Impulse and Self-Control From a Dual-Systems Perspective

ABSTRACT— Though human beings embody a unique ability for planned behavior, they also often act impulsively. This insight may be important for the study of self-control situations in which people are torn between their long-term goals to restrain behavior and their immediate impulses that promise hedonic fulfillment. In the present article, we outline a dual-systems perspective of impulse and self-control and suggest a framework for the prediction of self-control outcomes. This framework combines three elements that, considered jointly, may enable a more precise prediction of self-control outcomes than they do when studied in isolation: impulsive precursors of behavior, reflective precursors, and situational or dispositional boundary conditions. The theoretical and practical utility of such an approach is demonstrated by drawing on recent evidence from several domains of self-control such as eating, drinking, and sexual behavior.     

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.     

Psychiatric nurses' experiences with inpatient aggression

Using a survey instrument, the experiences of psychiatric nurses with inpatient aggression were investigated in East London, U.K. On this “Perceptions of Prevalence Of Aggression Scale” (POPAS), annual experiences with 15 types of disruptive and aggressive behavior were rated anonymously. Staff members were also asked to disclose the number of days missed from work due to inpatient violence. On the basis of these POPAS forms, internal consistency of the instrument, mean reported aggression frequencies, and days missed from work due to violence were calculated. Internal consistency of the POPAS appeared to be reasonable. Verbal abuse and threats were experienced by most of the psychiatric nurses during a one‐year period (i.e., by about 80–90 percent of nurses). Sexual harassment or intimidation was also experienced relatively often on an annual basis (68 percent), particularly by female and young staff members. A minority of staff members (i.e., 16 percent) had experienced severe physical violence. Although not prevalent, this type of behavior was most strongly connected with reporting sick. In particular, staff members working with involuntarily admitted patients experienced much (severe) violence during their work. Although the validity of estimates of aggression prevalence with the POPAS instrument needs to be investigated further, such a survey may be helpful in gaining insight rather quickly into the level of day‐to‐day contact with aggressive behavior. Also, since information on verbal, physical, and sexual violence, and on days missed from work, can be provided anonymously, this rather delicate, but essential management information, may be accessed relatively easily with the POPAS. Aggr. Behav. 00:000–000, 2005. © 2005 Wiley‐Liss, Inc.     

Separating the influences of escape and access to preferred activities on problem behavior occurring in instructional contexts

Two individuals with developmental disabilities were observed to engage in destructive behavior when demands were presented, suggesting that the behaviors were maintained by negative reinforcement. Subsequent analyses revealed that (i) the behavior problems persisted when the participants were asked to cease a high‐probability, ongoing activity (walking) while demands were not presented and (ii) problem behaviors ceased when the participants were trained to request access to walking through appropriate means. These findings suggested that the presentation of demands, per se, was not the critical variable in maintaining destructive behavior. Rather, it appeared that restricting the participants from walking, which was only coincidentally necessary in the initiation of demands, set the occasion for the aberrant responses. Subsequent analyses were conducted with one participant to further strengthen this hypothesis. These findings are discussed in terms of the utility of seeking out idiosyncratic and individualized behavioral functions subsequent to initial assessments and their contribution to the growing body of literature regarding the complex interactions of destructive behavior and other naturally occurring high‐rate behaviors. Copyright © 2004 John Wiley & Sons, Ltd.     

Application of Latent Semantic Analysis to Divergent Thinking is Biased by Elaboration

Scoring divergent‐thinking response sets has always been challenging because such responses are not only open‐ended in terms of number of ideas, but each idea may also be expressed by a varying number of concepts and, thus, by a varying number of words (elaboration). While many current studies have attempted to score the semantic distance in divergent‐thinking responses by applying latent semantic analysis (LSA), it is known from other areas of research that LSA‐based approaches are biased according to the number of words in a response. Thus, the current article aimed to identify and demonstrate this elaboration bias in LSA‐based divergent‐thinking scores by means of a simulation. In addition, we show that this elaboration bias can be reduced by removing the stop words (for example, and, or, for and so forth) prior to analysis. Furthermore, the residual bias after stop word removal can be reduced by simulation‐based corrections. Finally, we give an empirical illustration for alternate uses and consequences tasks. Results suggest that when both stop word removal and simulation‐based bias correction are applied, convergent validity should be expected to be highest.