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Experiments Used (experiment + used)
Selected AbstractsNeural correlates of successful and partial inhibitions in children: An ERP studyDEVELOPMENTAL PSYCHOBIOLOGY, Issue 7 2009Lucy Cragg Abstract This experiment used event-related potentials (ERPs) to investigate the neural processes underlying the development of response inhibition in a modified version of the go/no-go paradigm [Cragg and Nation [2008] Developmental Science 11(6): 819,827]. N2 and P3 ERP components on correct go trials and partial and successful inhibitions were compared in 7- and 9-year-old children. A larger N2 effect on successful inhibitions was found in 9-year-olds compared to 7-year-olds at fronto-central electrodes. N2 amplitude was positively related to behavioral performance in the 7-year-olds suggesting it may reflect inhibitory processes; however, this relationship was not present in the 9-year-olds. Age differences were also apparent in the go P3, perhaps indicating differences in stimulus processing. The no-go P3 component was larger on successful than partial inhibitions. In contrast, there was no difference in N2 amplitude between partial and successful inhibitions. A significant difference was found in N2 latency however. This suggests that inhibitory processes are similar in both cases but initiated earlier on successful inhibitions. N2 latency was also shorter in 9-year-olds than 7-year-olds supporting an increase in the efficiency of response inhibition with age. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 533,543, 2009. [source] NMR chemical shift measurements revisited: High precision measurementsCONCEPTS IN MAGNETIC RESONANCE, Issue 4 2007P. Granger Abstract Accurate chemical shifts are now accessible with high field NMR spectrometers. After the recall of the basic formulae, methods are proposed to measure chemical shifts with a high precision. Using two coaxial rotors at the magic angle, the necessary parameters used for correction are measured. The influence of different factors on the precision of the NMR measurements is discussed. Some proposals are given for MAS experiments used with solid-state samples. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 184,193, 2007. [source] Number sense in human infantsDEVELOPMENTAL SCIENCE, Issue 1 2005Fei Xu Four experiments used a preferential looking method to investigate 6-month-old infants' capacity to represent numerosity in visual-spatial displays. Building on previous findings that such infants discriminate between arrays of eight versus 16 discs, but not eight versus 12 discs (Xu & Spelke, 2000), Experiments 1 and 2 investigated whether infants' numerosity discrimination depends on the ratio of the two set sizes with even larger numerosities. Infants successfully discriminated between arrays of 16 versus 32 discs, but not 16 versus 24 discs, providing evidence that their discrimination shows the set-size ratio signature of numerosity discrimination in human adults, children and many non-human animals. Experiments 3 and 4 addressed a controversy concerning infants' ability to discriminate large numerosities (observed under conditions that control for total filled area, array size and density, item size and correlated properties such as brightness: Brannon, 2002; Xu, 2003b; Xu & Spelke, 2000) versus small numerosities (not observed under conditions that control for total contour length: Clearfield & Mix, 1999). To investigate the sources of these differing findings, Experiment 3 tested infants' large-number discrimination with controls for contour length, and Experiment 4 tested small-number discrimination with controls for total filled area. Infants successfully discriminated the large-number displays but showed no evidence of discriminating the small-number displays. These findings provide evidence that infants have robust abilities to represent large numerosities. In contrast, infants may fail to represent small numerosities in visual-spatial arrays with continuous quantity controls, consistent with the thesis that separate systems serve to represent large versus small numerosities. [source] The conjunction fallacy: explanations of the linda problem by the theory of hintsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 1 2003Hans Wolfgang Brachinger Empirical research has shown that in some situations, subjects tend to assign a probability to a conjunction of two events that is larger than the probability they assign to each of these two events. This empirical phenomenon is traditionally called the conjunction fallacy. One of the best-known experiments used to demonstrate the conjunction fallacy is the Linda problem introduced by Tversky and Kahneman in 1982. They explain the "fallacious behavior" by their so-called judgemental heuristics. These heuristics have been criticized heavily as being far "too vague to count as explanations". In this article, it is shown that the "fallacious behavior" in the Linda problem can be explained by the so-called theory of hints. © 2003 Wiley Periodicals, Inc. [source] On the robustness and the direction of the effect of cause-related marketingJOURNAL OF CONSUMER