Showing papers by "University of Western Ontario published in 1978"
660 citations
TL;DR: In this paper, it is shown that there is no compelling support for Piaget's hypothesis that cognitive stages do more than describe age-related changes in behavior, and they cannot be regarded as unique to the given stages for which they are posited.
Abstract: The term “stage” appears to be used in three general senses in theories of behavioral development: (a) as a metaphor: (b) as a description of behaviors that undergo age change; (c) as an explanation of age-related changes in behavior. Although most existing stage models are purely descriptive, a few of them purport to have explanatory power. One such model, Piaget's stages of cognitive development, is considered in this paper.To be viewed as potentially explanatory, a stage model must describe some behaviors that undergo age change, posit antecedent variables believed to cause the changes, and provide procedures whereby the behavioral changes and the antecedent variables can be independently measured. Piaget's stages seem to satisfy some but not all of these requirements. Piaget's stages describe many agerelated changes in behavior, and some antecedent variables have been proposed. However, procedures do not exist for measuring the two factors independently. In lieu of such procedures, Piaget has outlined a “program” of five empirical criteria whereby the reality of his stages can ostensibly be verified. Some objections to these criteria are considered.The five criteria in Piaget's program are invariant sequence, cognitive structure, integration, consolidation, and equilibration. Three of the criteria (invariant sequence, integration, and consolidation) lead to the same sorts of empirical predictions (culturally universal sequences in the acquisition of certain behaviors). Such predictions are subject to the objection that Piagetian invariant sequences are often measurement sequences. A measurement sequence is said to occur when some late-appearing behavior consists of some earlier-appearing behavior plus additional things. The cognitive structure criterion is subject to at least three criticisms: First, it yields, at most, descriptions of behavior; second, these are often nothing more than descriptions of task structure; third, they cannot be regarded as unique to the given stages for which they are posited. The fifth criterion, equilibration, generates some predictions that might be considered as prima facie evidence for the existence of stages. However, these predictions conflict with the current data base on Piaget's stages.It is concluded that there is no compelling support for Piaget's hypothesis that his cognitive stages do more than describe age-related changes in behavior. Since explanatory statements involving stages appear with some regularity in Piagetian and neo-Piagetian writings, there are grounds for supposing this conclusion to be nontrivial.
476 citations
TL;DR: In this article, the authors investigated the resistance of soil to harmonic motion of an infinitely long cylinder in terms of linear viscoelasticity and obtained a closed-form solution from which the complex stiffness can be evaluated.
Abstract: Resistance of soil to harmonic motion of an infinitely long cylinder is investigated theoretically in terms of linear viscoelasticity. Closed-form solution is obtained from which the complex stiffness can be evaluated. The numerical results agree with those obtained by means of the correspondence principle.
400 citations
TL;DR: The metallothioneins may also have an important role in regulating the normal absorption and homeostasis of zinc and copper as discussed by the authors, however, it is paradoxical, in that a protein synthesized within the cell to reduce toxicity, may, in itself, be toxic when excreted or leaked out from a cell to the extracellular space.
390 citations
TL;DR: The intestinal adaptive response to iron deficiency in both experimental animals and human subjects leads to the increased absorption of cadmium, a potentially toxic element.
381 citations
TL;DR: This paper examined whether modifying a message about a stimulus person to suit the listener has a lasting effect on the communicator's own recall and evaluation of this person and found that participants who actually wrote a message included many more positive labels and details in their message when the message recipient liked (versus disliked) the stimulus person.
352 citations
01 Jan 1978
300 citations
TL;DR: In this article, it is suggested that massive mixing processes occur near the base of the continental crust when mantle magmas are ponded near the Moho interface and this process is responsible for the general geochemistry of granitic magmas.
292 citations
TL;DR: The notable similarities of both such orders of predilection to the well-recognized “selective vulnerability” of certain hippocampal neurones in clinical conditions of hypoxia, ischemia and epilepsy suggest some common, focally accentuated cytotoxic mechanism may underlie all these regional predispositions.
