与年龄相关的认知速度减慢及学习改善过程

该工作应用人机对话方式完成心算、符号数字、数字鉴别和计数四项作业认知速度年老减慢及学习改善过程的研究,被试３５０人,４６—７５岁。研究结果表明：四项认知作业速度随年老进行性减慢;然而,老年人经学习训练认知作业速度可明显改善。上述变化程度与作业所需时间有密切关系,提示年老过程中枢信息加工过程速度的减慢快于外周感觉─运动过程速度的减慢,学习改善作用也可能主要是中枢过程速度的提高。     

认知作业年老化的比较研究

用言语—操作和人机对话两种方式完成１２项认知作业年老化比较研究,被试２４２人,４６－７５岁。结果表明：（１）一些作业（符号数字、视觉数字广度、听觉数字广度、词对联想学习、图象自由回忆和无意图形再认）成绩随年老明显下降,另一些作业（图象分类、卡片分类、心算和矩阵填图）成绩不随年老明显降低;（２）再次验证心算、符号数字、数字鉴别和计数四项非词语性作业速度随年老进行性减慢。     

不同认知作业年老化特点的比较研究

本工作应用自行设计的软件程序和微机人机对话方式,完成六项认知作业的年老化特点的比较研究,被试506人,46—75岁。研究结果表明:1)“心算”和“符号数字”两项作业完成速度随年老迅速减慢,但测验成绩随年老缓慢降低,速度变化是该两项作业年老化过程的主要特点;2)“数字鉴别”和“计数”两项作业完成速度随年老减慢较缓;3)“双位数字顺序回忆”和“无意义图形再认”两项作业测验成绩随年老下降迅速,但前者更为明显;4)速度和成绩两项指标的个体差异均随年老有增大趋向。     

年老过程认知作业完成量与作业速度相互关系的研究

本工作应用自行设计的计算机逐级限速程序,研究了年老过程四项认知作业完成量与作业速度的相互关系。被试350人,46—75岁。研究结果表明:1、随着计算机所限时间的缩短,各项作业完成量均随年老下降迅速,作业完成量对于作业速度的依存关系随年老表现极为明显;2、在逐级限速条件下,四项认知作业完成量的年老敏感性顺序与作业速度的年老敏感性顺序基本相同,即是:符号数字、心算、计数和数字鉴别。     

额区脑波年老化特点及其与某些认知能力的相关性

对１２０名中老年被试（４６－８０岁）,完成双额脑波年老化特点０及其与某些认知能力相关性的研究。认知能力测验共１２项作业,包括４项作业速度和１０项作业成绩共１４项指标。结果表明：（１）双额脑波α峰频率随年老低移,α功率随年老有增加趋势;（２）年老过程３项作业速度与双额α峰频率相关性显著,但仅“图象自由回忆”成绩与双额α峰频率及右额α功率相关性显著。     

非词语性认知作业速度年老衰减规律的数学描述

应用两维年龄多作业回归分析方法,研究了四项非词语性认知作业速度年老衰减规律的数学描述形式。被试共７３４名,４６─７５岁。结果表明：五个年老组与４６─５０岁组作业时间之间呈线性函数关系,其线性方程的斜率值随年老组的增龄而增大。     

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     

成人非字词作业速度的随龄减慢及其与汉字作业的比较

以３００名２０￣７９岁成人为被试,并以１０岁段划分为６个年龄组,完成了非字词作业速度的随龄减慢及其与汉字作业的比较研究。结果表明：（１）数字鉴别、数字旋转、心算、符号数字和图形空间定位五项非字词作业均随增龄而显著减慢;（２）元分析结果表明３０－３９岁组到７０－７９岁组５个年龄组上述非字词作业反应时均为２０－２９岁组的平方函数,而且,非字词作业速度减慢的程度在６０岁后明显增大;（３）符号数字和数字鉴     

