Naloxone administration impairs autoshaped learning

Effects of naloxone on acquisition of autoshaped behavior were investigated. Rats deprived to 85% of free-feeding weights were trained to touch a retractable lever; delivery of a food pellet occurred on every trial following lever retraction. The lever was retracted immediately if a touch occurred within 15 s, or automatically after 15 s. Analyses were conducted on number and latencies of touches of the extended lever, nose-pokes (touches) directed at the retracted lever during intertrial intervals (a measure less constrained by ceiling effects than extended lever touches), and unconditioned exploratory rearing activity, measured as touches of a metal strip mounted above the grid floor of the apparatus. In an initial experiment, male Sprague-Dawley rats were given saline or naloxone (2.0 mg/kg, ip) 5 min before a training session of 12 trials. Two days later they were tested, in the absence of drug, in a session of 36 (three blocks of 12) trials. Naloxone depressed training levels of lever responding, in addition to slowing acquisition rate. No effect of naloxone was observed on rearing activity. Previous work showed that injection of saline 5 min before behavioral testing increases the rate of autoshaping compared to injections 30 min before (Messing & Sparber, 1984). Thus, effects of naloxone on acquisition of lever-directed behaviors may have been confounded by behavioral depressant effects and/or by an injection effect such a short time before testing. In a second experiment naloxone (0.5 or 2.0 mg/kg) was injected after five of seven training sessions (12 trials each) to male and female rats. A 6-s delay of reinforcement was inserted between lever retraction and food delivery, slowing acquisition rates and providing the opportunity to test the effects of naloxone throughout a multiple-session task. The low dose retarded acquisition of extended lever touching in both sexes; both doses retarded acquisition of interim lever touching in males. Thus, in some circumstances, post-training naloxone administration may impair learning. The results support the notion that low doses of naloxone may have agonist activity.     

Negotiator cognitions: A descriptive approach to negotiators' understanding of their opponents

Substantial evidence exists that negotiators frequently fail to attain readily available and mutually beneficial outcomes. This paper provides a preliminary model of why these failures occur. We assume that negotiators are decision makers, and that their errors derive from cognitive processes ignored by utility-maximization theories. We focus on one part of the model: the systematic tendency to ignore the cognitions of opponent negotiators. Empirical evidence clarifying negotiators' cognitive processes is generated using verbal protocol techniques in a controlled negotiation task. The results show that subjects simplify the negotiation task, in part by ignoring contingencies introduced by the knowledge possessed by their opponents. The discussion focuses on how subjects simplify the task and how the decision-making perspective helps redirect the negotiation literature.     

The effects of alcohol and delta-9-tetrahydrocannabinol on human physical aggression

Forty male undergraduates were provoked following their ingestion of high or low doses of either alcohol or delta-9-tetrahydrocannabinol (THC). The expression of physical aggression was related to the quantity of alcohol ingested. The high dose of alcohol instigated more intense aggression than the low dose. The high dose of THC, on the other hand, did not increase aggressive behavior. In fact, it tended to produce a weak suppression effect.     

Social integration and social support in a life crisis: Effects of macrosocial change in east Germany

This process evaluation study examined what variables moderate and mediate treatment effects on days in stable housing and client satisfaction for homeless mentally ill clients. In general, demographic characteristics did not moderate either outcome variable. Housing contacts, entitlement contacts, mental health contacts, and supportive services were significant mediators of the treatment effect on days in stable housing. Program contacts, mental health contacts, and supportive services were significant mediators of client satisfaction. The authors thank the National Institute of Mental Health for their financial support (MH43248, MH42357) for this project, Dorothy Gano for word processing and editorial assistance, and Gitry Heydebrand, Melissa Dannelet, Betty Tempelhoff, Ruth Smith, and Laeeq Ahmad for assisting in the interviews of clients. We are also appreciative of the cooperation given to us by the staffs of Malcolm Bliss Mental Health Center, St. Patrick's Center, the Community Advocacy and Support Alliance Program, and the St. Louisemergency shelters. Finally, we thank all of the participants in this study; we hope that their homelessness has now ended. (The conclusions presented in this paper are the sole responsibility of the authors and do not necessarily reflect official National Institute for Mental Health policy.)     

