The role of interference in memory span

In two experiments, we investigated the possibility that susceptibility to proactive interference (PI) affects performance on memory span measures. We tested both younger and older adults (older adults were tested because of the suggestion that they are differentially susceptible to PI). We used two different span measures and manipulated testing procedures to reduce PI for these tasks. For older adults, span estimates increased with each PI-reducing manipulation; for younger adults, scores increased when multiple PI manipulations were combined or when PI-reducing manipulations were used in paradigms in which within-task PI was especially high. The findings suggest that PI critically influences span performance. We consider the possibility that interference-proneness may influence cognitive behaviors previously thought to be governed by capacity.     

Bioethics in a liberal society--political, not moral

This paper argues for the importance of the political context of a society for bioethics. In particular, I argue that in a liberal constitutional society, such as the one we find ourselves in, no particular moral perspective is granted a privileged position. Rather, individuals are allowed to live their lives according to values they adopt for themselves, and the rights granted to protect this ability "trump" social consensus, and place boundaries on the social application of personal moral beliefs and values.     

The Props are Falling Down and We Want to Make Music: A Narrative Perspective on Organisations in Transition (Violins/Violence in Organisations)

While South African society finds itself in the throes of political changes, therapists working within organisations in transition find themselves challenged by the turbulence of transformation. The authors are a group of therapists attempting to understand, from a narrative perspective, the organisational context within which they work. This paper recounts the processes around the design, implementation, and outcomes of a workshop on this theme. The main body of the paper consists of a letter that was sent to participants after the workshop. The reader is invited to join collaboratively in our reflections so as to continue an open-ended, creative process.     

Synchrony effects in cognition: the costs and a benefit

The present study investigated whether younger and older adults’ ability to inhibit distractors in a problem-solving task is affected by synchrony, or the match between circadian arousal periods and time of testing. Consistent with an inhibitory-deficit explanation of synchrony effects, both age groups showed heightened susceptibility to distraction at off-peak relative to peak times. In most instances, increased sensitivity to distraction disrupted problem-solving performance; however, when distracting material was related to task goals, individuals actually benefited from reduced inhibitory efficiency. The present data are also consistent with other research in showing that access to and production of well-learned or familiar responses are not vulnerable to synchrony effects.     

The genesis and use of exemplar vs. prototype knowledge in abstract category learning

Accurate classification of new exemplars in an abstraction paradigm may be due to their similarity to old exemplars rather than to abstract category (or prototype) knowledge. In the present study, subjects received initial training on a two-category problem before being transferred to a task in which half of the exemplar-response pairs had their responses reversed while the remaining half of the pairs were unchanged. When transfer occurred with no delay and involved old exemplars, more errors occurred for changed than for unchanged pairs. This result implies the use of exemplar-specific rather than abstract category knowledge. However, when transfer was delayed by 24 or 72 h, errors occurred equally often for changed and unchanged pairs. This result suggests that exemplar-specific knowledge is no longer used. Since subjects were still able to accurately classify exemplars prior to the transfer task at these delays, some form of abstract category knowledge is implicated.     

Relations of Machiavellian behavior with sales performance of stockbrokers

The hypothesis of a relationship between Machiavellian behavior and sales performance of Christie and Geis was tested with a sample of 110 stockbrokers. Scores on a measure called the Machiavellian Behavior scale were positively and significantly correlated with two self-reported measures of sales performance of the stock-brokers. Present results together with those of two earlier studies supported the hypothesis that salespeople with a Machiavellian orientation are likely to be more sucessful. Analysis of the data also indicated predictive validity and acceptable internal consistency of the Machiavellian Behavior scale. Limitations of the present study and a need for further research are discussed.     

Working memory span and the role of proactive interference.

The authors investigated the possibility that working memory span tasks are influenced by interference and that interference contributes to the correlation between span and other measures. Younger and older adults received the span task either in the standard format or one designed to reduce the impact of interference with no impact on capacity demands. Participants then read and recalled a short prose passage. Reducing the amount of interference in the span task raised span scores, replicating previous results (C. P. May, L. Hasher, & M. J. Kane, 1999). The same interference-reducing manipulations that raised span substantially altered the relation between span and prose recall. These results suggest that span is influenced by interference, that age differences in span may be due to differences in the ability to overcome interference rather than to differences in capacity, and that interference plays an important role in the relation between span and other tasks.     

A computerized test of speed of language comprehension unconfounded by literacy

A computerized version of the Silly Sentences task developed for use with children is found to be equivalent to the pencil‐and‐paper version from the SCOLP test with UK undergraduates, and is usable by a sample of young UK children. Because the sentences are presented aloud instead of being written, the computerized test is not affected by literacy skills. Translated into Kiswahili, the task was used in Tanzanian schools, despite the absence of an electricity supply and a very different cultural background. The decision latencies had a test–retest reliability of 0.69 over 5 months, and were independent of age and baseline decision speed. The task appears appropriate for longitudinal studies, including those in developing countries. Given its simplicity and the correlations with the original SCOLP version of the task, it may also be useful in studies on literate adults. Copyright © 2001 John Wiley & Sons, Ltd.