线粒体与认知老化

目前,心理学、生物学、社会学等多个学科都在关注认知老化。文章从生物学的角度,论述了线粒体和认知老化的关系;介绍了线粒体在数量、分布及其能量供应,Ca2+浓度的维持,引发神经细胞凋亡,及线粒体基因等几个方面对认知老化产生的影响;描述了老化过程中线粒体功能失常引起的认知障碍;从而,为后人对认知老化产生机制的深入研究提供一定的理论依据。     

Effects of aging and divided attention on memory for items and their contexts

It is commonly found that memory for context declines disproportionately with aging, arguably due to a general age-related deficit in associative memory processes. One possible mechanism for such deficits is an age-related reduction in available processing resources. In two experiments we compared the effects of aging to the effects of division of attention in younger adults on memory for items and context. Using a technique proposed by Craik (1989), linear functions relating memory performance for items and their contexts were derived for a Young Full Attention group, a Young Divided Attention group, and an Older Adult group. Results suggested that the Old group showed an additional deficit in associative memory that was not mimicked by divided attention. It is speculated that both divided attention and aging are associated with a loss of available processing resources that may reflect inefficient frontal lobe functioning, whereas the additional age-related decrement in associative memory may reflect inefficient processing in medial-temporal regions.     

An Intricate Dance: Life Experience,Multisystem Resiliency,and Rate of Telomere Decline Throughout the Lifespan

Accumulation of life stressors predicts accelerated development and progression of diseases of aging. Telomere length, the DNA‐based biomarker indicating cellular aging, is a mechanism of disease development, and is shortened in a dose response fashion by duration and severity of life stressor exposures. Telomere length captures the interplay between genetics, life experiences and psychosocial and behavioral factors. Over the past several years, psychological stress resilience, healthy lifestyle factors, and social connections have been associated with longer telomere length and it appears that these factors can protect individuals from stress‐induced telomere shortening. In the current review, we highlight these findings, and illustrate that combining these ‘multisystem resiliency’ factors may strengthen our understanding of aging, as these powerful factors are often neglected in studies of aging. In naturalistic studies, the effects of chronic stress exposure on biological pathways are rarely main effects, but rather a complex interplay between adversity and resiliency factors. We suggest that chronic stress effects can be best understood by directly testing if the deleterious effects of stress on biological aging processes, in this case the cell allostasis measure of telomere shortening, are mitigated in individuals with high levels of multisystem resiliency. Without attending to such interactions, stress effects are often masked and missed. Taking account of the cluster of positive buffering factors that operate across the lifespan will take us a step further in understanding healthy aging. While these ideas are applied to the telomere length literature for illustration, the concept of multisystem resiliency might apply to aging broadly, from cellular to systemic health.     

Explicitly modeling the effects of aging on response time

Research into the effects of aging on response time has focused on Brinley plots. Brinley plots are constructed by plotting mean response times for older subjects against those for young subjects for a set of experimental conditions. The typical result is a straight line with a slope greater than 1 and a negative intercept. This linear function has been interpreted as showing that aging leads to a general slowing of cognitive processes. In this article, we show that the slope of the Brinley plot is actually a measure of the relative standard deviations of older versus young subjects’ response times; it is not a measure of general slowing. We examine current models of the effects of aging on mean response time and show how they might be reinterpreted. We also show how a more comprehensive model, Ratcliff’s diffusion model (1978), can account for Brinley plot regularities and, at the same time, provide an account of accuracy rates, the shapes of response time distributions, and the relative speeds of error and correct response times, aspects of the data about which models designed to account for Brinley plots are mute. We conclude by endorsing a research approach that applies explicit models to response time data in aging in order to use the parameters of the model to interpret the effects of aging.     

Does Estrogen Protect Against Cognitive Aging in Women?

ABSTRACT— Although there is evidence from randomized controlled trials that estrogen therapy protects against aspects of cognitive decline that occur with normal aging in women, findings from the Women's Health Initiative Memory Study and from some cross-sectional and longitudinal studies failed to find neuroprotective effects of estrogen in older women. There is growing empirical support for the critical-period hypothesis, formulated in the attempt to resolve these discrepancies. It holds that estrogen therapy has protective effects on verbal memory and on working memory only when it is initiated closely in time to menopause, whereas starting treatment many years following menopause does not protect and may even be harmful. Supporting evidence for this hypothesis from basic neuroscience and from animal and human studies is evaluated for its ability to explain the inconsistencies and to describe the conditions under which estrogen may protect cognitive function in aging women.     