Abstract: Topographic analysis was performed of the distribution of Alzheimer's neurofibrillary tangles and the granulovacuolar degeneration of Simchowicz in the hippocampal cortex of patients with Alzheimer's dementia and mentally normal aged controls. A semiautomated scanning stage microscope was linked potentiometrically to an XY pen recorder in order to plot cytoarchitectonic “scattergrams” from the sequentially screened hippocampal formations. The density of both lesions per cubic mm of pyramidal cortex was quantified by measuring the area of each of six “zones”, using a digitizer and programmable calculator. In elderly normal brains as well as those of Alzheimer's disease, the statistically most representative ranking order of predilection forneurofibrillary tangles (in decreasing severity) was: entorhinal cortex > subiculum > H1 > end-plate > presubiculum > H2. Forgranulovacuolar degeneration the best rank order was: subiculum > H1 > H2 > end-plate > entorhinal cortex > presubiculum. The notable similarities of both such orders of predilection to the well-recognized “selective vulnerability” of certain hippocampal neurones in clinical conditions of hypoxia, ischemia and epilepsy suggest some common, focally accentuated cytotoxic mechanism may underlie all these regional predispositions.
244 citations
TL;DR: A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior and found increased information acquisition was related to the product's importance for the individual.
Abstract: A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior. Findings included: (1) the mean proportion of availab...
241 citations
TL;DR: In this paper, a method for the numerical calculation of Fourier transforms in variables that are the logarithms of the original variable and transform variable is described, which can also be applied to Bessel and spherical Bessel transforms.
TL;DR: Results obtained using EPR spectroscopy indicate that, in phosphatidylcholine bilayers at physiological pH, ganglioside oligosaccharide chains are quite mobile and show a measurable tendency towards cooperative interaction amongst themselves, and that laterally mobile carbohydrate-bearing components of cell surface will show a tendency to cluster about complex glycoprotein arrays.
TL;DR: In this paper, a petrogenetic grid for plagioclase, spinel- and garnet-lherzolite analogues in the system CaO-MgO-Al2O3-SiO2 is presented from 1 bar to 30 kbar and 400 to 1500°C.
TL;DR: Discriminant analysis showed that most individual speakers of a tone language (Thai or Yoruba) can be easily distinguished from speaker of a nontone language (English) on the basis of their distinctive patterns of perceptual saliency for these five dimensions.
Abstract: Using an individual differences multidimensional scaling model of perception, this crosslanguage investigation seeks to determine what dimensions underlie the perception of linguistic tone, and to what extent an individual's language background (Thai, Yoruba or American English) influences his perception. Dissimilarities data were obtained from subjects' paired-comparison judgments of 13 different pitch patterns superimposed on a synthetic speech-like syllable. A multidimensional scaling analysis of the data for the total group revealed that five dimensions - interpretively labeled, AVERAGE PITCH, DIRECTION, LENGTH, EXTREME ENDPOINT and SLOPE - best summarize the perceptual structure underlying the dissimilarities data. Language subgroup variation in relative importance of these dimensions appears to be primarily related to subgroup differences in the way pitch is used to convey linguistic information. Discriminant analysis showed that most individual speakers of a tone language (Thai or Yoruba) can be ea...
TL;DR: It was indicated that visual cues, but not olfactory or auditory cues, played a critical role in the rat’s ability to avoid previously entered alleys and there was evidence also that rats used internal cues from kinesthetic and/or vestibular receptors when visual cues were absent.
Abstract: Rats were given three stages of training on an eight-arm, elevated radial maze with food reward at the end of each arm. In Stage 1, rats were allowed to choose freely among the arms from the beginning of a trial. In Stage 2, three initial forced choices were followed by a series of free choices. In Stage 3, the central platform of the maze was rotated with the rat on it between the initial forced choices and the free choices. Following testing on these three stages, the animals were divided into four groups and deprived of selected senses. One group was made blind, a second anosmic, a third blind and anosmic, and a fourth was left normal. The same three stages of testing that had been conducted preoperatively then were run again post-operatively. Throughout these tests, the possible use of auditory cues was tested by presenting white noise on alternate trials. Finally, two further tests were carried out, the multiple rotations test and the removal-replacement test. The results indicated that visual cues, but not olfactory or auditory cues, played a critical role in the rat’s ability to avoid previously entered alleys. There was evidence also that rats used internal cues from kinesthetic and/or vestibular receptors when visual cues were absent.
