Simulated aged performance on the embedded figures test

According to Labouvie-Vief (1985) the predominant explanatory mechanism for performance decline among the elderly incorporates a regression-oriented view of cognitive development: The present study tested the hypothesis that age-related performance decline may be explained by the quantitative changes in lower-level visual functions, such as those due to preretinal aging, which preclude the expression of intact cognitive (qualitative) processes. Thirty undergraduate female volunteers (18 to 25 years) viewed the Embedded Figures Test (EFT) under three conditions: no-filter viewing, .6 neutral-density filter viewing, and simulated-aged (yellow-filter plus .5 neutral-density filter) viewing. A one-way ANOVA revealed significant viewing condition effects for the number of items solved, the number of errors, and time-to-solution. Significant linear trends were found for levels of luminous transmittance. Results supported the hypothesis that preretinal aging appears to degrade EFT performance.     

Effects of aging on perceptual organization: efficacy of stimulus features

Perceptual organization represents an intermediate level of visual processing, subordinate to higher-order processes such as object recognition. Previous studies of perceptual organization in aging are inconclusive, varying in the cognitive capacities measured and the nature of the stimulus. To determine characteristics of perceptual organization in aging, young and elderly participants discriminated patterns organized by basic visual components: line-orientation, color, flicker, or motion. Psychophysical measurements determined organization thresholds and processing times. Age-related impairment occurred with line-orientation and flicker, but not color and motion. These results indicate that perceptual organization capacities in aging depend on the stimulus feature upon which organization is based.     

Aging and similarity grouping in visual search

It has been argued that principles of perceptual organization play an important role in the representation of a visual stimulus and that elderly adults may be deficient in perceptual unit formation. The present study examined the extent to which the Gestalt principles of grouping by proximity and similarity predicted the formation of large perceptual units that could affect performance in a visual search task. The verbal reaction time to determine the presence or absence of a target letter in arrays of 1, 5, or 9 elements was determined for young (20 years) and elderly (69 years) adults. Both age groups could take advantage of the organization implied by Gestalt principles in finding a target in the context of a small implied group. The elderly adults, however, were not able to organize a single perceptual unit composed of eight elements. Thus, although the visual search performance of the age groups was similar, the elderly adults did yield evidence of a perceptual organization deficit.     

Implicit and explicit measures of memory for perceptual information in young adults,healthy older adults,and patients with Alzheimer's disease

In this study, we examined how implicit and explicit memory for perceptual information (modality and voice) and lexical information varied across three subject groups: healthy young adults, healthy older adults, and age-matched older adults with dementia of the Alzheimer's type (DAT). These groups exhibited cross-modality (abstract) priming of the same magnitude. However, young adults produced greater modality- and voice-specific priming than the other two groups, whose performance was equivalent, suggesting that aging, but not DAT, reduced form-specific priming. Young adults demonstrated better recognition memory than healthy older adults, who in turn exhibited better recognition memory than older adults with DAT. In young adults, recognition memory was also sensitive to perceptual information. These findings indicate that aging can affect implicit memory for perceptual information, whereas DAT magnifies the effect of aging on explicit memory.     

The role of bacterial adherence in urinary tract infections in elderly adults

In an attempt to clarify host factors responsible for the acquisition of bacteriuria in elderly adults, bacterial adherence to uroepithelial cells obtained from 83 elderly participants and 40 young controls was studied. Seven uropathogenic strains of E. coli expressing different adhesions were used. Bacteria adhered significantly better to cells of young women than young men (p less than .0001) and elderly women than elderly men (p less than .03). The greatest adherence was in young women and the least in young men. In women without bacteriuria, aging was not associated with increased susceptibility to bacterial attachment. Moreover, there was no increase in the adherence of E. coil strains to uroepithelial cells of bacteriuric elderly women in comparison to abacteriuric elderly women. In men, however, aging was associated with increased bacterial adherence (p less than .02). Susceptibility to bacterial adherence does not appear to be responsible for the increased frequency of E. coli bacteriuria in elderly women but may be a permissive factor in elderly men.     