Effects of hormone replacement therapy and aging on cognition: evidence for executive dysfunction

The present study was designed to explore whether the frontal lobe hypothesis of cognitive aging may be extended to describe the cognitive effects associated with estrogen use in postmenopausal women. Postmenopausal estrogen-only users, estrogen + progesterone users, and non-users (60-80 years old), as well as young, regularly cycling women (18-30 years old) completed an item and source memory task. Since source memory is thought to rely more on executive processes than item memory, we hypothesized that aging and estrogen effects would be greater for source memory than for item memory. Neuropsychological tests explored whether the effects of aging and estrogen use were revealed on other tests of frontal lobe function. Results from the experimental task revealed greater aging and estrogen effects for source memory than for item memory, and neuropsychological results revealed aging and estrogen effects on a subset of tests of executive function. Women on estrogen + progesterone therapy did not outperform non-users, suggesting that the addition of progesterone to hormone therapy may mitigate the benefits induced by estrogen use alone. Overall, findings support the hypothesis that estrogen use may temper age-related cognitive decline by helping to maintain functions subserved by the frontal lobes.     

Effects of Hormone Replacement Therapy and Aging on Cognition: Evidence for Executive Dysfunction

ABSTRACT

The present study was designed to explore whether the frontal lobe hypothesis of cognitive aging may be extended to describe the cognitive effects associated with estrogen use in postmenopausal women. Postmenopausal estrogen-only users, estrogen + progesterone users, and non-users (60–80 years old), as well as young, regularly cycling women (18–30 years old) completed an item and source memory task. Since source memory is thought to rely more on executive processes than item memory, we hypothesized that aging and estrogen effects would be greater for source memory than for item memory. Neuropsychological tests explored whether the effects of aging and estrogen use were revealed on other tests of frontal lobe function. Results from the experimental task revealed greater aging and estrogen effects for source memory than for item memory, and neuropsychological results revealed aging and estrogen effects on a subset of tests of executive function. Women on estrogen + progesterone therapy did not outperform non-users, suggesting that the addition of progesterone to hormone therapy may mitigate the benefits induced by estrogen use alone. Overall, findings support the hypothesis that estrogen use may temper age-related cognitive decline by helping to maintain functions subserved by the frontal lobes.     

The Neuropsychology of HIV/AIDS in Older Adults

Highly active antiretroviral therapy is allowing increasing numbers of adults to age with HIV. The neuropsychological effects of aging with HIV are reviewed through three types of studies. First, the separate effects of HIV and aging on cognition are examined in studies that compare younger adults with HIV with neurologically normal older adults. Second, studies examine the impact of aging within samples of adults with HIV only. Third, providing the most critical evidence, are studies that assess cognition in younger and older adults with HIV relative to younger and older adults without HIV. In general research findings are inconclusive. Large individual differences among older adults with HIV as well as co-factors (APOE4 and detectable viral load) may account for inconsistent findings in the literature. A subgroup of older adults with HIV may be at greater risk for cognitive impairment, especially in attention functioning.     

Alcoholism, aging, and functional cerebral asymmetries

Reviews research concerning the possible relationship between cognitive decline and abnormal hemispheric asymmetries in alcoholic and aging individuals. Because the deteriorative effects of alcoholism on the central nervous system have suggested greater visuospatial than language-related functional impairments, numerous investigators had hypothesized that right-hemisphere integrity may be selectively disrupted (rather than the left hemisphere). Furthermore, performance on diverse perceptual and cognitive tests used to measure right-hemisphere functions in alcoholics had been observed to decline with normal chronological aging as well, thereby raising the possibility that certain neuropsychological deficits associated with alcoholism (presumably related to right-hemispheric decline) are identical to those associated with aging. However, an extensive review of empirical research findings on cerebral asymmetries both in alcoholics and in aging individuals suggested that their patterns of functional laterality are similar to those of normal controls.     

Effects of aging on whole body and segmental control while obstacle crossing under impaired sensory conditions

The ability to safely negotiate obstacles is an important component of independent mobility, requiring adaptive locomotor responses to maintain dynamic balance. This study examined the effects of aging and visual–vestibular interactions on whole-body and segmental control during obstacle crossing. Twelve young and 15 older adults walked along a straight pathway and stepped over one obstacle placed in their path. The task was completed under 4 conditions which included intact or blurred vision, and intact or perturbed vestibular information using galvanic vestibular stimulation (GVS). Global task performance significantly increased under suboptimal vision conditions. Vision also significantly influenced medial–lateral center of mass displacement, irrespective of age and GVS. Older adults demonstrated significantly greater trunk pitch and head roll angles under suboptimal vision conditions. Similar to whole-body control, no GVS effect was found for any measures of segmental control. The results indicate a significant reliance on visual but not vestibular information for locomotor control during obstacle crossing. The lack of differences in GVS effects suggests that vestibular information is not up-regulated for obstacle avoidance. This is not differentially affected by aging. In older adults, insufficient visual input appears to affect ability to minimize anterior–posterior trunk movement despite a slower obstacle crossing time and walking speed. Combined with larger medial–lateral deviation of the body COM with insufficient visual information, the older adults may be at a greater risk for imbalance or inability to recover from a possible trip when stepping over an obstacle.     