Positive aspects of caregiving as a moderator of treatment outcome over 12 months

The authors examined the influence of positive aspects of caregiving (PAC) as a moderator of treatment outcome across 12 months in 1 of the original sites of the Resources for Enhancing Alzheimer's Caregiver Health I project. They used multilevel random coefficients regression analysis to predict time-varying PAC, depression, behavioral bother, and daily care burden in Alzheimer's caregivers (N = 243; mean age = 60.89, SD = 14.19). They found that time-varying PAC was predicted by time-varying daily care burden. They also found significant effects of time-varying PAC for depression, behavioral bother, and daily care burden. Notably, a PAC x Phase x Treatment effect was found for daily care burden, such that individuals who endorsed less PAC benefited most from the intervention across 12 months. The tendency to positively appraise the caregiving experience (i.e., PAC) in response to chronic stressors such as Alzheimer's caregiving may affect individuals' responsiveness to, and benefit from, interventions, whereas only daily care burden affected the tendency to find enjoyment in caregiving across 12 months. Future intervention research should assess individual PAC in order to better tailor interventions to caregiving needs.     

Neurocognitive predictors of performance‐based functional capacity in bipolar disorder

Neurocognitive impairment can predict functional capacity in individuals with bipolar disorder, though little research has examined whether different neurocognitive domains impact specific types of tasks. This study examined the relationship between several neurocognitive variables and the UCSD Performance‐Based Skills Assessment (UPSA; Patterson et al., 2011) to identify the domains and tests that best predict the performance across the subscales. Forty‐seven euthymic participants who were diagnosed with either Bipolar I or Bipolar II were recruited and assessed on a battery of neuropsychological measures and the UPSA. Correlational and regression analyses were run to identify neurocognitive predictors of UPSA subscales. Per the literature, verbal learning and memory and executive function composites were first examined. Verbal learning and memory predicted the Communication subscale and Total score variables above and beyond the estimated FSIQ and symptom rating scales. In a secondary exploratory analysis, the Benton Judgment of Line Orientation subtest predicted the Finance subscale while the California Verbal Learning Test predicted the UPSA total score. Verbal learning and memory emerged as the strongest predictor of functional capacity, suggesting that this domain should be investigated in future mediational and longitudinal studies with the UPSA.     

Children's Coping in the Context of Disasters and Terrorism

Disasters and terrorism present significant and often overwhelming challenges for children and families worldwide. Individual, family, and social factors influence disaster reactions and the diverse ways in which children cope. This article links conceptualizations of stress and coping to empirical knowledge of children's disaster reactions, identifies limitations in our current understanding, and suggests areas for future study of disaster coping. Coping strategies, developmental trajectories influencing coping, and the interplay between parent and child coping represent critical areas for advancing the field and for informing programs and services that benefit children's preparedness and foster resilience in the face of mass trauma.     

A Comparison of Latent Inhibition and Learned Irrelevance Pre-Exposure Effects in Rabbit and Human Eyeblink Conditioning

The learning of an association between a CS and a US can be retarded by unreinforced presentations of the CS alone (termed latent inhibition or LI) or by un-correlated presentations of the CS and US (termed learned irrelevance or LIRR). In rabbit eyeblink conditioning, there have been some recent failures to replicate LI. LIRR has been hypothesized as producing a stronger retardation effect than LI based on both empirical studies and computational models. In the work presented here, we examined the relative strength of LI and LIRR in eyeblink conditioning in rabbits and humans. In both species, a number of preexposure trials sufficient to produce LIRR failed to produce LI (Experiments 1 & 3). Doubling the number of CS pre-exposures did produce LI in rabbits (Experiment 2), but not in humans (Experiment 4). LI was demonstrated in humans only after manipulations including an increased inter-trial interval or ITI (Experiment 5). Overall, it appears that LIRR is a more easily producible pre-exposure retardation effect than LI for eyeblink conditioning in both rabbits and humans. Several theoretical mechanisms for LI including the conditioned attention theory, stimulus compression, novelty, and the switching theory are discussed as possible explanations for the differences between LIRR and LI. Overall, future work involving testing the neural substrates of pre-exposure effects may benefit from the use of LIRR rather than LI.     

Social–Emotional Factors and Academic Outcomes Among Elementary‐Aged Children

Social–emotional comprehension involves encoding, interpreting, and reasoning about social–emotional information, and self‐regulating. This study examined the mediating pathways through which social–emotional comprehension and social behaviour are related to academic outcomes in two ethnically and socioeconomically heterogeneous samples totaling 340 elementary‐aged children. In both samples, social–emotional comprehension, teacher report of social behaviour, and academic outcomes were measured in a single school year. In both samples, structural equation models showed that the relationship between social–emotional comprehension and reading was mediated by socially skilled behaviour. In one sample, but not the other, the relationship between social–emotional comprehension and math was mediated by socially skilled behaviour. This paper advances our understanding of the mechanisms through which social–emotional factors are associated with academic outcomes. Copyright © 2015 John Wiley & Sons, Ltd.