Processing resources and age differences in working memory

This study investigated the performance of young and old subjects on a modified version of the working memory task developed by Baddeley and Hitch (1974). Subjects were required to verify a set of sentences of varying complexity while they repeated aloud zero, two, or four words. The older subjects took longer to verify the sentences, especially when the sentences were grammatically complex, but the effect of concurrent memory load on verification latency was the same in both groups. These results cast doubt on the notion that there is an age-related decline in one general pool of processing resources. They also suggest that older people have greater difficulty with the active processing aspects, rather than with the passive holding aspects, of working memory tasks.     

Similar as well as dissimilar contextual stimuli increase rated similarity

Contextual stimuli from one category increase the rated similarity of stimuli from a second category. In Experiment 1, associates of one of the members of pairs of target words increased the rated similarity of the members slightly more than did much less similar contextual stimuli. In Experiment 2, contextual category names and good exemplars increased the rated similarity of pairs of poor to medium target exemplars and were also rated as more similar to these targets than the targets were to each other. In both cases, the category names resulted in the stronger effect. This ability of contextually similar stimuli to increase rated similarity opposes the distance-density and averaging-judgmental theories of the effect of context on similarity. However, the theory that a positive association exists between the perceived similarity of stimuli and the strength of the category to which they belong explains how both contextually dissimilar and contextually similar stimuli can increase rated similarity.     

Resilient children,psychological wellness,and primary prevention

The concept of heightened resilience or invulnerability in young profoundly stressed children is developed in terms of its implications for a psychology of wellness and for primary prevention in mental health. Relevant literature is reviewed, a skeletal model for studying resilience is outlined, and needed research directions are considered. The latter include expansion of the construct's nomological definitional net, inquiry into the antecedents and determinants of resilience, and the application of such generative information to frame preventive interventions for young, profoundly stressed children.     

A reanalysis of the influence of a "friendly visitor" program

A paper in the American Journal of Community Psychology (AJCP), by Reinke, Holmes, and myself, reported the results of a study of the influence of a friendly visitor program on the cognitive functioning and morale of elderly individuals. The program was reported to have had a significant multivariate effect on a combination of cognitive and morale measures and significant univariate effects on memory, self-perceived health, and activity director's ratings. Being intrigued by the memory finding, I conducted a follow-up study to further investigate the effect of a visitation program on cognitive functioning. In this second study the dependent measures included all of the cognitive variables included in the original study as well as some additional memory variables. The visitation program in the follow-up study had no effect on any of these measures. As a result of my failure to obtain a significant memory effect such as that reported in Reinke et al. (1981), I reanalyzed the data from the original study. In my reanalysis, the only significant effect was a borderline univariate effect for self-perceived health; the multivariate effect did not approach significance. On the basis of my inability to produce the results reported in Reinke et al. when I reanalyzed the original data, I must conclude that the friendly visitor program did not have the effects attributed to it in the original report.     

Force variability in isometric responses

In the present study we examined the contribution of different impulse parameters to peak force variability in an isometric task. Five experiments are reported that each held constant a different impulse parameter while allowing the other impulse parameters to vary. The results indicate that change in force level is the parameter that has the greatest effect on peak force variability, although time to peak force and preload also systematically influence response variability. A formula that accommodates the relation between impulse parameters and force variability is proposed. The data suggest that even in isometric tasks, it is the force-time properties of the impulse, rather than discrete parameters such as peak force, that determine the outcome variability.