基本心理能力老化的认知机制

基本心理能力老化机制是认知老化领域研究热点之一。横断研究与追踪研究表明, 感觉功能、加工速度、工作记忆等信息加工资源的衰退导致了基本心理能力的衰退。但由于相关研究不能进行因果推论, 基本心理能力老化的认知机制尚存在争论。因此本项目拟采用实验室研究和干预实验设计, 通过操纵感觉功能(知觉压力水平)、干预加工速度与工作记忆, 考察基本心理能力的年龄差异的变化, 以期为认知老化理论的深化和拓展提供实验依据。     

Processing speed in normal aging: Effects of white matter hyperintensities and hippocampal volume loss

Changes in cognitive functioning are said to be part of normal aging. Quantitative MRI has made it possible to measure structural brain changes during aging which may underlie these decrements which include slowed information processing and memory loss. Much has been written on white matter hyperintensities (WMH), which are associated with cognitive deficits on tasks requiring processing speed and executive functioning, and hippocampal volume loss, which is associated with memory decline. Here we examine volumetric MRI measures of WMH and hippocampal volume loss together in relation to neuropsychological tests considered to be measures of executive functioning and processing speed in 81 non-demented elderly individuals, aged 75–90. Correlational analysis showed that when controlling for age, both greater WMH volume and smaller hippocampal volume were correlated with slower performances on most tests with the exception of a battery of continuous performance tests in which only WMH was correlated with slower reaction time (RT). We then performed a series of hierarchical multiple regression analyses to examine the independent contributions of greater WMH volume and reduced hippocampal volume to executive functioning and processing speed. The results showed that for the four measures requiring executive functioning and speed of processing, WMH volume and hippocampal volume combined predicted between 21.4% and 37% of the explained variance. These results suggest that WM integrity and hippocampal volume influence cognitive decline independently on tasks involving processing speed and executive function independent of age.     

Aging of theory of mind: The influence of educational level and cognitive processing

Previous studies of theory of mind (ToM) in old age have provided mixed results. We predicted that educational level and cognitive processing are two factors influencing the pattern of the aging of ToM. To test this hypothesis, a younger group who received higher education (mean age 20.46 years), an older group with an education level equal to that of the young group (mean age 76.29 years), and an older group with less education (mean age 73.52 years) were recruited. ToM tasks included the following tests: the second‐order false‐belief task, the faux‐pas task, the eyes test, and tests of fundamental aspects of cognitive function that included two background tests (memory span and processing speed) and three subcomponents of executive function (inhibition, updating, and shifting). We found that the younger group and the older group with equally high education outperformed the older group with less education in false‐belief and faux‐pas tasks. However, there was no significant difference between the two former groups. The three groups of participants performed equivalently in the eyes test as well as in control tasks (false‐belief control question, faux‐pas control question, faux‐pas control story, and Eyes Test control task). The younger group outperformed the other two groups in the cognitive processing tasks. Mediation analyses showed that difficulties in inhibition, memory span, and processing speed mediated the age differences in false‐belief reasoning. Also, the variables of inhibition, updating, memory span, and processing speed mediated age‐related variance in faux‐pas. Discussion focused on the links between ToM aging, educational level, and cognitive processing.     

Effects of sleep deprivation on executive functioning,cognitive abilities,metacognitive confidence,and decision making

Performance on many decision‐making tasks is underpinned by metacognitive monitoring, cognitive abilities, and executive functioning. Fatigue‐inducing conditions, such as sleep loss, compromise these factors, leading to decline in decision performance. Using a 40‐hr sleep deprivation protocol, we examined these factors and the resulting decision performance. Thirteen Australian Army male volunteers (aged 20–30 years) were tested at multiple time points on psychomotor vigilance, inhibitory control, task switching, working memory, short‐term memory, fluid intelligence, and decision accuracy and confidence in a medical diagnosis‐making test. Assessment took place in the morning and night over two consecutive days, during which participants were kept awake. Consistent with previous work, cognitive performance declined after a night without sleep. Extending previous findings, self‐regulation and self‐monitoring suffered significantly greater declines immediately after the sleepless night. These results indicate that the known decline in complex decision‐making performance under fatigue‐inducing conditions might be facilitated by metacognitive rather than cognitive mechanisms.     

