Navigation in the Morris swim task as a baseline for drug discrimination: a demonstration with morphine

A morphine versus saline discrimination was demonstrated using the Morris swim task as the behavioral baseline. The apparatus was a large circular pool filled with water made opaque by floating polypropylene pellets. Rats were placed in the tank in randomly selected locations (12 trials per session) and could escape by swimming to a platform submerged 2 cm below the surface. Morphine (5.6 mg/kg) or saline was injected prior to training sessions. The position of the platform in a given session depended on the drug condition, thus forming the basis for discriminative responding. Three of the 4 rats acquired the discrimination, as evidenced by direct swims to the condition-appropriate platform. Generalization probe sessions were conducted following acquisition. Probe sessions were preceded by injections of morphine (0, 1.0, 3.0, 5.6, or 10.0 mg/kg) and involved placing the rat in the pool for 1 min without a platform. Swim patterns revealed a gradient, with probe swimming more concentrated in the area of the morphine platform position after higher morphine doses. In addition, dose-dependent increases in the likelihood of swimming first to the morphine-associated platform location were obtained. These results illustrate the generality of drug discrimination across different behavioral procedures, and of particular interest with respect to spatial learning, demonstrate interoceptive stimulus control of navigation.     

A Case Study of the Implementation of Outcomes-Based Funding Within a Local United Way System: Some Implications for Practicing Community Psychology

This case study provides an overview of significant organizational change within the United Way system in Franklin County/Columbus, Ohio. Franklin County is a major urban center with a population approaching 1 million. The implementation of outcomes-based funding proved to be a critical factor that served to promote change within the local United Way system. Adoption of outcomes-based funding principles resulted in significant shifts in United Way funding and major policy changes. A chronology of events and stakeholder reactions over a multiyear period are reviewed. The implications of this effort to initiate major, system-level change for the practice of community psychology are discussed.     

Transformational Leadership and Sports Performance: The Mediating Role of Intrinsic Motivation1

We developed and tested a model in which transformational leadership affects sports performance indirectly, through the mediating effects of intrinsic motivation. During the season, 168 university athletes provided data on their perceptions of their coach's transformational leadership and their own intrinsic motivation. At the end of the season, their coaches assessed the performance of the athletes. Using LISREL VIII, three models were estimated following the sequence of mediator tests outlined by Kelloway (1996, 1998). The proposed model received considerable support. The results isolate intrinsic motivation as a mediator of the relationship between transformational leadership and sports performance, suggesting that transformational leadership may enhance intrinsic interest in the task.     

Can competitive paradigms increase the validity of experiments on primate social cognition?

Experiments vary in their ability to distinguish between competing hypotheses. In tests on primate cognition the majority of this variation is due to an experimenter's ability to test primates in valid settings while providing the adequate amount of experimental control. While experimenters studying primate cognition can use methods of control perfected in captivity, it is still very unclear how to design and then objectively evaluate the external validity of new experimental paradigms. I recommend that more effort be allocated to specify how to create relevant test settings for primates. Primate social life is highly competitive. This means that all aspects of primates themselves, including their cognitive abilities, have likely been shaped by the need to out-compete conspecifics. Based on this hypothesis, sophisticated cognitive abilities of primates might best be demonstrated in competitive contexts. Thus, it is suggested that one possible measure of validity is whether investigators integrate a competitive component into their experimental designs. To evaluate this methodological prediction I review the literature on chimpanzee perspective-taking as a case study including several recent studies that include a competitive component in their experimental designs. Accepted after revision: 8 April 2001 Electronic Publication     

Discovery misattribution: when solving is confused with remembering

This study explored the discovery misattribution hypothesis, which posits that the experience of solving an insight problem can be confused with recognition. In Experiment 1, solutions to successfully solved anagrams were more likely to be judged as old on a recognition test than were solutions to unsolved anagrams regardless of whether they had been studied. Experiment 2 demonstrated that anagram solving can increase the proportion of "old" judgments relative to words presented outright. Experiment 3 revealed that under certain conditions, solving anagrams influences the proportion of "old" judgments to unrelated items immediately following the solved item. In Experiment 4, the effect of solving was reduced by the introduction of a delay between solving the anagrams and the recognition judgments. Finally, Experiments 5 and 6 demonstrated that anagram solving leads to an illusion of recollection.     

From Nonhuman to Human Mind: What Changed and Why?

ABSTRACT— Two questions regarding the human mind challenge evolutionary theory: (a) What features of human psychology have changed since humans' lineage split from that of the other apes such as chimpanzees and bonobos? And (b) what was the process by which such derived psychological features evolved (e.g., what were the selection pressures)? I review some of the latest research on chimpanzee and canine psychology that allows inferences to be made regarding these questions.     

“Remembering” emotional words is based on response bias,not recollection

Recent studies have demonstrated that emotional stimuli result in a higher proportion of recognized items that are “remembered” (e.g., Kensinger & Corkin, 2003; Ochsner, 2000), leading to greater estimates of recollection by the dual-process model (Yonelinas, 1994). This result suggests that recognition judgments to emotional stimuli depend on a recollection process. We challenge this conclusion with receiver operating characteristic (ROC) curve data from two experiments. In both experiments, subjects studied neutral and emotional words. During the recognition test, subjects made old-new confidence ratings as well as remember-know judgments. Four models of remember-know judgments were fit to individual subjects’ data: two versions of a one-dimensional signaldetection-based model (Donaldson, 1996; Wixted & Stretch, 2004), the dual-process model (Yonelinas, 1994), and the two-dimensional signal-detection-based model known as STREAK (Rotello, Macmillan, & Reeder, 2004). Consistent with the literature, we found that emotion increases subjective reports of “remembering.” However, our ROC analyses and modeling work reveal that the effect is due to response bias differences rather than sensitivity change or use of a high-threshold recollection process.     

Phonological typicality and sentence processing

In studies of language, it is widely accepted that the form of a word is independent of its meaning and syntactic category. Thus, the relationship between phonological form and grammatical class would not be expected to affect reading time. However, Farmer et al. have now shown that the phonological typicality of a noun or verb influences how rapidly it is read. This finding has implications for both sentence processing and the interpretation of fixation patterns in reading.     

Psychological trauma and PTSD symptoms as predictors of substance dependence treatment outcomes

Psychological trauma and post-traumatic stress disorder (PTSD) may complicate and reduce the effectiveness of treatment for substance use disorders (SUDs). This study assessed trauma history and symptoms of simple and complex PTSD at baseline in a randomized trial of contingency management (CM) compared to standard treatment (ST) with 142 cocaine- or heroin-dependent outpatients. History of exposure to each of eight types of psychological trauma was unrelated to treatment outcome, except for witnessed assaults and emotional abuse. Complex PTSD symptoms were inversely associated with short-term treatment outcomes, and PTSD symptoms were positively related to long-term outcome, independent of the effects of demographics, psychological distress, baseline substance use status, and treatment modality. Complex PTSD symptoms warrant further study as a potential negative prognostic factor in SUD interventions.     

Status generalization in context: The moderating role of groups

Status generalization has been described as a process directly linking social status at the societal level to influence in interpersonal interactions, providing one mechanism through which status inequalities in society are maintained. It is argued in this paper that groups can moderate status generalization when a status characteristic is non-prototypical of the group. Two experiments are reported that measured the relative influence of an older and younger target within different group contexts: an undergraduate student group and a broader university group. In both experiments, the older target was more influential than the younger target in the context of the university group, but the younger target was more influential in the context of the undergraduate student group. Findings are discussed in relation to status generalization and referent informational influence as separate influence processes.