Relative effectiveness of three stimulus variables for locating a moving sound source

A study is reported in which it is shown that observers can use at least three types of acoustic variables that indicate reliably when a moving sound source is passing: interaural temporal differences, the Doppler effect, and amplitude change. Each of these variables was presented in isolation and each was successful in indicating when a (stimulated) moving sound source passed an observer. These three variables were put into competition (with each indicating that closest passage occurred at a different time) in an effort to determine their relative importance. It was found that amplitude change dominated interaural temporal differences which, in turn, dominated the Doppler effect stimulus variable. The results are discussed in terms of two interpretations. First, it is possible that subjects based their judgements on the potential discriminability of each stimulus variable. However, because the stimuli used involved easily discriminable changes, subjects may instead have based their judgements on the independence of a stimulus variable from different environmental situation conditions. The dominance ordering obtained supports the second interpretation.     

Individual differences and measures of aggression in laboratory studies

After inducing hostility toward a confederate by threatening subjects' self-esteem, subjects were then given the opportunity either to deliver shocks (Experiment 1) or to withhold rewards (Experiment 2) from their confederate. Physiological measures were taken prior to the hostility induction, shortly after the induction and, finally, after the opportunity to aggress. Measures of individual differences relating to aggressive behavior were also considered. While the experimental manipulation was the best predictor in the ‘withholding rewards’ condition, measures of dissipation-rumination tendencies and emotional vulnerability were the best predictors in the ‘shock administration’ condition. In both conditions, systolic blood pressure seemed to reflect differences in arousal as a function of the hostility induction procedure, while subjects in the withhold rewards procedure also showed a decrease in systolic pressure after having an opportunity to aggress toward the confederate. It was concluded that not only is the withholding of rewards a more ethically acceptable procedure than shock administration, but it is also more likely to reflect experimental rather than individual difference affects.     

Dissociation of semantic priming, word and non-word repetition effects by event-related potentials

Two experiments investigated the modulation of event-related potentials (ERPs) by semantic priming and item repetition. In Experiment 1, subjects silently counted occasional non-words against a background of words, a proportion of which were either semantic associates or repetitions of a preceding word. Compared to control items, ERPs to repeated words were distinguished by an early (ca. 200 msec) transient negative-going deflection and a later, topographically widespread and temporally sustained positive-going shift. In contrast, semantically primed words showed a relatively small, topographically and temporally limited positive-going modulation peaking around 500 msec. These data were interpreted as evidence against models of priming and repetition which postulate similar loci for these effects. In Experiment 2, subjects counted occasional words against a background of non-words, some of which were repeated. ERPs to repetitions showed a similar early ERP modulation to that in Experiment 1, and also displayed a later slow positive shift. This latter effect was smaller in magnitude and had a delayed onset in comparison to Experiment 1. It was concluded that the effects of repetition differ as a consequence of whether, prior to their first presentation, items possess a representation in lexical memory.     

Investigation of a social-interactional model of depression with mildly depressed males and females

Recent research has explored social-interactional factors in the etiology and maintenance of depression. The current investigation further explored the social-interactional model using face-to-face interactions between depressed and nondepressed individuals, as well as the applicability of this model to observed differences in male and female depression. Forty depressed and 40 nondepressed subjects interacted with same or opposite-sex partners. The 20-minute interactions were videotaped and scored with a behavioral coding system. Subjects completed questionnaires concerning perceptions of their partners and the interaction. Results indicated that depressed and non-depressed subjects behaved similarly during the interactions. However, depression was associated with a number of socially unskilled behaviors. Depression in males was related to additional skills deficits not observed for females. While male and female self-report of depression did not differ, males consistently reported greater negative affect. Partner impressions differed based upon sex of partner, and not his or her level of depression. The robustness of the social-interactional model and methodological considerations for future research with this model are discussed.This article is based on the first author's master's thesis conducted under the supervision of the second author who is now at Catholic University. Portions of this research were presented at the 32nd annual meeting of the Southeastern Psychological Association.The authors wish to thank George A. Clum and Thomas H. Ollendick for serving as committee members; Teresa K. Meade for her invaluable help in data collection; and Katie Bechtel, Ruth Townsley, and Mike Cobler for their assistance in scoring and coding data. Thanks also to an anonymous reviewer for helpful comments on an earlier draft of this paper.     

The impact of pre-employment integrity testing on employee turnover and inventory shrinkage losses

A major home improvement chain located primarily in the western United States initiated the use of thePersonnel Selection Inventory, a written integrity test, as part of its pre-employment hiring process. For two years only, those job applicants who passed this test and other pre-employment criteria were hired by the chain. Following the introduction of the inventory, there was: (1) a 50% reduction in the number of employee terminations for theft, illegal drug use, and violence over a five year period and (2) a savings in shrinkage losses that amounted to over two million dollars over a two year period.