Cognitive Mediators of Age-Related Differences in Language Comprehension and Verbal Memory Performance

The present study tried to specify how much processing speed, working memory capacity, and inhibition capability contribute to the effects of aging on language performance. An individual-differences approach was used to examine the component processes that predict performance in language comprehension and verbal long-term memory tasks. A total of 151 participants aged 31-80 completed language processing tasks and a battery of tasks designed to assess processing speed, working memory, and resistance to interference. Latent-construct structural equation modeling was used to examine the relationships of these factors and age to different types of language tasks. The best fit model showed first that all the significant relationships between age and language performance are mediated through reductions in speed, resistance to interference, and working memory; this confirms the validity of the general factor approach of age-related differences in cognitive performance. The best fit model, however, also showed that the contribution of speed and resistance to interference is indirect and mediated by working memory, which appears to play a crucial role in explaining age-related differences in language performance.     

Age-related changes in the efficiency of cognitive processing across the life span

The global-speed and the specific-gain/loss hypotheses have been dominant theoretical frameworks in the recent literature on cognitive development and aging. Few attempts have been made to explicitly assess the predictive power of the two frameworks against each other. We evaluated the extent to which age changes in performance in executive function tasks (involving response selection, response suppression, working memory, and adaptive control) depend on age-related changes in global information-processing speed. Our sample consisted of children, adolescents, adults and seniors. Analysis of covariance and structural equation modeling revealed a mixed pattern of results. Controlling for global speed removed the child vs. adult differences in the speed of responding on the executive function tasks but the senior vs. adult differences remained. This mixed pattern of findings was interpreted to suggest that the effects of advancing age on the speed of responding are mediated by a global mechanism during childhood but during senescence the efficiency of executive functioning seems particularly vulnerable to the effects of age.     

Sex differences in visuospatial working memory: components of cognitive processing

Numerous studies have shown that sex differences in visuospatial tasks vary in size and direction depending on the nature of the task, with large differences favoring males on tasks that require transformations in visuospatial working memory. The cognitive processes underlying these differences were investigated using laboratory tasks developed by Dror and Kosslyn (1994). Four cognitive components of visuospatial working memory were assessed—image generation, maintenance, scanning, and transformation—in an attempt to identify the components that would show differential effects for females and males. The image generation task required retrieval of shape information from long-term memory, generation of a visual image in working memory, and utilization of the information about the shape in a decision task. The image maintenance task required only the latter two processes. The information processing demands required by scanning and rotation tasks came from the need to transform the visual image so that it could be used in decision making. Males responded more quickly on all four tasks (ds between .63 and .77), with no between-sex differences in accuracy. We concluded that speed of processing is central to understanding sex differences in visuospatial working memory. We discuss implications of these findings for performance on real-world visuospatial tasks.     

Cognitive deficits of executive functions and decision‐making in obsessive‐compulsive disorder

The nature of cognitive deficits in obsessive‐compulsive disorder (OCD) is characterized by contradictory findings in terms of specific neuropsychological deficits. Selective impairments have been suggested to involve visuospatial memory, set shifting, decision‐making and response inhibition. The aim of this study was to investigate cognitive deficits in decision‐making and executive functioning in OCD. It was hypothesized that the OCD patients would be less accurate in their responses compared to the healthy controls in rational decision‐making on a version of the Cambridge gambling task (CGT) and on the color‐word interference test and on a version of the Tower of Hanoi test (tower test) of executive functioning. Thirteen participants with OCD were compared to a group of healthy controls (n = 13) matched for age, gender, education and verbal IQ. Results revealed significant differences between the OCD group and the healthy control group on quality of decision‐making on the CGT and for achievement score on the tower test. On these two tasks the OCD group performed worse than the healthy control group. The symptom‐dimension analysis revealed performance differences where safety checking patients were impaired on the tower test compared to contamination patients. Results are discussed in the framework of cognition and emotion processing and findings implicate that OCD models should address, specifically, the interaction between cognition and emotion. Here the emotional disruption hypothesis is forwarded to account for the dysfunctional behaviors in OCD. Further implications regarding methodological and inhibitory factors affecting cognitive information processing are highlighted.     