Age-related changes in the morphology and deformational behavior of knee joint cartilage.

OBJECTIVE: Alterations of cartilage morphology and mechanical properties occur in osteoarthritis, but it is unclear whether similar changes also take place physiologically during aging, in the absence of disease. In this in vivo study, we tested the hypothesis that thinning of knee joint cartilage occurs with aging and that elderly subjects display a different amount of cartilage deformation than do young subjects. METHODS: We evaluated 30 asymptomatic subjects ages 50-78 years. Morphologic parameters for the knee cartilage (mean and maximum thickness, surface area) were computed from magnetic resonance imaging data. Results were compared with those in 95 young asymptomatic subjects ages 20-30 years. Deformation of the patellar cartilage was determined after the subjects performed 30 knee bends. RESULTS: There was a significant reduction of patellar cartilage thickness in elderly women (-12%; P < 0.05), but not in elderly men (-6%). Femoral cartilage was significantly thinner in both sexes (-21% in women, -13% in men; P < 0.01), whereas tibial cartilage thickness displayed only nonsignificant trends (-10% in women, -7% in men). Patellar cartilage deformation was -2.6% in elderly women and -2.2% in elderly men. These values were significantly lower (P < 0.05) than those in young subjects. CONCLUSION: We confirmed the hypothesis that knee cartilage becomes thinner during aging, in the absence of cartilage disease, but that the amount of reduction differs between sexes and between compartments of the knee joint. We show that under in vivo loading conditions, elderly subjects display a lower level of cartilage deformation than do healthy young subjects.     

Aging and the locus of the global precedence effect: a short review and new empirical data

Precedence of the global over the local level in visual perception is well established by the use of compound, or hierarchical, stimuli. However, (a) virtually nothing is known concerning the fate of global precedence with normal aging, and (b) there is still a debate about the early versus late perceptual locus of the effect. The present study was planned to investigate both topics. Two experiments are reported where young adult and elderly subjects were enrolled for the recognition of compound letters either at the global or at the local level. In order to recruit late perceptual processes, the case of the letters varied in such a way that subjects had to activate graphemic codes to take their decision. It appeared that the global precedence effect was preserved. This observation shows an early perceptual source of the global precedence effect, which is then transferred to later stages of information processing. Age did not affect the global precedence phenomenon.     

Aging and the Locus of the Global Precedence Effect: A Short Review and New Empirical Data

Precedence of the global over the local level in visual perception is well established by the use of compound, or hierarchical, stimuli. However, (a) virtually nothing is known concerning the fate of global precedence with normal aging, and (b) there is still a debate about the early versus late perceptual locus of the effect. The present study was planned to investigate both topics. Two experiments are reported where young adult and elderly subjects were enrolled for the recognition of compound letters either at the global or at the local level. In order to recruit late perceptual processes, the case of the letters varied in such a way that subjects had to activate graphemic codes to take their decision. It appeared that the global precedence effect was preserved. This observation shows an early perceptual source of the global precedence effect, which is then transferred to later stages of information processing. Age did not affect the global precedence phenomenon.     

Progressive mechanical ventilatory constraints with aging.

