The development of emergent differential sample behavior in pigeons

Three experiments attempted to replicate Manabe, Kawashima, and Staddon's (1995) finding of emergent differential sample behavior in budgerigars that has been interpreted as evidence of functional equivalence class formation. In Experiments 1 and 2, pigeons initially learned two-sample/ two-alternative matching to sample in which comparison presentation was contingent on pecking one sample on a differential-reinforcement-of-low-rate (DRL) schedule and the other on a fixed-ratio (FR) schedule. Later, two new samples were added to the task. Comparison presentation on these trials occurred after the first sample peck following a predetermined interval (Experiment 1) or after completion of either the DRL or FR requirement, whichever occurred first (Experiment 2). Experiment 1 found no evidence for emergent spaced versus rapid responding to the new samples as they established conditional control over the familiar choices. By contrast, differential responding did emerge for some pigeons in Experiment 2, with responding to each new sample coinciding with the pattern explicitly conditioned to the original sample occasioning the same comparison choice. This emergent effect, however, disappeared for most pigeons with continued training. Experiment 3 systematically replicated Experiment 2 using differential peck location as the sample behavior. Differential location pecking emerged to the new samples for most pigeons and remained intact throughout training. Our findings demonstrate a viable pigeon analogue to the budgerigar emergent calling paradigm and are discussed in terms of equivalence- and non-equivalence-based processes.     

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Key Word Index Volume 5     

Workload and burnout in nurses

This paper examines the relationship between workload, burnout and somatization in nurses. The respondents consisted of 1363 nurses employed in hospitals, which were undergoing extensive restructuring. Results of structural equation analyses showed that workload was positively related to emotional exhaustion. Emotional exhaustion led to cynicism and somatization, and cynicism was negatively related to nurses' professional efficacy. Implications of the results for nursing practice are discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Infants' interactions with professional caregivers at 3 and 6 months of age: a longitudinal study

This study longitudinally investigated the quality and stability of 64 infants’ interactions with their professional caregivers in child care centers at 3 and 6 months of age, i.e., across the first 3 months after they entered child care. It was also examined whether the infants’ negative emotionality (as rated by the mother) predicted the quality of the caregiver–infant interaction. The interactive behavior of the professional caregivers (sensitivity, cooperation) and the infants (responsiveness, involvement) was rated from videotapes recorded in three different caregiving situations, lasting about 25 min in total. In contrast to our expectation, the quality of the caregiver–infant interaction did not significantly increase across the first 3 months in child care. As expected, significant rank order stability was found for the quality of the caregivers’ behavior over time. Also in accordance with our expectations, infants with higher negative emotionality scores experienced less sensitivity and cooperation in interactions with their primary professional caregivers at both ages.     

Evidence against signal enhancement as a mechanism of direct selection by color

Two of the possible mechanisms that have been put forward to explain precuing effects are signal enhancement and uncertainty reduction. Signal enhancement leads to processing advantages for valid information because the signal at the known input channel is enhanced, whereas uncertainty reduction allows observers to ignore confusing distractor items in a display. Both mechanisms have been reported to be involved in location precuing, but it is still unclear which of these two mechanisms is responsible for color cuing effects. Two experiments are reported in which expectancy for a certain color in a single-item display was created. Targetswere presented briefly and were masked. If color cues produce signal enhancement, then a color cuing effect should result. If color cues only allow uncertainty reduction, however, there should be no color cuing effect because there are no distractors in single-item displays. The results of both experiments favor uncertainty reduction as the mechanism behind color cuing, because no signs of signal enhancement-based cuing effects were observed.     

Self-Reported Depression in Mothers of Children Who Have Experienced Sexual Abuse

The Beck Depression Inventory-II (BDI-II; A. T. Beck, R. A. Steer, & G. K. Brown, 1996) was administered to 164 biological mothers of sexually abused children to determine the psychometric characteristics of the BDI-II and to estimate the prevalence of self-reported depression in this population. The study also sought to ascertain whether the mothers’ BDI-II total scores were correlated with various psychosocial characteristics of the mothers and their children. It was found that there was only one dimension underlying the 21 BDI-II responses, and the internal consistency of the BDI-II total scores was high. Twenty-six percent of these mothers had scores indicative of clinical depression. The mothers’ BDI-II total scores were significantly correlated with their husbands’ or paramours’ having sexually abused their children and their ratings of the children’s internalizing behaviors. These results were discussed as supporting the use of the BDI-II with mothers of sexually abused children to measure self-reported depression.     

Business owners' action planning and its relationship to business success in three African countries

A model of business success was developed with motivational resources (locus of control, self-efficacy, achievement motivation, and self-reported personal initiative) and cognitive resources (cognitive ability and human capital) as independent variables, business owners' elaborate and proactive planning as a mediator, and business size and growth as dependent variables. Three studies with a total of 408 African micro and small-scale business owners were conducted in South Africa, Zimbabwe, and Namibia. Structural equation analyses partially supported the hypotheses on the importance of psychological planning by the business owners. Elaborate and proactive planning was substantially related to business size and to an external evaluation of business success and was a (partial) mediator for the relationship between cognitive resources and business success. The model carries important implications for selection, training, and coaching of business owners.     

Learning from experience: Bion's concept of reverie and Buddhist meditation: A comparative study

The author argues for a common denominator between Bion's view and the Buddhist view of mental development. In both thought systems, mental growth is synonymous to learning from experience. The author closely examines Bion's concept of attention and compares it to mindfulness, a major factor in Buddhist meditation. In both doctrines, attention must be isolated from other mental processes in order to attain learning from experience. The author compares reverie to the state of mind of equanimity. She argues that enhancement of the ability of reverie, or improving the inner container such that it can hold any content while unmoved by desire, is the purpose of Buddhist practice. Both view the mind as capable of transcending its own restrictions and 'the capacity to know anything' as attainable through disciplined practice.