Test modality affects source monitoring and event-related potentials

Two experiments investigated the effect of test modality (visual or auditory) on source memory and event-related potentials (ERPs). Test modality influenced source monitoring such that source memory was better when the source and test modalities were congruent. Test modality had less of an influence when alternative information (i.e., cognitive operations) could be used to inform source judgments in Experiment 2. Test modality also affected ERP activity. Variation in parietal ERPs suggested that this activity reflects activation of sensory information, which can be attenuated when the sensory information is misleading. Changes in frontal ERPs support the hypothesis that frontal systems are used to evaluate source-specifying information present in the memory trace.     

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.     

Natural categorization through multiple feature learning in pigeons

Recently (Troje, Huber, Loidolt, Aust, & Fieder 1999), we found that pigeons discriminated between large sets of photorealistic frontal images of human faces on the basis of sex. This ability was predominantly based on information contained in the visual texture of those images rather than in their configural properties. The pigeons could learn the distinction even when differences of shape and average intensity were completely removed. Here, we proved more specifically the pigeons' flexibility and efficiency to utilize the class-distinguishing information contained in complex natural classes. First, we used principal component as well as discriminant function analysis in order to determine which aspects of the male and female images could support successful categorization. We then conducted various tests involving systematic transformations and reduction of the feature content to examine whether or not the pigeons' categorization behaviour comes under the control of categorylevel feature dimensions-that is, those stimulus aspects that most accurately divide the stimulus classes into the experimenter-defined categories of 'Male' and 'Female'. Enhanced classification ability in the presence of impoverished test faces that varied only along one of the first three principal components provided evidence that the pigeons used these class-distinguishing stimulus aspects as a basis for generalization to new instances.     

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.     

Should subjects be forewarned of the possible psychological consequences of filling out a PTSD questionnaire?

In 1993 Albach investigated the long-term consequences of sexual abuse on psychological health. A group of abused women a a control group of nonabused women were asked to fill in a questionnaire assessing posttraumatic stress disorder (PTSD). For ethical reasons, the abused women were warned that filling in the questionnaire might be emotionally stressful. The control group did not receive this warning. The abused women scored higher on the questionnaire than the nonabused women. The warning they received may have influenced their reports. Our experiment investigated this. 101 psychology students were divided into two groups, one who received a warning and a control group who did not. The hypothesis was that people who had been previously warned would score higher on a PTSD questionaire than people who had not. There were, however, no significant differences in mean PTSD scores and no known initial differences between groups.