To investigate the progressive nature of mechanical ventilatory constraints with aging, we studied 20 young (age 39 +/- 3 yr), 14 senior (70 +/- 2 yr), and 11 elderly (88 +/- 2 yr) men and women during exercise. All subjects had normal pulmonary function and performed graded cycle ergometry to exhaustion. Minute ventilation (V E), lung volume, and expiratory airflow limitation (EAFL) were measured during each 1-min increment in work rate. Data were analyzed by two-way analysis of variance (ANOVA; age x gender) at rest, ventilatory threshold (VTh), and peak exercise. If an interaction was present, each gender was analyzed with a one-way ANOVA. Aging resulted in an increased V E for a given submaximal work rate, although V E during peak exercise was lowest in the elderly group (p < 0.01). End-expiratory lung volume (EELV, % of TLC) in men increased progressively with age and all groups were different at VTh (p < 0.01) and peak exercise (p < 0.01). In women, EELV (% of TLC) also increased with aging, the senior and elderly subjects had a greater EELV at VTh (p < 0.01) and peak exercise (p < 0.01) than the young group. Additionally, the normal decrease in EELV during the early stages of exercise was not observed in elderly subjects. End-inspiratory lung volume (EILV) also progressively increased with aging; senior and elderly subjects had a higher EILV at rest (p < 0.05), VTh (p < 0.01), and peak exercise (p < 0.01) than young subjects. EAFL (% of VT) increased with aging; elderly subjects experienced greater EAFL at rest (p < 0.05), VTh (p < 0.01), and peak exercise (p < 0.01) than both young and senior subjects. We conclude that mechanical ventilatory constraints are progressive with aging, elderly subjects demonstrating marked mechanical ventilatory constraints during exercise. The impact of these constraints on exercise tolerance cannot be determined from this investigation and remains unclear.     

Perceptual and motor inhibitory abilities in normal aging and Alzheimer disease (AD): a preliminary study

Deficits in inhibitory abilities are frequently observed in normal aging and AD. However, few studies have explored the generality of these deficits in a single group of participants. A battery of tasks assessing perceptual and motor inhibitory functioning was administered to young and older healthy participants (Study 1), as well as to mild Alzheimer patients (Study 2). Results did not agree with a selective impairment of motor or perceptual inhibition in either AD or normal aging but rather suggest that a decrease in cognitive resources available in working memory could explain inhibitory performance both in normal aging and AD.     

Aging-related growth hormone (GH) decrease is a selective hypothalamic GH-releasing hormone pulse amplitude mediated phenomenon

BACKGROUND: Aging is accompanied by declining growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels. The neuroendocrine mechanisms of this decline have been studied previously, but the interpretation of the data was confounded by the imprecision in GH measurements and by the intervening variables of altered body composition and decreased gonadal steroid milieu in the elderly subjects of both sexes. METHODS: To study the contribution of aging per se, we evaluated discrete parameters of GH pulsatility in young (n = 8 women, n = 8 men) and elderly (n = 11 women, in 10 men) subjects closely matched for body mass index. Blood samples for GH were obtained every 10 minutes for 24 hours. Plasma GH was measured by a sensitive chemiluminescent assay. GH pulsatility was assessed using cluster analysis. RESULTS: The elderly subjects had plasma IGF-I levels and integrated GH concentrations that were 32% to -56% of their sex-matched younger counterparts. The age-associated attenuation in GH was due to a decrease in GH pulse amplitude, whereas pulse frequency and nadir levels were unchanged. The majority of the young subjects (81%) reached their peak GH during the "lights off" period, whereas the majority of the elderly subjects (62%) peaked during the "lights on" period (p = .01). CONCLUSIONS: We conclude that aging in both sexes is accompanied by profound decreases in GH output and in plasma IGF-I concentrations. This effect is separate from the alterations in body mass index that accompany the normal aging process. Attenuation of GH output associated with aging is related solely to the lower GH and, by inference, GH-releasing hormone (GHRH) pulse amplitude.     

Modified essential frailty toolset to determine outcomes following transcatheter aortic valve replacement

