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Biomedical subjects

S J Czaja

Publications and source records attributed to S J Czaja.

13 recordsLinked to original sources

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.

Adult↗

Aging, motor control, and the performance of computer mouse tasks.

Because of the increased presence of computers in work and everyday life and the demographic "graying" of America, there is a need for interface designs that promote accessibility for older people. This study examined age differences in the performance of basic computer mouse control techniques. An additional goal of the study was to examine the influence of age-related changes in psychomotor abilities on mouse control. A total of 60 participants in 3 age groups (20-39 years, 40-59 years, and 60-75 years) performed 4 target acquisition tasks (pointing, clicking, double-clicking, and dragging) using a computer mouse. The data indicated that the older participants had more difficulty performing mouse tasks than the younger participants. Differences in performance attributable to age were found for the more complex tasks (clicking and double-clicking). Furthermore, age-related changes in psychomotor abilities were related to age differences in performance. We discuss applications to computer interface designs. Actual or potential applications of this research include specifications for computer mouse design to accommodate older populations.

Adult↗

Furniture tipping accidents: redesign for prevention.

A large public service organization was concerned with protection of its customers against hazards associated with furniture tipping in public use concourses. Because no injury experience was available for analysis, hazard patterns for tipping accidents were developed from an observational study of public interaction with the furniture. For each hazard pattern, anthropometric models were used to find the probability of the furniture being safe from tipping, for different age and gender combinations. A safety criterion was developed from this modeling, and used to change the weights of some furniture items to resist tipping. These modifications have now been implemented and are in widespread use. Implications for broader application of these models to the development of valid tipping standards for furniture are discussed.

Accidental Falls↗

Age differences in attitudes toward computers.

It is commonly believed that older adults hold more negative attitudes toward computer technology than younger people. This study examined age differences in attitudes toward computers as a function of experience with computers and computer task characteristics. A sample of 384 community-dwelling adults ranging in age from 20 to 75 years performed one of three real-world computer tasks (data entry, database inquiry, accounts balancing) for a 3-day period. A multidimensional computer attitude scale was used to assess attitudes toward computers pretask and posttask. Although there were no age differences in overall attitudes, there were age effects for the dimensions of comfort, efficacy, dehumanization, and control. In general, older people perceived less comfort, efficacy, and control over computers than did the other participants. The results also indicated that experience with computers resulted in more positive attitudes for all participants across most attitude dimensions. These effects were moderated by task and gender. Overall, the findings indicated that computer attitudes are modifiable for people of all age groups. However, the nature of computer experience has an impact on attitude change.

Adult↗

An assessment of falls in elderly men and women.

BACKGROUND: The assessment of falls in the elderly has moved from disease-oriented approaches, which attempt to identify single causative factors, to performance-oriented evaluations of functional deficits. This study examined the abilities of elderly fallers and nonfallers to perform various functional activities and to provide some rationale for performance differences by assessing the integrity of specific systems within the sensory, central processing control, and effector components of balance control. METHODS: Twenty-two elderly subjects, aged 69-93 years, categorized as either a faller or a nonfaller, were assessed on their ability to perform the functional activities of static balance, walking, and stair descent. In addition, the balance control components of sensory input: vision, vestibular function, and proprioception; the central processing control system components: mental status, selective attention, perceptual style, and simple and choice reaction time; and the effector system: isometric strength were assessed. RESULTS: The data indicated that fallers exhibited significantly reduced static balance, walking and stair descent performance than the nonfallers. The fallers exhibited significantly lower selective attention abilities and increased choice resisted reaction times, both measures of the central processing control system component. The nonfallers exhibited reduced proprioceptive function, suggesting that this is not a major contributor to the performance of balance and mobility skills. CONCLUSIONS: The data suggest that actual performance of mobility skills is an efficient means of identifying potential fallers. The decrements in functional activity performance appear to be related to central information processing control components, specifically selective attention and choice reaction time. The significant correlations between the sensory input, central processing control, and effector components with the functional activities suggest that the marginal declines in the sensory and effector components may have an additive effect, which may adversely affect the ability of fallers to perform the functional activities. The data suggest that selective attention and choice reaction time are the two most significant balance control components predictive of falls.