Chapter 8: “Always Green and Full of Sap”: Facilitating Wholeness in Aging

SUMMARY

Wholeness in aging is difficult to define, especially in the face of physical disability or catastrophic illness. How one meets the challenges of aging depends upon numerous physical, emotional, and spiritual factors. Rehabilitation may play an important role in restoring wholeness to those with physical disabilities. Likewise, a physical fitness program may lessen some of the effects of aging, helping the older person maintain a higher quality of life. The lived theologies of the older patients and their caregivers also interact, providing an important ground of connection in rediscovery of wholeness as well. Ultimately, our most important role as healthcare providers is to help our older patients regain and maintain this multidimensional wholeness even in times of physical challenge.     

Progressive age-related changes in the attentional blink paradigm

Previous studies on aging and attention typically examine group differences between younger and older adults, rather than seeing aging as a continuous process. Using correlational analyses, this study examined progressive changes in the magnitude of the attentional blink (AB) associated with aging. Increased age was found to be significantly associated with the ability to detect the second target (T2), whereby older age was correlated with the production of a longer and more pronounced AB; this supports the proposition that aging is associated with reduced inhibitory processes and selective attention. It was also found that AB performance somewhat improves between ages 18-39 years, but tends to decline from 40 years of age onward, providing an interesting and novel finding that AB effects may become more sensitive at this point in time. The AB task may prove useful in the assessment of selective attention in normal healthy adults, as well as changes associated with pathological aging.     

Aging and Spatial Navigation: What Do We Know and Where Do We Go?

Spatial navigation is a complex cognitive skill that is necessary for everyday functioning in the environment. However, navigational skills are not typically measured in most test batteries assessing cognitive aging. The present paper reviews what we know about behavioral differences between older and younger adults in navigational skill and reviews the putative neural mechanisms that may underlie these behavioral differences. Empirical studies to date clearly identify navigation as an aspect of cognitive function that is vulnerable to the aging process. The few functional and structural neuroimaging studies that speak to neurological correlates of these age-related differences point to the hippocampus, parahippocampal gyrus, posterior cingulate gyrus (retrosplenial cortex), parietal lobes and pre-frontal cortex as structures critically involved in age effects on navigation. Outstanding issues in the field are addressed and productive avenues of future research are suggested. Among these outstanding issues include the necessity of performing longitudinal studies and differentiating between hippocampal and extra-hippocampal contributions to aging in navigation. The field may also be advanced by empirical assessment of navigational strategies and investigations into the multisensory nature of navigation including assessing the relative contributions of visual, vestibular, and proprioceptive function to age differences in navigational skill.     

Examining inhibition of return with multiple sequential cues in younger and older adults

Studies with younger adults have shown that when multiple peripheral cues are presented sequentially, inhibition of return (IOR) occurs at several locations with the greatest IOR at the most recently cued location and the least at the earliest cued location. The inhibitory ability needed to tag multiple locations requires visuospatial working memory, and it is thought that this type of memory may be vulnerable to the effects of aging. The present experiments examined whether older adults would show less IOR at multiple cued locations than younger adults when placeholders were present (Experiment 1) and absent (Experiment 2). Of interest, in both experiments older adults showed an almost identical pattern of IOR, in both magnitude and number of inhibited locations, to that of younger adults. This finding, in conjunction with research on memory-guided saccades, suggests that there may be a form of visuospatial working memory, specific to oculomotor and visual attention processes, that is relatively resistant to the effects of aging.     