BackgroundSeveral predictors are available to guide patient selection for transcatheter aortic valve replacement (TAVR) to achieve better outcomes, and the essential frailty toolset (EFT) has been reported as one of those predictors. This study investigated whether a modified EFT could independently predict all-cause mortality following TAVR.MethodsThe study population comprised 176 consecutive patients with severe aortic stenosis whose frailty was assessed with a modified EFT prior to TAVR at the Sakakibara Heart Institute between 2013 and 2018. The primary endpoint was all-cause mortality following TAVR. To understand the association between the modified EFT and all-cause mortality, multivariate Cox regression analysis was performed. In addition, to understand its predictive performance, we conducted a receiver operating characteristic (ROC) analysis.ResultsPatients were elderly, relatively frail, and were likely to have significant heart failure symptoms. By the modified EFT definition, 40 patients (22.7%) were considered frail. With a median follow up of 1145 days, all-cause mortality at 1, 2, and 3 years was 6.2%, 10.2%, and 18.3%, respectively. Patients assessed as more frail on the clinical frailty scale had higher modified EFT scores. In ROC analysis, the area under the curve for predicting all-cause mortality at 1, 2, and 3 years was 0.79 [95% confidence interval (CI) 0.68?0.90]; 0.74 (95% CI 0.62?0.84); and 0.67 (95% CI 0.56?0.79), respectively, with the best cut-off modified EFT score of 1/2.ConclusionsThe modified EFT score was independently associated with all-cause mortality and had excellent predictive performance for all-cause mortality at 1 year.     

Contextual effects upon text memory for young,aged-normal,and aged memory-impaired individuals

The purpose of the study was to assess contextual effects upon text memory for young, aged-normal, and aged memory-impaired individuals. Subjects read short passages which differed in their contextual relatedness to target sentences, and then recalled those target sentences. It was found that large differences distinguished the performance of the young from the elderly on the free recall task; that cueing aided the performance of the young and the elderly-normal more than the aged-impaired; and lastly, that no differences were found in recognition performance between young and aged normals whereas the performance of the aged-impaireds was significantly poorer than either the young or the aged-normal group. The results were interpreted in light of two hypothetical mechanisms; the first is tabled “normal” aging and the second, “pathological” aging.     

Contextual effects upon text memory for young, aged-normal, and aged memory-impaired individuals

The purpose of the study was to assess contextual effects upon text memory for young, aged-normal, and aged memory-impaired individuals. Subjects read short passages which differed in their contextual relatedness to target sentences, and then recalled those target sentences. It was found that large differences distinguished the performance of the young from the elderly on the free recall task; that cueing aided the performance of the young and the elderly-normal more than the aged-impaired; and lastly, that no differences were found in recognition performance between young and aged normals whereas the performance of the aged-impaireds was significantly poorer than either the young or the aged-normal group. The results were interpreted in light of two hypothetical mechanisms; the first is labeled "normal" aging and the second, "pathological" aging.     

Influence of adiposity in the blunted whole-body protein anabolic response to insulin with aging

BACKGROUND: Although insulin resistance of glucose is often reported with aging, that of protein metabolism is still debated. We tested if the insulin sensitivity of protein metabolism parallels that of glucose and is altered with aging. METHODS: Whole-body (13)C-leucine and (3)H-glucose kinetics were measured in the postabsorptive state and during an hyperinsulinemic, euglycemic, isoaminoacidemic clamp in 12 young men (age: 27 +/- 1 years; body mass index [BMI]: 23 +/- 1 kg/m(2)), 11 young women (age: 25 +/- 1 years; BMI: 21 +/- 1 kg/m(2)), 9 elderly men (age: 70 +/- 1 years; BMI: 26 +/- 1 kg/m(2)), and 10 elderly women (age: 69 +/- 2 years; BMI: 23 +/- 1 kg/m(2)). RESULTS: Postabsorptive leucine flux rates adjusted for fat-free mass (FFM) were not different between elderly and young participants. During the clamp, leucine flux and protein synthesis rates increased less in the elderly participants, and protein breakdown decreased equally. Thus, the net anabolic (protein balance) response to hyperinsulinemia was lower in elderly versus young participants (p =.007) and was highly correlated with the clamp glucose rate of disposal (r = 0.671, p <.001), indicating insulin resistance of protein concurrent with that of glucose. From regression analysis, FFM explained 73% of the variance in the anabolic response. Age explained an additional 3%, but was accounted for by markers of adiposity. FFM and percent body fat collectively explained 79% of the variance. CONCLUSION: Both reduction in absolute FFM and increased adiposity, intrinsic to the aging process, are associated with an altered anabolic action of insulin in stimulating protein synthesis. This alteration may contribute to the progressive muscle loss with aging.     

