibialis anterior. Whole-body balance, as measured by the anteroposterior forces and muscle responses, was quantified using frequency (coherence and gain functions) and time (cumulant density function) domain correlations with the vestibular stimuli. Old men exhibited a compressed frequency response of the vestibular reflex with a greater relative gain at lower frequencies for the plantar flexors and anteroposterior forces than young. In the time domain, the peak amplitude of the short latency response was 45–64% lower for the plantar flexors and anteroposterior forces (p≤0.05) in the old than young, but not for the tibialis anterior (p=0.21). The old men had a 190% and 31% larger medium latency response for only the tibialis anterior and anteroposterior forces, respectively, than young (p≤0.01). A strong correlation between the tibialis anterior and the force response was also detected (r=0.80, p<0.01). In conclusion, net vestibular-evoked muscle responses led to smaller short and larger medium latency peak amplitudes in anteroposterior forces for the old. The present results likely resulted from a compressed and lower operational frequency range of the vestibular reflexes and the activation of additional muscles (tibialis anterior) to maintain standing balance.

Fatigue-induced balance alterations in a group of Italian career and retained firefighters

Firefighters (FFs) often work in hazardous and physically-demanding environments, and injuries related to loss of balance are common among them. This study examined the postural balance of FFs with different levels of experience and training, both before and after simulated physically-demanding and fatiguing firefighting and rescue activities. Balance was assessed in two FF groups (career and “retained”, n = 13 each), on the basis of center-of-pressure (COP) time series that were acquired using a pressure platform during quiet upright stance. Several traditional COP-based measures (mean COP velocity and sway area) were derived. In addition, and to quantify the dynamical properties of postural control, complexity of the COP time series was determined using the multiscale entropy (MSE) method. Both age and the annual number of working days were higher for career FFs, though both groups had comparable levels of pre-activity balance. Post-activity changes in balance were also generally comparable between the groups, except that retained FFs exhibited a significantly higher post-activity loss of COP complexity in the medial-lateral direction. These results suggest that experience and training may serve to offset age-related decrements in postural balance, and implications for the risk of balance-related injuries during firefighting operations are discussed. Relevance to industryObjective assessment of physical capacities in firefighters may be of value to design training programs suitable to meet job demands and avoid injury.

Resistance exercise may improve spatial awareness and visual reaction in older adults.

Aerobic exercise has been shown to counteract age-related neurological decrements that are associated with cognitive and physical impairments. However, the effects of resistance exercise on cognition, reaction, and neurotrophins are largely unknown. We examined changes in spatial awareness, visual and motor reaction, and circulating brain-derived neurotrophic factor (BDNF) in response to a resistance exercise intervention in older adults (aged 70.6 ± 6.1 years). Spatial awareness was evaluated before and after training with a Neurotracker perceptual 3-dimensional object-tracking device. Peripheral, visual, motor, and physical reaction times were evaluated using a Dynavision visuomotor device. Circulating BDNF was assayed. Data were analyzed for clinical significance using magnitude-based inferences calculated from independent t-tests. Clinical interpretations of the analyses revealed that resistance exercise training was "likely beneficial" for improving spatial awareness and visual and physical reaction times. Each improved by 40.0, 14.6, and 14.0%, respectively. Circulating BDNF and motor reaction time displayed no apparent meaningful changes. Thus, resistance exercise training may be an effective means to preserve or improve spatial awareness and reaction with aging.

Aging Decreases L-Type Calcium Channel Currents and Pacemaker Firing Fidelity in Substantia Nigra Dopamine Neurons

Substantia nigra dopamine neurons are involved in behavioral processes that include cognition, reward learning, and voluntary movement. Selective deterioration of these neurons is responsible for the motor deficits associated with Parkinson's disease (PD). Aging is the leading risk factor for PD, suggesting that adaptations occurring in dopamine neurons during normal aging may predispose individuals to the development of PD. Previous studies suggest that the unique set of ion conductances that drive spontaneous, rhythmic firing of action potentials could predispose substantia nigra dopamine neurons to selective neurodegeneration. Here we show, using patch-clamp electrophysiological recordings in brain slices, that substantia nigra dopamine neurons from mice 25-30 months of age (old) have comparable membrane capacitance and input resistance to neurons from mice 2-7 months of age (young). However, neurons from old mice exhibit slower firing rates, narrower spike widths, and more variable interspike intervals compared with neurons from young mice. Dopamine neurons from old mice also exhibit smaller L-type calcium channel currents, providing a plausible mechanism that likely contributes to the changes in impulse activity. Age-related decrements in the physiological function of dopamine neurons could contribute to the decrease in voluntary movement and other dopamine-mediated behaviors observed in aging populations. Furthermore, as pharmacological antagonism of L-type calcium channels has been proposed as a potential treatment for the early stages of PD, our results could point to a limited temporal window of opportunity for this therapeutic intervention.