Age,executive function,and social decision making: a dorsolateral prefrontal theory of cognitive aging

Current neuropsychological models propose that some age-related cognitive changes are due to frontal-lobe deterioration. However, these models have not considered the possible subdivision of the frontal lobes into the dorsolateral and ventromedial regions. This study assessed the age effects on 3 tasks of executive function and working memory, tasks dependent on dorsolateral prefrontal dysfunction; and 3 tasks of emotion and social decision making, tasks dependent on ventromedial prefrontal dysfunction. Age-related differences in performance were found on all tasks dependent on dorsolateral prefrontal dysfunction. In contrast, age-related differences were not found on the majority of the tasks dependent on ventromedial prefrontal dysfunction. The results support a specific dorsolateral prefrontal theory of cognitive changes with age, rather than a global decline in frontal-lobe function.     

The relationship between short‐term memory and working memory: Complex span made simple?

This experiment addresses the question of what makes a working memory measure a good predictor of higher‐level abilities. Verbal and visuospatial processing episodes were interleaved with distinct verbal and visuospatial storage episodes to form four complex span tasks. Although these measures were reliable predictors of reading and mathematics ability in children, they were no more predictive of these abilities than corresponding simple span tasks involving storage alone. However, when individual differences in storage ability and processing capacity were controlled for, residual variance in complex span performance was related to academic ability in some cases. These findings indicate that complex span tasks are multiply determined, and that differences in task structure can dramatically influence the relative importance of these multiple constraints and the predictive power of a complex span measure.     

Cognitive processes in children's reading and attention: The role of working memory,divided attention,and response inhibition

Children experiencing attention difficulties have documented cognitive deficits in working memory (WM), response inhibition and dual tasks. Recent evidence suggests however that these same cognitive processes are also closely associated with reading acquisition. This paper therefore explores whether these variables predicted attention difficulties or reading among 123 children with and without significant attention problems sampled from the school population. Children were screened using current WM and attention task measures. Three factors explained variance in WM and attention tasks. Response inhibition tasks loaded mainly with central executive measures, but a dual processing task loaded with the visual‐spatial WM measures. Phonological loop measures loaded independently of attention measures. After controls for age, IQ and attention‐group membership, phonological loop and ‘central processing’ measures both predicted reading ability. A ‘visual memory/dual‐task’ factor predicted attention group membership after controls for age, IQ and reading ability. Results thus suggest that some of the processes previously assumed to be predictive of attention problems may reflect processes involved in reading acquisition. Visual memory and dual‐task functioning are, however, purer indices of cognitive difficulty in children experiencing attention problems.     

加工速度和工作记忆在认知年老化过程中的作用

研究加工速度和工作记忆在认知能力年老化过程中的作用。被试为20-90岁的健康成人1350名,完成加工速度、工作记忆及一组认知能力测验,应用分层回归分析方法考查在年老化过程中加工速度和工作记忆对多项认知变量的作用量。结果表明,在年老化过程中,加工速度和工作记忆对认知变量的作用量分别约为87% 和76%;二者的综合作用量约为94%。说明加工速度和工作记忆在认知能力年老化过程中起决定作用     

Flexible control in processing affective and non-affective material predicts individual differences in trait resilience

Trait resilience is a stable personality characteristic that involves the self-reported ability to flexibly adapt to emotional events and situations. The present study examined cognitive processes that may explain individual differences in trait resilience. Participants completed self-report measures of trait resilience, cognitive flexibility and working memory capacity tasks, and a novel affective task-switching paradigm that assesses the ability to flexibly switch between processing the affective versus non-affective qualities of affective stimuli (i.e., flexible affective processing). As hypothesised, cognitive flexibility and flexible affective processing were unique predictors of trait resilience. Working memory capacity was not predictive of trait resilience, indicating that trait resilience is tied to specific cognitive processes rather than overall better cognitive functioning. Cognitive flexibility and flexible affective processing were not associated with other trait measures, suggesting that these flexibility processes are unique to trait resilience. This study was among the first to investigate the cognitive abilities underlying trait resilience.     

