Temporal learning in random control procedures

Experiments 1 and 2 delivered conditioned stimuli (CSs) at random times and unconditioned stimuli (USs) at either fixed (Experiment 1) or random (Experiment 2) intervals. In Experiment 3, CS duration was manipulated, and US deliveries occurred at random during the background. In all 3 experiments, the mean rate of responding (head entries into the food cup) in the background was determined by the mean US-US interval, and the mean rate during the CS was a linear combination of responding controlled by the mean US-US and mean CS onset-US intervals; the pattern of responding in time was determined by the interval distribution form (fixed or random). An event-based timing account, Packet theory, provided an explanation of the results.     

State and Trait Correlates of Job Performance: A Tale of Two Perspectives

The relative importance of dispositional and situational influences on organizational behaviors has been widely debated within the organizational sciences. In the current research, we report the results of two field studies that, taken together, provide an opportunity to examine the relative contributions of psychological well-being, positive mood, and negative mood as predictors of job performance. In Study 1, bivariate correlational analyses demonstrated that psychological well-being and negative mood, but not positive mood, were related to job performance measured over the past year. Hierarchical regression analysis found that psychological well-being was positively related to job performance, even when controlling for positive and negative mood. These findings were replicated and extended in the second study. In particular, bivariate correlational analyses demonstrated that psychological well-being and negative mood were predictive of job performance at the present time. However, unlike Study 1, hierarchical regression analyses found that both psychological well-being and negative mood were predictive of performance, even after controlling for each other and positive mood.     

Cellular mechanisms underlying neuronal excitability during morphine withdrawal in physical dependence: lessons from the magnocellular oxytocin system

Opiates are used clinically as analgesics, but their euphoric actions can lead to continued use and to dependence and addiction. While there are many factors involved in drug abuse, avoidance of stressful withdrawal symptoms is a key feature of addiction and its treatment. Fundamental to this is the need to understand the cellular processes that induce dependence and lead to the withdrawal syndrome. Many neurones in the brain express opioid receptors but only a few types of neurone develop dependence during chronic morphine exposure. The physiology of opiate-dependent cells is altered such that they require the continued presence of the drug to function normally and this is revealed, in cells that are inhibited by initial acute exposure to opiate, by a rebound hyperexcitation upon opiate withdrawal. Hypothalamic oxytocin neurones robustly develop morphine dependence and provide an exceptional opportunity to probe the cellular mechanisms underlying morphine dependence and withdrawal excitation. Although expression of morphine withdrawal excitation by oxytocin cells requires afferent inputs, the underlying mechanisms appear to reside within the oxytocin neurones themselves and probably involve changes in the intrinsic membrane properties of these neurones.     

The ghost condition: imitation versus emulation in young children's observational learning

Although observational learning by children may occur through imitating a modeler's actions, it can also occur through learning about an object's dynamic affordances--a process that M. Tomasello (1996) calls "emulation." The relative contributions of imitation and emulation within observational learning were examined in a study with 14- to 26-month-old children. The effectiveness of a "ghost" condition, in which the effective operation of the means apparatus was seen to occur without human agency, was compared with that of a standard modeling procedure in which the child saw an experimenter demonstrate the means action. The ghost condition was as likely to encourage observational learning as was the modeling condition; indeed, performance in the ghost condition was significantly better. The role of emulation in the development of observational learning is discussed in the context of a possible form of goal directedness without agency.     

Are facial displays social? Situational influences in the attribution of emotion to facial expressions

Observers are remarkably consistent in attributing particular emotions to particular facial expressions, at least in Western societies. Here, we suggest that this consistency is an instance of the fundamental attribution error. We therefore hypothesized that a small variation in the procedure of the recognition study, which emphasizes situational information, would change the participants' attributions. In two studies, participants were asked to judge whether a prototypical "emotional facial expression" was more plausibly associated with a social-communicative situation (one involving communication to another person) or with an equally emotional but nonsocial, situation. Participants were found more likely to associate each facial display with the social than with the nonsocial situation. This result was found across all emotions presented (happiness, fear, disgust, anger, and sadness) and for both Spanish and Canadian participants.     

Familiarity, ambivalence, and firm reputation: is corporate fame a double-edged sword?

This research questioned the proposition that corporate familiarity is positively associated with firm reputation. Student images of familiar and unfamiliar Fortune 500 corporations were examined in 4 experiments. The results suggested that, consistent with behavioral decision theory and attitude theory, highly familiar corporations provide information that is more compatible with the tasks of both admiring and condemning than less familiar corporations. Furthermore, the judgment context may determine whether positive or negative judgments are reported about familiar companies. The notion that people can simultaneously hold contradictory images of well-known firms may help to explain the inconsistent findings on the relation between familiarity and reputation.     

The role of perceptual load in processing distractor faces

It has been established that successful ignoring of irrelevant distractors depends on the extent to which the current task loads attention. However, the previous load studies have typically employed neutral distractor stimuli (e.g., letters). In the experiments reported here, we examined whether the perception of irrelevant distractor faces would show the same effects. We manipulated attentional load in a relevant task of name search by varying the search set size and found that whereas congruency effects from meaningful nonface distractors were eliminated by higher search load, interference from distractor faces was entirely unaffected by search load. These results support the idea that face processing may be mandatory and generalize the load theory to the processing of meaningful and more complex nonface distractors.     

Direct and moderating effects of community context on the psychological well-being of African American women

The effects of community characteristics on well-being were examined among 709 African American women. Direct and moderating effects of neighborhood characteristics on distress were tested. Aggregate-level ratings of neighborhood cohesion and disorder were significantly related to distress, although the relation between cohesion and distress became nonsignificant when individual risk factors were statistically controlled. Aggregate-level neighborhood variables interacted significantly with individual risk and resource variables in the prediction of distress, consistent with trait-situation interaction theories (D. Magnusson & N. S. Endler, 1977). Community cohesion intensified the benefits of a positive life outlook. Community disorder intensified both the benefits of personal resources and the detrimental effects of personal risk factors. Results showed evidence of resilience among African American women.