1,721,113 research outputs found
Millisecond accuracy video display using OpenGL under Linux
Full text linkTo measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
Wall rock alteration accompanying Canadian Pre-Cambrian gold mineralization
No full textThesis: Ph. D., Massachusetts Institute of Technology, Department of Geology, 1935Vita.Includes bibliographical references.by Neil Stewart Beaton.Ph. D.Ph. D. Massachusetts Institute of Technology, Department of Geolog
A kinetic study of the reactions of 1:2-epoxyethylbenzene, 1:2-epony-3-phenylpropane and 1:2-cpnxy-3-phenoxypropane with a series of amines
No full textThe effect of category variability in perceptual categorization
Full text linkExemplar and distributional accounts of categorization make differing predictions for the classification of a critical exemplar precisely halfway between the nearest exemplars of 2 categories differing in variability. Under standard conditions of sequential presentation, the critical exemplar was classified into the most similar, least variable category, consistent with an exemplar account. However, if the difference in variability is made more salient, then the same exemplar is classified into the more variable, most likely category, consistent with a distributional account. This suggests that participants may be strategic in their use of either strategy. However, when the relative variability of 2 categories was manipulated, participants showed changes in the classification of intermediate exemplars that neither approach could account for
Dissimilarity is used as evidence of category membership in multidimensional perceptual categorization: a test of the similarity-dissimilarity generalized context model
Full text linkIn exemplar models of categorization, the similarity between an exemplar and category members constitutes evidence that the exemplar belongs to the category. We test the possibility that the dissimilarity to members of competing categories also contributes to this evidence. Data were collected from two 2-dimensional perceptual categorization experiments, one with lines varying in orientation and length and the other with coloured patches varying in saturation and brightness. Model fits of the similarity-dissimilarity generalized context model were used to compare a model where only similarity was used with a model where both similarity and dissimilarity were used. For the majority of participants the similarity-dissimilarity model provided both a significantly better fit and better generalization, suggesting that people do also use dissimilarity as evidence
A PC parallel port button box provides millisecond response time accuracy under Linux
Full text linkFor psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
sj-pdf-1-mrj-10.1177_00222437211070589 - Supplemental material for Default Effects of Credit Card Minimum Payments
No full textSupplemental material, sj-pdf-1-mrj-10.1177_00222437211070589 for Default Effects of Credit Card Minimum Payments by Hiroaki Sakaguchi, Neil Stewart, John Gathergood, Paul Adams, Benedict Guttman-Kenney, Lucy Hayes and Stefan Hunt in Journal of Marketing Research</p
Sequence effects in categorization of simple perceptual stimuli
Full text linkCategorization research typically assumes that the cognitive system has access to a (more or less noisy) representation of the absolute magnitudes of the properties of stimuli and that this information is used in reaching a categorization decision. However, research on identification of simple perceptual stimuli suggests that people have very poor representations of absolute magnitude information and that judgments about absolute magnitude are strongly influenced by preceding material. The experiments presented here investigate such sequence effects in categorization tasks. Strong sequence effects were found. Classification of a borderline stimulus was more accurate when preceded by a distant member of the opposite category than by a distant member of the same category. It is argued that this category contrast effect cannot be accounted for by extant exemplar or decision-bound models of categorization. The effect suggests the use of relative magnitude information in categorization. A memory and contrast model illustrates how relative magnitude information may be used in categorization
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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