Promoting Charitable Behaviour with Compliance Techniques

Pour comparer l'impact de trois techniques d'acquiescement sur l'incitation au comportement charitable, on a demandéà 409 personnes de verser $2 à l'American Cancer Society. Cette requête fut immédiatement présentée dans trois groupes contrôle et précédée dans neuf groupes expérimentaux d'une demande préliminaire correspondant à une procédure d'acquiescement à requête multiple. On a d'abord demandé aux sujets soumis à la technique "pied dans la porte" de répondre à un questionnaire composé 10, 35 ou 60 items. On sollicitait d'abord $10, 25 ou 50 de la part de ceux confrontés à la situation "porte dans la figure"; et $0,50, 1 ou 1,50 de la part des sujets "ras des pâquerettes". Les résultats montrent que les méthodes $10 et 25 "porte dans la figure" furent les plus rentables. Les sujets contrôle et "ras des pâquerettes" donnèrent à peu près la même chose et les conditions "pied dans la porte" furent les moins productives. On discute, à partir de ces découvertes, de la valeur pratique et des inconvénients virtuels de l'application des techniques d'acquiescement à requête multiple pour stimuler le comportement charitable.     

Looking for long-term mnemonic effects on serial recall: the legacy of Simonides

We investigated three issues with respect to the long-term serial recall of adults. First, retention interval was manipulated to obtain uncontaminated measures of long-term serial recall. Second, we compared serial recall of concrete and abstract nouns to determine how these materials might interact with various learning strategies over time. Third, control group participants were asked to describe the learning strategies used, allowing a comparison of technical mnemonic techniques with the spontaneously generated strategies of adults. We found that the delayed recall performance of participants who spontaneously used organizational or imagery-based strategies was comparable to that of those instructed in the method of loci and pegword technique. Word concreteness did not interact with any other variable. These results are discussed with regard to their implications for serial learning in educational settings.     

Heading judgments in minimal environments: the value of a heuristic when invariants are rare

Observers made systematic heading judgments in two experiments simulating their translation through an environment with only two trees. When those trees converged or decelerated apart, observers tended to follow the invariant information and make heading judgments outside the near member of the pair. When those trees accelerated apart, however, observers tended to follow the heuristic information and make judgments outside the far member, although this result was tempered by the angular separation between the trees and their relative acceleration. The simultaneous existence and use of invariants and heuristics are discussed in terms of different metatheoretical approaches to perception.     

锌对细胞凋亡调控研究的一些思考

锌是机体必需的微量元素,它能够抑制细胞凋亡,也可以诱导细胞凋亡。阐述近年有关锌对细胞凋亡的研究结果,提出要全面,辩证地看待二者之间的关系。     

Using perfusion fMRI to measure continuous changes in neural activity with learning

In this study, we examine the suitability of a relatively new imaging technique, arterial spin labeled perfusion imaging, for the study of continuous, gradual changes in neural activity. Unlike BOLD imaging, the perfusion signal is stable over long time-scales, allowing for accurate assessment of continuous performance. In addition, perfusion fMRI provides an absolute measure of blood flow so signal changes can be interpreted without reference to a baseline. The task we used was the serial response time task, a sequence learning task. Our results show reliable correlations between performance improvements and decreases in blood flow in premotor cortex and the inferior parietal lobe, supporting the model that learning procedures that increase efficiency of processing will be reflected in lower metabolic needs in tissues that support such processes. More generally, our results show that perfusion fMRI may be applied to the study of mental operations that produce gradual changes in neural activity.     

Fruitful visual search: Inhibition of return in a virtual foraging task

Inhibition of return (IOR) has long been viewed as a foraging facilitator in visual search. We investigated the contribution of IOR in a task that approximates natural foraging more closely than typical visual search tasks. Participants in a fully immersive virtual reality environment manually searched an array of leaves for a hidden piece of fruit, using a wand to select and examine each leaf location. Search was slower than in typical IOR paradigms, taking seconds instead of a few hundred milliseconds. Participants also made a speeded response when they detected a flashing leaf that either was or was not in a previously searched location. Responses were slower when the flashing leaf was in a previously searched location than when it was in an unvisited location. These results generalize IOR to an approximation of a naturalistic visual search setting and support the hypothesis that IOR can facilitate foraging. The experiment also constitutes the first use of a fully immersive virtual reality display in the study of IOR.     