Skeletal muscle function deficit: a new terminology to embrace the evolving concepts of sarcopenia and age-related muscle dysfunction.

Concerns remain as to the best terminology to embrace sarcopenia's evolving conceptualization. Many of these concerns stem from the fact that age-related decrements in muscle performance associated with physical impairment are only partially explained by decreases in muscle mass and that other pathophysiologic factors contribute to age-related impairments in muscle performance. Review of literature on the evolving conceptualization of sarcopenia since its early definition in 1989 and concerns with terminology. Early definitions of sarcopenia were based solely on muscle mass in relationship to the range of muscle within a reference population. Subsequent definitions added performance criteria to muscle mass alone. The Foundation for the National Institutes of Health Sarcopenia Project identified criteria for clinically relevant low muscle strength (weakness) and low lean mass. Progress on the sarcopenia's evolving definitions has not been accompanied by recommendations on specific terminologies that address the lack of sufficient specificity from the use of an anatomic term to define a functional condition with numerous now known nonanatomic contributory factors. Skeletal Muscle Function Deficit is a broader construct that accommodates a set of diagnoses that includes both sarcopenia and other age-related muscle dysfunctions. Skeletal Muscle Function Deficit is proposed as a new terminology to embrace the evolving conceptualization of sarcopenia and other age-related muscle dysfunctions. It comprises a variety of contributory etiologies and has the potential to provide a framework for developing diagnostic categories that are useful for both clinical practice and research.

The effect of knee joint angle on plantar flexor power in young and old men

Human adult aging is associated with a loss of strength, contractile velocity and hence, power. The principal plantar flexors, consisting of the bi-articular gastrocnemeii and the mono-articular soleus, appear to be affected differently by the aging process. However, the age-related effect of knee joint angle on the torque–angular velocity relationship and power production of this functionally important muscle group is unknown. The purpose was to determine whether flexing the knee, thereby reducing the gastrocnemius contribution to plantar flexion, would exacerbate the age-related decrements in plantar flexion power, or shift the torque–angular velocity relationship differently in older compared with young men. Neuromuscular properties were recorded from 10 young (~25y) and 10 old (~78y) men with the knee extended (170°) and flexed (90°), in a randomized order. Participants performed maximal voluntary isometric contractions (MVCs), followed by maximal velocity-dependent shortening contractions at pre-set loads, ranging from 15 to 75% MVC. The young men were ~20–25% stronger, ~12% faster and ~30% more powerful than the old for both knee angles (P<0.05). In both age groups, isometric MVC torque was ~17% greater in the extended than flexed knee position, with no differences in voluntary activation (>95%). The young men produced 7–12% faster angular velocities in the extended knee position for loads ≤30% MVC, but no differences at higher loads; whereas there were no detectable differences in angular velocity between knee positions in the old across all relative loads. For both knee angles, young men produced peak power at 43.3±9.0% MVC, whereas the old men produced peak power at 54.8±7.9% MVC. These data indicate that the young, who have faster contracting muscles compared with the old, can rely more on velocity than torque for generating maximal power.

Age-Related Decrements in Heat Dissipation during Physical Activity Occur as Early as the Age of 40

Older adults typically experience greater levels of thermal strain during physical efforts in the heat compared to young individuals. While this may be related to an age-dependent reduction in whole-body sweating, no study has clearly delineated at what age this occurs. In the present study, we report direct measurements of human heat dissipation during physical activity in the heat in males ranging in age from 20–70 years. Eighty-five males performed four 15-min bouts of cycling separated by 15-min rest periods, in a calorimeter regulated to 35°C and 20% relative humidity. Direct calorimetry was used to measure total heat loss (whole-body evaporative heat loss and dry heat exchange). We also used indirect calorimetry as a continuous measure of metabolic heat production. Body heat storage was calculated as the temporal summation of heat production and total heat loss over the experimental session. Whole-body sweat rate (WBSR) was calculated from measurements of evaporative heat loss. Males were divided into five age categories for the analysis of WBSR and body heat storage: 20–31 years (n = 18), 40–44 years (n = 15), 45–49 years (n = 15), 50–55 years (n = 21) and 56–70 years (n = 16). Relative to young males, WBSR was reduced in males aged 56–70 during each exercise (all P<0.05), in males aged 50–55 during the second (P = 0.031) and third exercises (P = 0.028) and in males aged 45–49 during the final exercise bout (P = 0.046). Although not significantly different, 40–44 years old males also had a lower rate of heat loss compared to younger males. Over the sum of two hours, the change in body heat content was greater in males 40–70 years compared to young males (all P<0.05). Our findings suggest that middle-aged and older adults have impairments in heat dissipation when doing physical activity in the heat, thus possibly increasing their risk of heat-related illness under such conditions.