The involvement of executive functions in prospective memory performance of adults

The present study examines the relationship between prospective memory performance and executive functioning. The four phases of the prospective memory process—intention formation, intention retention, reinstantiation of the intention, and intention execution—are assumed to require different amounts of executive processing, most of which is demanded in the phases of intention formation and intention execution. At present, though, it is still unclear whether, and to what extent, prefrontal executive systems are involved in different kinds of prospective memory tasks, as some findings suggest that prospective memory might rather rely on nonstrategic processes that are unlikely to depend on prefrontal executive systems. Therefore, this study focuses on the following questions: (1) to what degree does executive functioning predict prospective memory performance in different standard prospective memory tasks and, furthermore, are certain executive measures better predictors than others; (2) are age‐related effects in different prospective memory measures due to individual differences in executive functioning; and (3) do age‐related differences in prospective memory exist that are not explained by individual differences in executive functioning. In a sample of 80 adults (20‐80 years), we applied four instruments to measure prospective memory: a traditional single‐task paradigm, two more complex tasks—one time‐based and one event‐based—and a highly complex multi‐task paradigm. We further assessed a broadly defined construct of executive functioning using several standard neuropsychological tests. Results showed that executive functioning did not predict performance in the simple single‐task paradigm. However, executive functioning, but not age, predicted performance in the two more complex standard tests of prospective remembering, and both executive functioning and age predicted performance in the most complex paradigm. In sum, the obtained data underline the assumption that frontal/ executive functions are related to prospective memory performance across a range of prospective paradigms. It also seems clear that age differences in prospective memory performance partially depend on age‐related individual differences in frontal/executive functions.     

Decision-making competence in younger and older adults: which cognitive abilities contribute to the application of decision rules?

Older adults perform worse than younger adults when applying decision rules to choose between options that vary along multiple attributes. Although previous studies have shown that general fluid cognitive abilities contribute to the accurate application of decision rules, relatively little is known about which specific cognitive abilities play the most important role. We examined the independent roles of working memory, verbal fluency, semantic knowledge, and components of executive functioning. We found that age-related decline in applying decision rules was statistically mediated by age-related decline in working memory and verbal fluency. Our results have implications for theories of aging and decision-making.     

Differences in cognitive performance between informal caregivers and non-caregivers

ABSTRACT

Extensive literature exists documenting the relationship between stress and cognition. Caregiving for an individual with Alzheimer’s disease can be aunique and chronic stress experience due to the increasing dependency of the care-recipient as the disease progresses. The current study examines the relationship between stress and cognitive performance in 47 dementia caregivers compared to 47 noncaregiver control participants matched on age, gender, and education. Participants completed measures assessing stress (measured via the Perceived Stress Scale) and seven domains of cognition including episodic memory, working memory, executive functioning, attention, visuospatial processing, processing speed, and implicit memory. Results showed that caregivers had poorer performance than non-caregivers on certain measures of episodic memory, working memory, and executive functioning; while no significant differences were observed on measures of attention, visuospatial processing, processing speed, or implicit memory. In addition, when controlling for general stress, caregiver performance on measures of processing speed and visuospatial processing was also poorer than non-caregivers. By controlling for levels of general stress that may not be related to caregiving, these results show that differences in cognitive performance are unlikely to be explained by general stress alone.     