Automatic and effortful processing of self-statements in depression

Clark and Beck (1999) and Williams et al. (1997) have come up with quite different conclusions regarding which cognitive processes are most affected by negative self-schemata and negative knowledge structures. In order to increase the understanding of differences in effortful and automatic processing in depression, we compared never depressed (ND), previously depressed (PD) and clinically depressed (CD) individuals on free recall, recognition and fabrication of positive and negative self-statements. The results showed that: (i) overall NDs and PDs recalled more positive self-statements than CDs, whereas CDs correctly recognized more negative self-statements than NDs and PDs; and (ii) CDs and PDs fabricated more negative than positive self-statements, whereas no difference was obtained for NDs. The results seem to be in line with Clark and Beck's suggestions. However, there are several aspects of the present findings that make the picture more complicated.     

Traits and stories: links between dispositional and narrative features of personality

Dispositional traits and life narratives represent two different levels of personality that have not previously been empirically linked. The current study tested five hypotheses connecting Big-Five traits to life-narrative indices of emotional tone, theme, and structure. Students (Study 1) and adults (Study 2) completed a self-report measure of the Big-Five traits and provided extended written accounts of either ten (students) or eight (adults) key life-narrative scenes, including life high points, low points, and turning points. Content analysis of the narrative data revealed that for both samples Neuroticism was positively associated with an emotionally negative life-narrative tone, Agreeableness was correlated with narrative themes of communion (e.g., friendship, caring for others), and Openness was strongly associated with the structural complexity of life narrative accounts. Contrary to prediction, however, Conscientiousness was not consistently associated with themes of agency (e.g., achievement, self-mastery) and Extraversion was unrelated to positive narrative tone. The results are discussed in the context of contemporary research and theorizing on the narrative study of lives and the relation of narrative research in personality to more conventional, trait-based approaches.     

Between reality and imagination: when is spatial updating automatic?

Spatial updating has been shown to occur automatically and operate on both real and imagined environments. In three experiments, we compared spatial updating in real and imagined environments and examined when automatic spatial updating occurs. Participants learned the locations of real objects in a room and imagined being in their kitchens. They turned to face either the kitchen or the room targets and pointed to the targets before and after turning. Although objects in the real environment were automatically updated when the participants turned in the imagined environment, targets in the imagined environment were not automatically updated when the participants turned in the real environment. However, explicit spatial updating of imagined environments was as efficient as that of real environments. Automatic updating of the real objects required perceptual experience of these targets, either visually or by touch, and did not occur when the targets were described verbally. Implications for spatial cognition research are discussed.     

Examining Interindividual Differences in Cyclicity of Pleasant and Unpleasant Affects Using Spectral Analysis and Item Response Modeling

Weekly cycles in emotion were examined by combining item response modeling and spectral analysis approaches in an analysis of 179 college students' reports of daily emotions experienced over 7 weeks. We addressed the measurement of emotion using an item response model. Spectral analysis and multilevel sinusoidal models were used to identify interindividual differences in intraindividual cyclic change. Simulations and incomplete data designs were used to examine how well this combination of analysis techniques might work when applied to other practical data problems. Empirically, we found systematic individual differences in the extent to which individuals' emotions follow a weekly cycle, and in how such cycles are exhibited. Weekly cycles accounted for very little variance in day to day emotions at the individual level. Analytically, we illustrate how measurement, change, and interindividual difference models from different traditions may be combined in a practical manner to describe some of the complexities of human behavior. The authors gratefully acknowledge the support provided by grant T32 AG20500 from the National Institute on Aging in the preparation of this article. Special thanks to those at the Institute for Developmental and Health Research Methodology at the University of Virginia and to Paul De Boeck and the reviewers for helpful comments on earlier versions of this work.