The effects of stimulant drugs on information processing in elderly adults

The effects of stimulant drug on information processing in elderly adults was studied. In Experiment 1, the effect of methylphenidate (MP) was examined in 8 young and 8 elderly women using a task (SERS) in which stimulus and response complexities were varied. MP speeded processing in the young but not in the elderly women. A second experiment was then conducted to isolate the age-stimulant effects. In Experiment 2, the effects of MP and 10 mg of d-amphetamine (DAMP) were studied in 12 young and 12 elderly men on different types of information processing. Stimulants changed performance on a continuous performance task in both groups. Both stimulants speeded processing on SERS in young, but not in elderly men. MP, however, speeded processing in both groups on a response processing task. The findings suggest that stimulants act on response processing and there appear to be several such processes. Some of these stages decline with age whereas others do not.     

The effect of age and gender on cytokine production by human peripheral blood mononuclear cells and markers of bone metabolism

BACKGROUND. Aging has been associated with various alterations of immune functions, the musculoskeletal system and a decline of sex hormone levels. Estradiol has a central role in the regulation of bone turnover and also modulates the production of cytokines such as interleukin-1 and -6 and tumor necrosis factor-alpha. We therefore studied the effect of age and gender on cytokine production by mononuclear cells and markers of bone metabolism. METHODS. Peripheral blood mononuclear cells were isolated from young and elderly subjects; intracellular detection of cytokine production after stimulation with ionomycine and PMA (T cells) or LPS (monocytes) was performed by four color flow cytometry. Sex hormone levels and markers of bone metabolism were measured by RIA or ELISA. RESULTS. When we compared elderly to young women we found an increased proportion of T cells that were positive for interferon-gamma, interleukin-2, -4, -10 and -13. Also the percentage of cells producing interleukin-4 or interferon-gamma within the CD8(+) population was higher in the group of elderly women. In contrast, proportionally fewer monocytes of elderly women were positive for tumor necrosis factor-alpha or interleukin-6 than those of young women. In elderly men a higher percentage of T cells produced interleukin-2, -4 and -13. In the group of aged men we found a higher frequency of cells that produced interleukin-4 within the CD4(+) or CD8(+) population. Moreover, within monocytes of elderly men we found an increased percentage of cells positive for both interleukin-1beta and tumor necrosis factor-alpha. The data on markers of bone metabolism indicated an increase of bone turnover in old age. CONCLUSION. Our data demonstrate that aging is associated with significant alterations of bone metabolism and cytokine production by T cells and monocytes. For particular cytokines (interferon-gamma and interleukin-10 in T cells, interleukin-6 and tumor necrosis factor-alpha in monocytes) these changes are gender specific.     

The fate of global precedence with age

The literature is virtually devoid of studies examining the effect of aging on the "global precedence" effect (Navon, D. [1977]. Cognitive Psychology, 9, 353-383). In this paradigm, global letters formed with local letters are shown, and the subject has to recognize either the local or the global letters. The relation between the global and the local letters is either congruent, neutral, or conflicting. Five experiments are reported, with five sets of 16 young and five sets of 16 elderly, healthy, adult subjects. The global precedence effect was observed in both age groups in the basic perceptual experiment as designed by Navon (Experiment 1). In addition, young and elderly subjects were able to process separately the global and the local shapes when attention was not directed towards a specific level (Experiment 1a). However, subpopulations emerged, especially in the elderly, depending on their ability to "resist" to the interference of the global shape upon the processing of the local form. This could support the few indirect published data suggesting that global precedence tends to diminish or to disappear with age. In experiments 2 and 2a, subjects were retained only if they did process the local level better than at random. Global precedence was confirmed in both young and elderly subjects. Again, elderly subjects manifested an increased sensitivity to interference. Moreover, a general effect of age remained, even in the control (neutral) conditions, suggesting difficulties of encoding in elderly. Therefore, in Experiment 3, encoding conditions of both age groups were equated by increasing exposure duration of the material for elderly. Subjects of Experiment 3 were also submitted to a Stroop test, to verify whether the increased sensitivity to interference in the elderly was specific to the "Navon task" or the expression of a general effect of aging on inhibition mechanisms. The global precedence phenomenon was observed in young and elderly subjects, with no sign of an effect of age under these conditions; in elderly, furthermore, the interference effect did not appear to result from a general aspecific deficit of inhibition mechanisms. It thus appears that the global precedence phenomenon resists well the effects of aging, but that subpopulations of elderly subjects should be considered in future studies.     