TL;DR: In this paper, a univariate logistic distribution can be specified by considering a suitable form for the odds in favor of a failure against survival, and a class of distributions, indexed by a parameter of association, having given marginals is proposed.
TL;DR: It is concluded that halothane selectively impairs two ventilatory responses mediated by peripheral chemoreceptors in man.
Abstract: To elucidate the effects of halothane on chemical regulation of ventilation in man, the authors studied the ventilatory responses to isocapnic hypoxia and hyperoxic hypercapnia in 33 human subjects while fully conscious and during sedation or anesthesia with halothane, .1, 1.1, or 2 MAC. In each group, the ventilatory effect of intravenous administration of doxapram, .4 mg/kg, was also measured. Halothane, 1.1 and 2 MAC, totally abolished the hypoxic response and nearly abolished the response to doxapram, while leaving the response to CO2 relatively brisk. Halothane, .1 MAC, decreased the responses to hypoxia and doxapram to less than a third of control, but did not alter the response to C02. It is concluded that halothane selectively impairs two ventilatory responses mediated by peripheral chemoreceptors in man.
TL;DR: In this paper, an approximate analytical solution is established that makes it possible to calculate impedance functions (stiffness and damping) of a single pile embedded in layered media, where the pile can be of stepwise variable cross section and feature any tip condition.
Abstract: An approximate analytical solution is established that makes it possible to calculate impedance functions (stiffness and damping) of a single pile embedded in layered media. The pile can be of stepwise variable cross section and feature any tip condition. The impedance functions are complex and frequency dependent but can be obtained by means of a computer program that is simple and very inexpensive to run. A comparison of the theory with experiments indicates the potential of the theory and demonstrates the need to consider the variation of soil properties with depth and lack of the fixity of the tip for short piles.
01 Mar 1978
TL;DR: In this paper, a theoretical model based on the assumption of a static quenching arising from B molecules located at distances between σ and σ′ from A* was proposed.
Abstract: Analysis of decay curves of electronically excited molecules A* versus time in presence of quencher B leads to the determination of kinetic data for the reaction (i.e. for diffusion limited reactions, the experimental collisional distance σ′ greater than the true collisional distance σ) and the sum D of diffusion coefficients of both reactants). Experimental fluorescence steady state measurements (Stern-Volmer representation) are inconsistent with calculated curves using classical Smoluchowski's model with σ′and D. The difference between this has been interpreted by complex formation in the ground state between A and B. But, this assumption is unnecessary if we take into account a “static” quenching arising from B molecules located at distances between σ and σ′ from A*. A theoretical model based upon this principle is described; good agreement between the model and experimental results was obtained.
TL;DR: The results support the idea that a diffuse ascending system from the brain stem is capable of producing two pharmacologically distinct forms of RSA and LVFA, and this neurochemical specificity may be established above thebrain stem.
TL;DR: It is argued that the traditional distinction between artificial intelligence and cognitive simulation amounts to little more than a difference in style of research - a different ordering in goal priorities and different methodological allegiances.
Abstract: It is argued that the traditional distinction between artificial intelligence and cognitive simulation amounts to little more than a difference in style of research - a different ordering in goal priorities and different methodological allegiances. Both enterprises are constrained by empirical considerations and both are directed at understanding classes of tasks that are defined by essentially psychological criteria. Because of the different ordering of priorities, however, they occasionally take somewhat different stands on such issues as the power/generality trade-off and on the relevance of the sort of data collected in experimental psychology laboratories.Computational systems are more than a tool for checking the consistency and completeness of theoretical ideas. They are ways of empirically exploring the adequacy of methods and of discovering task demands. For psychologists, computational systems should be viewed as functional models quite independent of (and likely not reducible to) neurophysiological systems, and cast at a level of abstraction appropriate for capturing cognitive generalizations. As model objects, however, they do present a serious problem of interpretation and communication since the task of extracting the relevant theoretical principles from a large complex program may be formidable.Methodologies for validating computer programs as cognitive models are briefly described. These may be classified as intermediate state, relative complexity, and component analysis methods. Compared with the constraints imposed by criteria such as sufficiency, breadth, and extendability, these experimentally based methods are relatively weak and may be most useful after some top-down progress is made in the understanding of methods sufficient for relevant tasks - such as may be forthcoming from artificial intelligence research.