教育水平对老年人认知能力的影响模式

来自北京三个社区的217位60~85岁的老年人接受了五项基本心理能力测验、感觉功能测查、加工速度和工作记忆容量的测试。运用相关分析、方差分析以及结构方程模型考察了教育水平对老年人基本心理能力的影响。研究得到：（1）从整体上看,教育水平对老年人基本心理能力的积极作用是普遍存在的,不依赖于具体的领域;分水平看,教育水平对认知功能的积极作用随教育水平的高低表现出领域间的差异。（2）教育水平与年龄各自独立地对老年人的认知能力产生影响,教育水平的作用是积极的,年龄的影响是极性的。（3）教育水平对老年人基本心理能力的影响不是直接的,而是以加工速度和工作记忆为中介的。     

抑制和加工速度与液态智力的年老化

研究抑制能力和加工速度在液态智力年老化过程中的相对作用。被试为142名18~85岁健康成年人,完成包括抑制优势反应、加工速度和液态智力共13项测验。分层回归分析显示,抑制能力与年龄相关的特异性变异,在控制简单的速度变量时较控制复杂的速度变量时更大;结构方程分析表明,对液态智力年老化的中介作用,当选取较复杂的速度变量时加工速度的作用更大,而当选取较简单的速度变量时抑制能力的作用更大。研究结果表明,在液态智力的年老化过程中,除了加工速度的作用之外,抑制能力也起重要的中介作用。该结果为认知年老化的抑制理论和执行衰退假说提供了认知行为学研究的证据,并且对加工速度理论作了有益的补充和修正     

Age differences in financial decision making: The benefits of more experience and less negative emotions

The emerging literature on aging and decision making posits that decision‐making competence changes with age, as a result of age differences in various cognitive and noncognitive individual‐differences characteristics. In a national life‐span sample from the United Kingdom (N = 926), we examined age differences in financial decisions, including performance measures of sunk cost and credit card repayment decisions, and self‐report measures of money management and financial decision outcomes. Participants also completed four individual‐differences characteristics that have been proposed as relevant to financial decision making, including two cognitive ones (numeracy and experience‐based knowledge) and two noncognitive ones (negative emotions about financial decisions). First, we examined how age was related to the four financial decision‐making measures and the four individual‐differences characteristics. Older age was correlated to better scores on each of the four financial decision‐making measures, more experience‐based knowledge, less negative emotions about financial decisions, whereas numeracy and motivation were not significantly correlated with age. Second, we found that considering both the two cognitive and the two noncognitive individual‐differences characteristics increased predictions of financial decision making, as compared with considering either alone. Third, we examined how these four individual‐differences characteristics contributed to age differences in financial decision making. Older adults' higher levels of experience‐based knowledge and lower levels of negative emotions seemed to especially benefit their financial decision making. We discuss implications for theories on aging and decision making, as well as for interventions targeting financial decisions.     

语言能力的老化机制：语言特异性与非特异性因素的共同作用

语言能力的衰退是由于一般认知能力衰退引起的, 还是由于语言加工系统的衰退引起的, 抑或是两者的共同作用?研究中测量了青年组和老年组的一般认知能力(加工速度、工作记忆和抑制能力), 以及在词汇、句子和语篇三个水平上的语言理解能力和语言产生能力。结果发现, 一般认知能力、语言理解和语言产生能力都存在年老化现象。分层回归分析表明, 一般认知能力对语言能力的贡献, 以及语言理解能力和产生能力之间的相互贡献在青年组和老年组中是不同的, 且存在词汇、句子和语篇水平上的差异。在词汇水平上, 青年人的成绩能够被一般认知能力和另一种语言能力所显著预测, 而老年人的成绩却不受一般认知因素影响; 在句子水平上, 青年人的成绩仍能被一般认知能力或另一种语言能力所解释, 但这两类变量都无法预测老年人的任务成绩; 在语篇水平上, 青年人理解任务的成绩显著地受到产生能力影响, 而老年人的理解和产生任务成绩则分别可以被一般认知能力和语言理解能力所解释。对组间差异的回归分析表明, 一般认知能力和另一种语言能力对组间差异都有显著贡献, 且前者的贡献大于后者。上述研究结果表明, 语言能力的老化是语言特异性因素和非特异性因素共同作用的结果。