BEHAVIOUR, Issue 4 2003Eldad Yechiam Abstract Two experiments are presented in this paper that explore the effect of cause-related marketing (CRM) on product choice. To allow evaluation of the effect of experience and the role of individual differences, the experiments used a repeated choice setting. The results of Experiment 1 showed that the effect of CRM was stable over time. However, the direction of the effect was sensitive to the value of the product. CRM served as an equaliser: it helped disadvantaged alternatives and reduced the attractiveness of superior alternatives. Experiment 2 showed that the effect of CRM decreased but did not disappear in an easy choice task. These findings are summarised in a simple model and discussed in terms of their potential marketing applications. Copyright © 2003 Henry Stewart Publications. [source] Recognizing large donations to public goods: an experimental testMANAGERIAL AND DECISION ECONOMICS, Issue 1 2002Jeremy Clark Private charities often publicise generous individual contributions or contributors, possibly to encourage others to give. In contrast, public good experiments used to study voluntary giving commonly tell participants only of total contributions. This paper reports an experimental test of the effect on contributions of supplying additional selective information. A control treatment is run that reveals only total contributions over ten one-shot decision rounds. This is compared to a second treatment that also informs subjects of the maximum contribution made in their group after each round. In a third treatment, subjects are further given the opportunity to make costly rewards to the maximum contributor. Revealing generous contributions appears to raise average contributions slightly. Surprisingly, adding the ability to reward large contributors does little to generate further increases, though it significantly raises the variance of contributions. Copyright © 2002 John Wiley & Sons, Ltd. [source] A review of in situ measurement of organic compound transformation in groundwater,,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2001Sharon K Papiernik Abstract Laboratory assessments of the rate of degradation of organic compounds in groundwater have been criticized for producing unrepresentative results. The potential for organic compounds to be transformed in groundwater has been measured using in situ methods, which avoid problems of attempting to duplicate aquifer conditions in the laboratory. In situ assessments of transformation rates have been accomplished using transport studies and in situ microcosms (ISMs); a review of these methods is given here. In transport studies, organic solutes are injected into an aquifer and the concentrations are monitored as they are transported downgradient. The change in mass of a solute is determined by the area contained under the breakthrough curve (plot of concentration versus time). ISMs isolate a portion of the aquifer from advective flow and act as in situ batch reactors. Experiments using ISMs involve removing water from the ISM, amending it with the solutes of interest, re-injecting the amended water, and monitoring the solute concentrations with time. In both transport and ISM studies, the loss of organic solutes from solution does not allow a distinction to be made between sorptive, abiotic and biotic transformation losses. Biological activity can be chemically suppressed in ISMs and the results from those experiments used to indicate sorption and abiotic loss. Transformation products may be monitored to provide additional information on transformation mechanisms and rates. Published in 2001 for SCI by John Wiley & Sons, Ltd [source] Design and Analysis of Arm-in-Cage Experiments: Inference for Three-State Progressive Disease Models with Common Periodic Observation TimesBIOMETRICS, Issue 2 2008B. A. Griffin Summary We develop statistical methods for designing and analyzing arm-in-cage experiments used to test the efficacy of insect repellents and other topical treatments. In these experiments, a controlled amount of the treatment is applied to a volunteer's forearm, which then is exposed to the insects by being placed into a special cage. Arms are not kept in the cages continuously, but rather placed there periodically for a brief period of time, during which it is noted whether an insect lands (but does not bite) or (lands and) bites. Efficacy of a repellent can be described using a progressive three-state model in which the first two states represent varying degrees of protection (no landing and landing without biting) and the third state occurs once protection is completely lost (biting). Because subjects within a treatment group follow the same cage visit schedule, transition times between states are interval censored into one of several fixed intervals. We develop an approach that uses a mixture of nonparametric and parametric techniques for estimating the parameters of interest when sojourn times are dependent. Design considerations for arm-in-cage experiments are addressed and the proposed methods are illustrated on data from a recent arm-in-cage experiment as well as simulated data. [source] | ||||||||||