Nonuniform, age-related decrements in regional sweating and skin blood flow

Aging is associated with attenuated thermoregulatory function that varies regionally over the body. Decrements in vasodilation and sweating are well documented with age, yet limited data are available concerning the regional relation between these responses. We aimed to examine age-related alterations in the relation between regional sweating (RSR) and skin blood flow (SkBF) to thermal and pharmacological stimuli. Four microdialysis fibers were inserted in the ventral forearm, abdomen, thigh, and lower back of eight healthy aged subjects (64 ± 7 yr) and nine young (23 ± 3 yr) during 1) ACh dose response (1 × 10(-7) to 0.1 M, mean skin temperature 34°C) and 2) passive whole body heating to Δ1°C rise in oral temperature (Tor). RSR and SkBF were measured over each microdialysis membrane using ventilated capsules and laser-Doppler flowmetry. Maximal SkBF was measured at the end of both protocols (50 mM SNP). Regional sweating thresholds and RSR were attenuated in aged vs. young at all sites (P < 0.0001) during whole body heating. Vasodilation thresholds were similar between groups (P > 0.05). Attenuated SkBF were observed at the arm and back in the aged, representing 56 and 82% of those in the young at these sites, respectively (0.5 ΔTor). During ACh perfusion, SkBF (P = 0.137) and RSR were similar between groups (P = 0.326). Together these findings suggest regional age-related decrements in heat-activated sweat gland function but not cholinergic sensitivity. Functional consequences of such thermoregulatory impairment include the compromised ability of older individuals to defend core temperature during heat exposure and a subsequently greater susceptibility to heat-related illness and injury.

The rise of the “innosumer”—Rethinking older technology users

Abstract Demographic aging is among the most striking challenges industrialized economies face; it will lead to profound changes in consumption structures. How these changes will affect innovation, however, is thus far not well understood. In this paper we make a first step towards closing this gap and establish the challenges associated with demographic aging on the map of innovation scholars. We revisit empirical results of our research into the modes of thinking that underlie design processes targeted at older persons. These modes are limited in two ways—they concentrate on older persons as being characterized by generic, age-related decrements, and they frame older technology users as passive recipients of technology. Current design practices for older persons, therefore, imply a threefold risk. They are likely to generate technology that is unattractive for older consumers, that provides limited cues for meaningful activity, and that suppresses the co-creational inputs of older persons to innovation. To rectify this, we propose a complementary perspective on the relationship between technology and aging that focuses on older persons as active consumers of technology. We discuss implications for further research on technology and aging that revolves around a new concept that we call “innosumer”.

The nature and correlates of self-esteem trajectories in late life.

Is it possible to maintain a positive perspective on the self into very old age? Empirical research so far is rather inconclusive, with some studies reporting substantial declines in self-esteem late in life, whereas others report relative stability into old age. In this article, we examine long-term change trajectories in self-esteem in old age and very old age and link them to key correlates in the health, cognitive, self-regulatory, and social domains. To do so, we estimated growth curve models over chronological age and time-to-death using 18-year longitudinal data from the Australian Longitudinal Study of Ageing (N = 1,215; age 65-103 years at first occasion; M = 78.8 years, SD = 5.9; women: 45% of sample). Results revealed that self-esteem was, on average, fairly stable with minor declines only emerging in advanced ages and at the very end of life. Examination of the vast between-person differences revealed that lower cognitive abilities and lower perceived control independently related to lower self-esteem. Also, lower cognitive abilities were associated with steeper age-related and mortality-related self-esteem decrements. In our discussion, we consider a variety of challenges that potentially shape self-esteem late in life and highlight the need for more mechanism-oriented research to better understand the pathways underlying stability and change in self-esteem.

Age-related changes of rhythmic ability in musically trained and untrained individuals

The ability to discriminate and reproduce a rhythmic sequence of sounds is considered to reflect a combination of maturation and experience. This study aimed to assess age-related decrements in reproduction of rhythmic patterns in musically untrained adults (range 25–54 years), young-old (range 60–69 years), and old (range 70–79 years) individuals, and co-aged old (range 60–79 years) musicians. Participants were required to reproduce on an electronic pad three rhythmic sequences differing in time signature (meter), inter-event ratio and tempo. Differences between the standard and its reproductions in number of events, total duration and ratio among rhythmic events were calculated. All variables showed that rhythmic ability is negatively affected by aging, with lengthening errors of total duration increasing markedly after 60 years of age. However, reproductions were positively affected by expertise. The results suggest that training can effectively counteract decremental trend in rhythmic reproduction ability that emerges with aging.