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841.
What is the best account to explain the object-based attentional benefit—that is, the spread of attention within an attended object or prioritization of search across possible target locations within an attended object? Using a task in which the location of the target was known with certainty, in the present study we systematically manipulated the type (letters or bites) and the presentation time (long or short) of the target and flankers in order to test the effects of target–object integration and target presentation time on object-based attention. The results showed that an object-based effect could appear when the target was a bite, no matter whether the target presentation time was long or short; but when the target was a letter, an object-based effect was only observed when the target presentation time was short enough. These findings provide additional evidence supporting the argument of attentional spreading in object-based attention. However, this spreading is moderated jointly by target–object integration and the target presentation time. 相似文献
842.
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. 相似文献
843.
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. 相似文献
844.
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. 相似文献
845.
锌对细胞凋亡调控研究的一些思考 总被引:2,自引:0,他引:2
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。 相似文献
846.
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. 相似文献
847.
Thomas LE Ambinder MS Hsieh B Levinthal B Crowell JA Irwin DE Kramer AF Lleras A Simons DJ Wang RF 《Psychonomic bulletin & review》2006,13(5):891-895
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. 相似文献
848.
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. 相似文献
849.
Wang RF 《Perception & psychophysics》2004,66(1):68-76
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. 相似文献
850.
Nilam?RamEmail author Sy-Miin?Chow Ryan?P.?Bowles Lijuan?Wang Kevin?Grimm Frank?Fujita John?R.?Nesselroade 《Psychometrika》2005,70(4):773-790
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. 相似文献