速度与认知成绩及年龄关系的研究

应用累加成绩－反应时曲线比较研究了青年组与老年组五项作业速度与成绩之间的关系,这五项作业是数字旋转,心算、符号数字、汉字数字和图形空间定位,结果表明：（１）老年组五项作业的累加成绩－－反应时曲线均较青年组上升缓慢,表明老年组需要较长的反应时,便可获得与青年人相当的累加是分;（２）老年组累加成绩－反应时曲线上升的快慢还与作业的性质及难度有一定。上述结果表明,在所研究作业的难度范围内,速度减慢是老年人     

教育因素对认知功能年老化过程的影响

应用言语－操作和人机对话两种方式共１２项作业,完成年龄和教育因素对认知功能影响的研究,被试共７３４人,４６－７５岁．结果表明：（１）年龄和教育因素对认知成绩的影响因作业而异,分别为年龄影响明显（图象自由回忆和无意义图形再认）、教育因素影响明显（卡片分类、图象分类和矩阵填图）、年龄和教育因素影响均明显（符号数字、词对联想学习、听觉和视觉数字广度）或均不明显（心算）．（２）四项非词语性作业速度明显受年龄和教育因素的双重影响．     

Cognitive Performance and the Role of Control Beliefs in Midlife

Midlife has been touted as being a time of peak performance in many different areas of functioning. In the present study, we investigated whether this was true for cognitive functioning on tasks assessing speed, reasoning, short-term memory, and vocabulary. We also explored the extent to which levels of cognitive functioning could be attributed to individual differences in general control beliefs. Middle-aged adults showed little or no cognitive declines on speed, reasoning, and short-term memory measures relative to the young and outperformed the young on vocabulary. Relative to the elderly, middle-aged adults scored higher on all tasks except vocabulary, for which there were no differences. Adults in midlife, on the other hand, had lower scores on measures of general control beliefs compared to younger adults. Thus, although midlife is a time of high cognitive functioning, it is also a time of lower beliefs about control. To investigate the relationship between control beliefs and cognitive performance, we used structural equation modeling. The models showed that for adults in midlife, control beliefs were predictive of performance but only for the reasoning task after background variables were considered. Specifically, high levels of control beliefs were associated with better cognitive performance. More work is needed to identify mediational processes linking control beliefs and cognitive performance for various age groups and to determine whether some cognitive processes are more controllable than others.     

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.     

Protective effect of practice on cognition during aging: implications for predictive characteristics of performance and efficacy of practice

In the present study, the effect of previous experience on spatial memory, which required the retention of information either over long intervals or within a single session, was longitudinally tested in the water maze in male F-344 rats that were from 6 to 24 months of age. Performance in these tasks was found to be age-dependent (Markowska, 1999). Other behavioral tasks in the straight alley and with a visible platform in the water maze controlled the noncognitive components of performance. For all tasks, performance was significantly correlated between 12-month-old and 18-month-old rats, indicating that cognitive performance at the early, but not advanced, stage of aging could be predicted from performance at a younger age if the novelty of the first exposure to the task was eliminated. The protective effect of experience was more robust in the reference memory task as compared to the working memory task and was modified by age when training was initiated. Behavior during the probe trials was more sensitive to the effect of aging and more resistant to the beneficial effect of practice as compared to the performance in the platform trials. The speed of swimming of experienced rats progressively decreased with age only when tested in the cognitive tasks but not in the straight alley. This indicates that speed of swimming during cognitive tasks does not exclusively reflect the ability to swim, but might be also affected by the cognitive demands of the task. Protective effect of experience on cognition was not modified by restriction in diet.     

Aging and time-sharing aspects of executive control

A particularly important aspect of executive functioning involves the ability to coordinate two simultaneous activities. The role of this aspect of executive functioning in adult-age differences in cognitive performance was examined in a study involving 150 adults between 20 and 91 years of age who performed the same visual-motor tracking task with three different primary tasks. The participants also performed several additional cognitive tasks that allowed examination of the relation of time-sharing efficiency to other types of cognitive functioning The results were consistent with the existence of a distinct time-sharing ability because the time-sharing costs in the three dual-task combinations were significantly correlated with one another but only weakly correlated with other cognitive variables. Increased age was associated with reductions in time-sharing ability, and greater efficiency in performing two tasks at once was associated with better performance on tasks assessing spatial, reasoning, and memory abilities. Although this pattern is what one would expect if executive processes contribute to age differences in cognitive functioning, the effects were smaller than those associated with a perceptual speed construct.     

