Food anticipation and lever-directed activities in rats

Three experiments are described which elaborate some of the conditions under which rats will contact and manipulate a periodically presented retractable lever. Experiment 1 demonstrated that (i) initial manipulative oral and manual contact with the lever was facilitated if the rat had previous experience of food delivery in the experimental chamber; (ii) persistence in contacting the lever on successive presentations was a function of whether food continued to be presented in the experimental environment; and (iii) food satiation significantly reduced the tendency of the rat to contact the lever even though an expectancy of food had previously been established under conditions of food deprivation. Experiment 2 suggested that the tendency to approach and contact the lever was in part a function of the local moment-to-moment conditional probability of food delivery. Experiment 3 found that the probability of contacting the lever was higher during presentation of an auditory CS signaling a high rate of food delivery than during stimuli signaling no food at all. These results are interpreted as suggesting that the food-signaling aspects of an appetitive CS and that CS's ability to generate signal-directed behaviors are experimentall separable properties.     

Are curmudgeon personality scales resistant to response distortion?

Curmudgeon personality, which is assessed by having participants evaluate a heterogeneous set of attitude objects, provides an applied value beyond that of more established personality traits. Recent research, for instance, suggests that curmudgeon personality is distinct from the Five Factor Model personality traits and that it predicts unique variance in important criteria, such as job attitudes and well-being. In the current paper we contribute to this literature by testing an explanation of how curmudgeon personality is distinct from other traits—their potential resistance to response distortion. We estimated response distortion for scales of curmudgeon personality and FFM traits across two quasi-experimental studies. As expected, the score shifts between nonapplicant and applicant conditions were smaller for scales of curmudgeon personality compared to scales of emotional stability and conscientiousness. We argue that curmudgeon personality scales may be more resistant to response distortion than are measures of other traits because curmudgeon personality items are semi-implicit and lack an obvious desirable response. The resistance to response distortion should serve as a call to future researchers to test the criterion validity of curmudgeon personality in regard to performance criteria.     

EVENT-RELATED BRAIN POTENTIALS, EYE MOVEMENTS, AND READING

Abstract— This article compares studies that use event-related brain potential (ERP) and eye movement data to examine changes in reading behavior when a text is read twice. Although the types of information provided by these methodologies are different, both indicate that rereading a text facilitates many aspects of processing. ERPs provide a method for measuring comprehension and memory processes separately, while eye movements provide a continuous record of performance and allow changes in reading behavior to be localized to specific words. The results from these studies are compatible. However, converging evidence is not always found when different paradigms are contrasted, and diverging results can provide important information. To facilitate comparison across experiments, we suggest using a common set of materials for both paradigms. We conclude that comparing the results of research based on more than one paradigm provides a more complete understanding of the processes involved in reading.     

Musical notation for the keyboard: An examination of stimulus-response compatibility

A recent stimulus-response compatibility model was used to provide a performance evaluation of an experimental notation for the keyboard in which pitch varies horizontally in visual space. One hundred and twenty subjects performed a choice reaction time task using either the horizontal notation or a more traditional vertical notation. Half the subjects in each notation group received white noise and half received pitch-varying feedback with responses. A horizontal display advantage was revealed when rules of the model were applied to data analyses. Further, the horizontal display advantage was not dependent on the nature of the feedback. In a second experiment, performance of musicians and non-musicians was compared using the horizontal and vertical notations. Musicians' performance was uniformly better than that of non-musicians, and did not differ with notation orientation. The findings support the use of non-traditional horizontal notations for novice performance on a keyboard instrument.     

Order effects in belief updating with consistent and inconsistent evidence

The current study tests for the presence of differential order effects in evaluation tasks with consistent and inconsistent evidence as predicted by the Hogarth and Einhorn (1992) belief-adjustment model. The results, based on both between-subjects and within-subjects experiments, demonstrate that there were significant recency effects with inconsistent evidence as predicted, larger recency effects when the inconsistent evidence was farther apart in subjective value as predicted, and significant recency effects even when subjects were given training designed to both help them understand the task as completely as possible and to be better able to assess the pieces of evidence. By including a within-subjects design, we were able to demonstrate that the difference in subjective value between two pieces of evidence is the primary factor influencing the magnitude of the recency effect, regardless of whether the evidence is consistent or inconsistent. This latter finding is unique and contrary to previous research and theory.     

Family preservation using multisystemic treatment: Long-term follow-up to a clinical trial with serious juvenile offenders

In a randomized clinical trial, multisystemic family preservation was shown to significantly reduce rates of criminal activity and incarceration in a sample of 84 serious juvenile offenders and their multi-need families. In the current study, archival records were searched for re-arrest an average of 2.4 years post-referral. Survival analysis showed that youths who received multisystemic family preservation were less likely to be re-arrested than were youths who had received usual services. Such results represent the first controlled demonstration that family preservation, when delivered via a clearly specified treatment model, has lasting effects with serious juvenile offenders. Implications for family preservation and juvenile justice research are discussed.     

Chronic Stress as a Mediator of Acute Stress: The Case of Hurricane Hugo1

This study explored one mechanism through which acute disaster stress (injury, life threat, property damage, loss) may produce lasting psychological distress (depression, anxiety, somatization, hostility). More specifically, the study examined the mediating roles of seven domains of chronic stress (marital, parental, filial, financial, occupational, ecological, physical) within a sample of 930 disaster victims and controls. The results provided strong support for the hypothesis that chronic stress mediates the long-term effects of acute disaster stress on psychological distress. The main effects of loss, though limited in strength, were completely explained by victims’ higher financial, marital, filial, and physical stress. The effects of injury, though quite strong, were largely mediated by these same domains of chronic stress. Likewise, the effects of life threat were largely mediated by all these domains plus ecological stress. A mediational model was not appropriate for understanding the consequences of property damage because it did not exhibit a main effect on psychological distress.