TL;DR: For instance, ElDER et al. as discussed by the authors found that children under 3 years of age were most dependent on the presence of substitute objects which resembled their referents. But 3-year-old children were able to pretend equally well in all of the substitution conditions.
Abstract: ELDER, JOY L., and PEDERSON, DAVD R. Preschool Children's Use of Objects in Symbolic Play. CGrme DEVELOPMENT, 1978, 49, 500-504. Developmental differences in children's reliance on the presence of a substitute object and in the importance of similarity between the substitute object and its referent were investigated. Children at 3 age levels (2%, 3, and 312 years of age) were asked to perform actions under 1 of 3 substitution conditions: (1) with similar substitute objects whose general physical dimensions were similar to those of the reference objects; (2) with dissimilar substitute objects, which were physically unlike the referent objects and had their own particular use; or (3) with no object present. The results indicated that children under 3 years of age were most dependent on the presence of substitute objects which resembled their referents. 3%-year-old children were able to pretend equally well in all of the substitution conditions.
TL;DR: In this paper, a technique is discussed which enables extreme wind speed probabilities in mixed wind climates to be determined, and it is shown that in such wind climates the method is likely to yield more accurate probability estimates than the traditional Gumbel analysis of annual wind speed maxima, particularly for annual probabilities of less than 2%.
TL;DR: It is suggested that blood mercury levels can be used as a index of recent exposure, while urinary levels may be an index of renal concentration of mercury, because there is no reliable index for mercury concentration in the brain.
Abstract: The distribution of mercury in red blood cells (RBCs) and plasma, and its excretion in urine and feces are described in five human subjects during the first 7 days following inhalation of radioactive mercury vapor. A major portion (98%) of radioactive mercury in whole blood is initially accumulated in the RBCs and is transferred partly to the plasma compartment until the ratio of mercury in RBCs to plasma is about 2 within 20 hr. The cumulative urinary and fecal excretion of mercury for 7 days is about 11.6% of the retained dose, and is closely related to the percent decline in body burden of mercury. There is little correlation between either the urinary excretion and plasma radioactivity of mercury, or the specific activities of urine and plasma mercury, suggesting a mechanism other than a direct glomerular filtration involved in the urinary excretion of recently exposed mercury. These studies suggest that blood mercury levels can be used as an index of recent exposure, while urinary levels may...
TL;DR: The cellular source and gonadotropic control of follicular 17β-estradiol secretion were investigated and thecal preparations secreted relatively low amounts of estradiol in the absence of exogenous testosterone and somewhat higher quantities in its presence.
Abstract: The cellular source and gonadotropic control of follicular 17β-estradiol secretion were investigated. Theca and granulosa isolated from proestrous follicles of immature rats treated with pregnant mare's serum gonadotropin were cultured separately for 3 days in the presence or absence of LH (0.1 μg/ml), FSH (0.1 μg/ml), and/or testosterone (5 × 10-7 M). Medium was collected and replaced at 3, 6, 12, 24, 48, and 72 h of culture and measured for estradiol by radioimmunoassay. Granulosa cell cultures secreted negligible quantities of estradiol in the absence of exogenous androgen precursor. Addition of testosterone to the culture medium greatly increased the production of estradiol by granulosa cells. Estradiol secretion was sustained throughout the 3-day culture period only if both testosterone and FSH were included in the culture medium. Thecal preparations secreted relatively low amounts of estradiol in the absence of exogenous testosterone and somewhat higher quantities in its presence. Gonadotropins had ...