Growth hormone responses to low-dose physostigmine in elderly vs. young women and men

BACKGROUND: Growth hormone (GH) secretion is a sensitive measure of CNS cholinergic neurotransmission, and GH decreases considerably with age. Cholinesterase inhibitors, which increase acetylcholine concentrations, have been used in elderly subjects to investigate the neuroendocrine effects of aging and Alzheimer's disease. However, there have been only a few studies of a potential sex difference in GH responses to cholinesterase inhibitors in elderly subjects, with mixed results. OBJECTIVE: We therefore administered low-dose physostigmine (PHYSO), a cholinesterase inhibitor, to normal, non-hormone-replaced, elderly women and men, to ascertain a potential sex difference in GH response. We hypothesized: (1) elderly women and men would have similar hormone responses, because of relatively low circulating estrogen in the women, and (2) the elderly women would have significantly lower baseline GH and GH responses to cholinergic challenge than the young women we studied previously. METHODS: Normal elderly women and men > or =65 years of age meeting stringent inclusion and exclusion criteria were studied on three test days, 4-7 days apart, by serial blood sampling for several hours for baseline GH, followed by administration of low-dose PHYSO (first and third days) or saline (second day) at 18:00 h. Frequent blood sampling was continued for several hours. Plasma GH and hypothalamo-pituitary-adrenal cortical hormones were measured in each sample. RESULTS: PHYSO administration produced no side effects in about half the elderly subjects and mild side effects in the other half, with no significant female-male differences and no significant relationship between the presence or absence of side effects and GH response. PHYSO significantly increased GH compared to saline, to a similar degree in the elderly women and men. The elderly women had a significantly greater GH response to PHYSO than did the young women, whereas GH responses were similar in the elderly and young men. CONCLUSIONS: These results indicate similar GH responses to low-dose PHYSO in elderly women compared to elderly men, and a significantly greater GH response in elderly women compared to young women. A likely mechanism is increased sensitivity of central cholinergic systems that inhibit somatostatin and/or enhance GHRH release from the hypothalamus.     

Circadian rhythm of serum immunoreactive inhibin in young and elderly men

Serum testosterone (T) levels and inhibin levels decline with normal male aging. In addition, in young men, serum T levels demonstrate a circadian variation that is blunted or lost with normal aging. The purpose of this study was to determine whether serum immunoreactive inhibin levels also demonstrate a circadian variation in young men and if normal aging has an effect on the 24 hr serum inhibin pattern. Hourly blood samples were obtained for 24 hr from 7 young (age 25-35 yr) and 7 elderly (age 65-72 yr) healthy men. Serum inhibin and testosterone levels were measured by RIA. Similar to T, serum inhibin levels demonstrated a circadian pattern in young men. Elderly men also demonstrated a circadian rhythm in serum inhibin, with an average amplitude that was not significantly different from that found in young men, despite the fact that the average 24-hr inhibin level in the elderly men was significantly lower than in the young men. These results demonstrate that immunoreactive inhibin, like T, displays a circadian rhythm in the serum of adult men and the inhibin biorhythm is maintained in elderly men.