Accidental Falls↗

Ageing, computer-based task performance, and stress: issues and challenges.

An emerging problem that encompasses both traditional ergonomic as well as macroergonomic concerns involves assessing the potential implications of computer-based tasks for older workers. An increasing older workforce and the influx of computer technology into a wide variety of work settings has motivated both a re-examination of the literature concerning ageing and work performance and research that more directly addresses the computer-interactive task domain. In this paper, we overview this literature and raise a number of crucial issues concerning potential age differences in performance and stress associated with computer-based tasks. Underlying our discussion throughout is the intention of identifying the challenges that await interested practitioners and researchers.

Adult↗

Age differences in the performance of computer-based work.

This study investigated the extent to which age had an impact on the performance of computer-based work. Three simulated real-world computer-interactive tasks that varied in complexity and pacing requirements were evaluated. Ss included 65 women, ranging in age from 25 years to 70 years. The methodology encompassed physiological, subjective, and objective performance measures. The data indicated that previous computer experience and age had a significant impact on the performance of the 3 tasks. Increased age was associated with longer response times and a greater number of errors for all 3 tasks. Age also influenced perceptions of fatigue and task difficulty. The findings are discussed in terms of the implications for training and job design.

Adult↗

A human factors analysis of ADL activities: a capability-demand approach.

Older adults frequently encounter difficulties performing daily living activities. Often times these difficulties arise because environmental demands create barriers which hinder task performance. Currently, there is little empirical data that relate environmental demands to functional capabilities of older adults. The concepts and methods of Human Factors Engineering can be used to accomplish this goal. Human Factors views task performance within a systems context and maintains that successful task performance is dependent on a match between task demands and human capabilities. This article will discuss how Human Factors methodologies can be used to analyze problems encountered by older adults performing routine activities. Data from a study concerned with identifying physiological demands associated with personal and instrumental activities of daily living will be used to demonstrate the utility of using this approach.

Activities of Daily Living↗

Older adults and daily living task profiles.

This paper describes data generated from a comprehensive study in which human factors techniques were applied to the analysis of 25 personal and instrumental activities of daily living (ADLs) performed by 60 older adults (age 55 to 93 years) living in the community. Demand profiles generated from task analysis of video-taped ADLs identify the demands inherent in task activities and the objects and environments associated with them. Examples of four different approaches to examine ADL performance using demand profiles are presented: global descriptions of demands across all ADL tasks, task component profiles, task-specific profiles, and action profiles.

Activities of Daily Living↗

Age differences in life satisfaction as a function of discrepancy between real and ideal self concepts.

Six age groups were compared with respect to discrepancy between real and ideal self concepts and the relationship between life satisfaction and discrepancy in self concepts. The subjects, ranging in age from 20 to 75 years, completed two self descriptive adjective rating scales which assessed real and ideal self concept and a life satisfaction index. Significant differences were found among age groups for real and ideal self concepts, life satisfaction, and discrepancy between real and ideal self concept scores. Age was significantly correlated with real and ideal self concept, discrepancy between real and ideal self concepts and life satisfaction. Life satisfaction was significantly correlated with real self concept and discrepancy between real and ideal self concepts. Trends in the data suggested that the younger subjects (20-25 years) had lower real and ideal self ratings and were less satisfied with their lives than the elderly subjects (60-75 years).

Adult↗

Employment opportunities for older adults: engineering design and research issues.

A challenge facing the engineering community is to find ways to integrate older people into the labor force. Despite laws regarding age discrimination and compulsory retirement, older people's participation in the labor force is declining. Unless strategies are developed to keep older people in the workforce, the issues of economic dependency and intergenerational equity are likely to become formidable in the near future. There are a number of areas where engineering applications can enhance older adults' employment opportunities. These include training, workplace and equipment design, and job design. An overview of current knowledge regarding aging and work is provided. Gaps in the knowledge base are identified as areas for research. Examples of how engineering can contribute to the integration of older people into work settings are presented.

Age Factors↗