Inhibitory processes, working memory, phonological awareness, naming speed, and early arithmetic achievement

This study identified the cognitive processes that underlie the individual differences in early mathematical performance in elementary school children. Taking into account the Baddeley framework multicomponent model, the inhibitory processes, working memory, phonological awareness, and naming speed are considered to be related to early math learning. To examine this relationship, we compared the performance of a total of 424 typically developing middle-class children, aged between 4 and 7 years in a battery of cognitive and early numeric tests: The Utrecht Early Numeracy Test, the Rapid Automatized Naming Test, Spanish version of the Stroop task, the Numeracy Interference Test, Digit Span test, and Phonological Knowledge Test. The mean age of the participants was 72.21 months (sd = 14.8), and 48.6% were male and 51.4% were female. The results demonstrated that children performing worst on central executive, phonological processing, and inhibitory processes showed lower results in early mathematical tasks measured by The Utrecht Early Numeracy Test. Results supported the notion that the executive system is an important predictor of children's mathematical performance.     

Structural constraints on process explanations in cognitive aging

Much of the current research in the area of cognitive aging has been focused on investigating specific processes presumed to be responsible for the age differences observed in particular cognitive tasks. A central thesis of this article is that age-related effects on cognitive variables seldom occur in isolation, and hence, they are best interpreted in the context of the structural interrelations that exist among variables and the relations of age on that organizational structure. Results from analyses of 2 separate data sets suggest that large proportions of the age-related effects across a wide range of cognitive variables are shared and that independent, or unique, age-related effects often contribute relatively little to the age differences observed in many cognitive variables. These findings imply that it is important to consider the structure within which a variable occurs when attempting to investigate the processes responsible for age-related differences on that variable.     

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 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.     

Examining methodological variation in response inhibition: The effects of outcome measures and task characteristics on age-related differences

This study addressed methodological issues common to developmental studies on response inhibition. Age-related differences were investigated using two Stroop-like tasks with different levels of complexity and comparing different outcome measures in a sample of 340 children and adolescents aged 7–15 years. First, speed and accuracy of task performance were examined; the results showing that improvement in speed continued until age 13 in both the basic naming task and the two inhibition tasks. Improvement in accuracy was less consistent and continued until age 9 or 13 years. Second, two different algorithms were employed to control for the effects of basic processes in inhibition tasks. The difference algorithm indicated age-related differences similar to those for speed. The ratio algorithm, however, suggested earlier deceleration of development of response inhibition at 9 or 11 years of age. Factors related to the cognitive requirements and presented stimuli also had an effect on the results. The present findings shed light on the inconsistencies in the developmental studies of response inhibition and demonstrated that the selection of outcome measures and task characteristics are critical because they affect the way development is depicted.     

Previous reward decreases errors of commission on later ‘No‐Go’ trials in children 4 to 12 years of age: evidence for a context monitoring account

Inhibitory control is widely hypothesized to be the cornerstone of executive function in childhood and the central deficit in a number of developmental disorders, including attention‐deficit/hyperactivity disorder (ADHD). However, recent evidence from adults indicates that performance on response inhibition tasks may primarily reflect non‐inhibitory attentional control (context monitoring) processes. Yet it may be that inhibition plays a more central role in childhood – a time when the architecture of cognitive processes might be more transparent due to wide variability in skill level. Here we directly test inhibitory and context monitoring explanations of task performance on a Go/No‐Go task in a large group of children 4–12 years of age. We conclude that traditional inhibitory conceptualizations of task performance on the Go/No‐Go task cannot account for our findings, calling into question evidence supporting a central role for inhibitory control in cognitive development or developmental psychopathology.