Biomedical subjects

R L Babcock

Publications and source records attributed to R L Babcock.

6 recordsLinked to original sources

PubMed1997

A comparison of the factor structure of processing speed for younger and older adults: testing the assumption of measurement equivalence across age groups.

The purpose of this study was to investigate measurement equivalence of processing speed measures for different age groups. A structural equation modeling approach was used to investigate a measurement model and the factorial invariance between younger and older adults on speed measures. The analyses concurrently examined whether speed-related abilities dedifferentiate with increasing age. One hundred and forty-four younger and 105 older adults completed 9 measures designed to assess motor speed, alphanumeric speed, and geometric speed. Results indicated that although the number of factors and the factor loadings were invariant across age groups, the interfactor correlations, the variance-covariance matrices, and the unique variances differed across groups. Furthermore, a second-order speed factor seemed to explain much of the variance in the 3 first-order factors, although this higher order factor accounted for slightly more variance among the older group than among the younger group. The results suggest that there is sufficient evidence of measurement equivalence on the current speed measures across the 2 adult age groups and, in addition, provide evidence of dedifferentiation.

Adolescent↗

PubMed1994

Analysis of adult age differences on the Raven's Advanced Progressive Matrices Test.

The purpose of this project was to examine the nature of performance, and specifically, age-related performance, on the Raven's Advanced Progressive Matrices (APM) Test (Raven, Court, & Raven, 1983). In the 1st of 2 studies, 2 tests presumed to measure each of 4 hypothesized components of the APM and 3 tests presumed to measure processing speed were presented to 165 young adults. On the basis of correlational and confirmatory analyses, 1 of the components was not included in Study 2. The 2nd study was designed to examine the influence of the 3 remaining components, processing speed, and working memory on the individual and age-related differences on the APM. Participants included 183 adults between the ages of 21 and 83. The results suggest that although all 3 components are important to performance on the APM, rule application tasks seem to hold the most promise in accounting for age-related variance on the APM.

Adult↗

PubMed1991

Effects of adult age on structural and operational capacities in working memory.

Eight experiments were conducted in which young adults and older adults were asked to report the latest value of 1 of several continuously changing numeric or spatial variables. Accuracy of reporting the current value of the target variable was lower with increases in the number of potentially relevant variables and with increases in the number of required processing operations. Young and older adults exhibited similar effects of the number of potentially relevant variables (hypothesized to be sensitive to the structural capacity of working memory) and of the number of required processing operations (hypothesized to be sensitive to the operational capacity of working memory), but older adults were generally less accurate than young adults.

Adult↗

PubMed1990

Effects of increased processing demands on age differences in working memory.

Three studies investigated (a) the plausibility of the claim that increasing the processing demands in a memory task contributes to greater involvement of a central processor and (b) the effects of altering reliance on the central processor on the magnitude of age-related differences in working-memory tasks. In the first study, young adults performed versions of 2 tasks presumed to vary in the degree of reliance on the central processor. In the second and third studies, young and older adults performed versions of a computation-span task that were assumed to vary along a rough continuum of the amount of required processing. The results indicated that although a central processor appears to be involved when working-memory tasks require simultaneous storage and processing of information, age-related differences in working memory seem to be determined at least as much by differences in the capacity of storage as by differences in the efficiency of processing.

Adult↗

PubMed1989

Effects of adult age and working memory on reasoning and spatial abilities.

Three predictions were derived from the hypothesis that adult age differences in certain measures of cognitive functioning are attributable to age-related reductions in a processing resource such as working-memory capacity. Each prediction received at least some degree of empirical support in a study involving 120 males ranging between 20 and 79 years of age. First, older adults exhibited greater impairments of performance than did young adults when task complexity increased and more demands were placed on the limited processing resources; second, the magnitudes of these complexity effects were highly correlated across verbal (reasoning) and spatial (paper folding) tasks. Finally, statistical control of an index of a working-memory processing resource attenuated the effects of age on the measures of cognitive performance. It was concluded that further progress in understanding the mechanisms of the relation between age and cognitive functioning will require improved conceptualizations of the nature of working memory or other hypothesized mediating constructs.

Adult↗

PubMedDate not supplied

Computer testing of memory across the adult life span.

This study was designed to investigate whether differential experience with and reactions to computers among adults of different ages impact on adult age differences in computer memory testing. Participants were 141 community-dwelling adults, aged 18 to 87. Computer experience, computer anxiety, computer attitudes, and computer self-efficacy were measured in addition to several demographic items. Participants also completed a working-memory test on a desk top computer. Age was positively correlated with computer anxiety, but was not correlated with computer attitudes. In addition, older adults had less computer experience and lower computer self-efficacy. Computer experience, anxiety, and self-efficacy significantly mediated the relationship between age and computer-tested working memory performance. The results lend support to a model of cognitive aging that emphasizes the role of ability-extraneous factors in accounting for some of the observed age-related differences in computer-tested memory.

Adolescent↗