Culture, trust, and social networks

Although the role of trust in group processes has been well established, less is known about the role of trust in social network processes. Trust, conceptualized to have generalized and particularistic aspects, was measured by generalized trust (people can be trusted in general) and relationism (people can be trusted if one has relationships), and their relations with social network characteristics of network homogeneity (extent to which one has a number of friends with similar attitudes) and network closure (extent to which one's social network is closed) were examined in three Western (Australia, Germany, and the United Kingdom) and two East Asian countries (Japan and Korea). Although generalized trust was shown to be positively related to network closure across the five countries, generalized trust and relationism had different relations with network homogeneity in different cultures. The results were interpreted in terms of social institutional and cultural differences.     

Attentional bias for body and food in eating disorders: increased distraction, speeded detection, or both?

Previous research suggests that eating disorder patients show an attentional bias for body- and food-related information. However, so far little is known about the mechanisms that underlie the attentional favoring of this particular information in eating disorder patients. In the present study, we used both a body and a food visual search task to study speeded detection and increased distraction in eating disorder patients (n=67) and healthy controls (n=60). Compared with controls, eating disorder patients showed evidence of speeded detection of body-related information, and increased distraction by food information. These results suggest that the mechanism underlying the biased attentional allocation of eating disorder patients varies, and is dependent upon the type of information they are presented with.     

Re-thinking stages of cognitive development: an appraisal of connectionist models of the balance scale task

The present paper re-appraises connectionist attempts to explain how human cognitive development appears to progress through a series of sequential stages. Models of performance on the Piagetian balance scale task are the focus of attention. Limitations of these models are discussed and replications and extensions to the work are provided via the Cascade-Correlation algorithm. An application of multi-group latent class analysis for examining performance of the networks is described and these results reveal fundamental functional characteristics of the networks. Evidence is provided that strongly suggests that the networks are unable to acquire a mastery of torque and, although they do recover certain rules of operation that humans do, they also show a propensity to acquire rules never previously seen.     

Effects of Gender, Education, and Age upon Leaders’ Use of Influence Tactics and Full Range Leadership Behaviors

Relationships of gender, age, and education to leadership styles and leaders’ influence tactics were examined with 56 leaders and 234 followers from a variety of organizations. Leadership behaviors were measured with the Multi-factor Leadership Questionnaire (MLQ—rater version). Influence tactics were measured with Yukl’s Influence Behavior Questionnaire (IBQ). Multivariate Analysis of Variance (MANOVA) was used to test behavioral differences attributed to leaders’ gender, age, and education groups, as well as the interaction of age and education with gender. Results show that gender produced a small direct effect on leadership behaviors. The interaction of gender and education produced consistent differences in leadership behaviors. Implications for future research are provided, and a call for re-analysis of previously published work is advised.     

Role of matrix metalloproteinases in the acquisition and reconsolidation of cocaine-induced conditioned place preference

Persistent drug seeking/taking behavior involves the consolidation of memory. With each drug use, the memory may be reactivated and reconsolidated to maintain the original memory. During reactivation, the memory may become labile and susceptible to disruption; thus, molecules involved in plasticity should influence acquisition and/or reconsolidation. Recently, matrix metalloproteinases (MMPs) have been shown to influence neuronal plasticity, presumably by their regulation of extracellular matrix (ECM) molecules involved in synaptic reorganization during learning. We hypothesized that inhibition of MMP activity would impair the acquisition and/or reconsolidation of cocaine-conditioned place preference (CPP) in rats. Intracerebral ventricular (i.c.v.) microinjection of a broad spectrum MMP inhibitor, FN-439, prior to cocaine training suppressed acquisition of CPP and attenuated cocaine-primed reinstatement in extinguished animals. In a separate experiment, the cocaine memory was reactivated on two consecutive days with a cocaine priming injection. On these two days, artificial cerebral spinal fluid (aCSF) or FN-439 was administered either 30 min prior to or 1 min after cocaine-primed reinstatement sessions. Infusion of FN-439 partially impaired retrieval of the cocaine-associated context when given 30 min prior to cocaine. In both groups, however, FN-439 suppressed reinstatement compared with controls on the third consecutive test for cocaine-primed reinstatement, when no FN-439 was given. Control experiments demonstrated that two injections of FN-439 + cocaine given in the home cage, or of FN-439 + saline priming injections in the CPP chambers did not disrupt subsequent cocaine-primed reinstatement. These results show for the first time that (1) MMPs play a critical role in acquisition and reconsolidation of cocaine-induced CPP, and (2) rats demonstrate apparent disruption of reconsolidation by an MMP inhibitor after extinction and while they are under the influence of cocaine during reinstatement.     

The efficacy of cue exposure with response prevention in extinguishing drug and alcohol cue reactivity

It has been suggested that drug cue‐elicited urges and psychophysiological reactions are the results of Pavlovian conditioning processes and that it should be possible to extinguish these responses with cue exposure with response prevention. It has already been shown that subjective cue‐elicited urges can be extinguished, but it is unclear whether this is also true for cue‐elicited psychophysiological arousal. This was tested in the present study in a heterogeneous sample of drug and alcohol dependent patients. It was found that cue‐elicited urges can indeed be extinguished. However, such a clear pattern of extinguished cue reactivity was not found for the psychophysiological measures. Furthermore, the extinction of drug urges was not specific for cue exposure treatment. It is concluded that cue‐elicited psychophysiological arousal does not underlie subjective cue reactivity and may not reflect Pavlovian conditioned drug responding. Copyright © 2006 John Wiley & Sons, Ltd.     

Distribution of the product confidence limits for the indirect effect: Program PRODCLIN

This article describes a program, PRODCLIN (distribution of the PRODuct Confidence Limits for INdirect effects), written for SAS, SPSS, and R, that computes confidence limits for the product of two normal random variables. The program is important because it can be used to obtain more accurate confidence limits for the indirect effect, as demonstrated in several recent articles (MacKinnon, Lockwood, & Williams, 2004; Pituch, Whittaker, & Stapleton, 2005). Tests of the significance of and confidence limits for indirect effects based on the distribution of the product method have more accurate Type I error rates and more power than other, more commonly used tests. Values for the two paths involved in the indirect effect and their standard errors are entered in the PRODCLIN program, and distribution of the product confidence limits are computed. Several examples are used to illustrate the PRODCLIN program. The PRODCLIN programs in rich text format may be downloaded from www.psychonomic.org/archive.