Differential effect of aging on synaptic plasticity in the ventral and dorsal striatum

Both the ventral and dorsal striatum are involved in various forms of motor, motivational and learning behaviors. Previously, we demonstrated that several striatum-dependent motor and learning behaviors were reduced in mice with increased age. In this study, we investigated the effects of aging on synaptic plasticity in brain slices containing the nucleus accumbens (NAc) or caudate-putamen (CPu), using electrophysiological recordings. We showed that long-term depression (LTD) was reduced or absent in the NAc of aged C57BL/6 mice, whereas the amount of LTD in the CPu of young and aged mice was similar. The LTD induced by 10-Hz stimulation is NMDAR-dependent in the NAc, but NMDAR-independent in the CPu. Our results suggest that NAc LTD may be more sensitive than CPu LTD to the effects of normal aging with a possibility that NMDAR-dependent LTD may be more susceptible to the aging process than non-NMDAR LTD. We also showed that paired-pulse facilitation was diminished in the NAc and CPu in aged mice, suggesting that aging is accompanied by significant decline in presynaptic function in both the ventral and dorsal striata. The age-related reduction in synaptic plasticity may be a cellular mechanism underlying the age-related impairments in striatum-dependent motor and cognitive functions.     

Spiritual and Religious Implications of Aging with HIV: A Conceptual and Methodological Review

ABSTRACT

Spirituality and religious practices can buffer people from stressful life circumstances and promote positive biopsychosocial outcomes. The beneficial effects of spirituality and religious practices have been documented in aging and HIV. Unfortunately, little is known about spirituality and religious practices in older adults with HIV. As the number of older adults with HIV increases, with an estimated 91,000 adults over 50 being diagnosed with this disease in the United States, spirituality and religious practices may help HIV-positive people to age successfully. Crisis competence and spiritual trajectories are ways of conceptualizing spiritual development when confronting aging with a life-changing event such as a being diagnosed with HIV. Methodological issues in studying spirituality in adults aging with HIV are identified including defining spirituality and religiosity, heterogeneity of the population, timing of diagnosis, mode of transmission, sexual orientation, religious and cultural stigma, and hardiness. Implications for possible interventions are also posited.     

Implications of test revisions for research

Test revisions are increasingly common in psychology and neuropsychology in particular. However, such revisions may alter in complex ways the kind of information obtained, and they may assess traits, abilities, and conditions in ways different from earlier versions. This article outlines some of the problems associated with the revision of tests facing clinicians and researchers. Three broad classes of revision are considered. Part 1 considers the aging of tests, part 2 concerns the aging of participants, and part 3 considers changes in test format. Although the article focuses largely on measures of intelligence and personality, the issues addressed in the article apply to other tests and assessment domains as well.     

Alcoholism,Aging, and Cognition: A Review of Evidence for Shared or Independent Impairments

Little is known about the combined effects of aging and alcoholism on cognitive function, in spite of the potential importance of this knowledge. Studies reported to date have focused on whether aging and alcoholism have shared mechanisms (i.e., the premature aging hypothesis) or independent mechanisms. Most have concluded that the effects of aging and alcoholism on cognition operate through independent mechanisms. However, there are reasons to doubt this conclusion. Many of the studies were not optimally designed to discover shared mechanisms because they used a limited range of ages, included several different groups in their analyses, or had low statistical power. Furthermore, interpretation of the patterns of main effects and interactions between aging and alcoholism is not straightforward. Assumptions must be made about the nature of the impairments in order to interpret the data. This review uses several theories of cognitive aging as an organizing heuristic for interpreting the extant data on aging, cognition, and alcoholism. Some potential shared mechanisms for cognitive deficits in aging and alcoholism are identified, such as information processing speed and proactive interference in working memory. In contrast, some potential independent mechanisms are also identified, such as decay from working and long-term memory. These mechanisms should be used as a base to guide necessary further research.     

积极刻板印象会产生消极影响?

积极刻板印象是对社会群体的积极特质的描述, 以往刻板印象的相关研究主要聚焦于消极刻板印象, 却忽略了对积极刻板印象尤其是其消极影响的探讨。基于此, 分别从种族、性别和年龄这三个方面详细梳理了积极刻板印象的积极影响和消极影响, 并阐述了其产生的条件, 包括积极刻板印象的微妙激活和明显激活、积极刻板印象的准确表述和极端表述、积极刻板印象阐述者的内外群身份、呈现积极刻板印象的文化背景等。未来研究可从集体主义文化、研究领域和对象, 干预方法和消极刻板印象的积极影响等方面进一步探讨。     

Unrecognized Changes in the Self Contribute to Exaggerated Judgments of External Decline

People commonly perceive social conditions as declining. We propose that perceptions of social decline are often a consequence of a bias whereby people mistake change in themselves for change in the world. The present research demonstrates that common personal changes such as the parenthood transition (Studies 1–2) and physical aging (Study 3) may increase a person's sensitivity to dangers and thereby contribute to an illusory perception that external dangers are increasing. We use experimental models of the hypothesized change processes to test whether these common personal changes may contribute to judgments of social decline.