On quasivarieties and varieties as categories

Finitary quasivarieties are characterized categorically by the existence of colimits and of an abstractly finite, regularly projective regular generator G. Analogously, infinitary quasivarieties are characterized: one drops the assumption that G be abstractly finite. For (finitary) varieties the characterization is similar: the regular generator is assumed to be exactly projective, i.e., hom(G, –) is an exact functor. These results sharpen the classical characterization theorems of Lawvere, Isbell and other authors.Supported by the Czech Grant Agency (Project 201/02/0148).Special issue of Studia Logica: Algebraic Theory of Quasivarieties Presented by M. E. Adams, K. V. Adaricheva, W. Dziobiak, and A. V. Kravchenko     

Limitations of the mnemonic-keyword method

The effectiveness of the mnemonic-keyword method was investigated in 4 experiments in which participants were required to learn the 1st-language (L1, Spanish) equivalents of a list of 30 2nd-language words (L2, Latin). Experiments 1 (adolescents) and 2 (adults) were designed to assess whether the keyword method was more effective than the rote method; the researcher supplied the keyword, and the participants were allowed to pace themselves through the list. Experiments 3 (adolescents) and 4 (adults) were similar to Experiments 1 and 2 except that the participants were also supplied with a drawing that illustrated the relationship between the keyword and the L1 target word. All the experiments were performed with groups of participants in their classrooms (i.e., not in a laboratory context). In all experiments, the rote method was significantly more effective than was the keyword method.     

Development of a Spanish version of the Participation Motivation Inventory for young competitive swimmers

The present study examined the validity of a Spanish version of the Participation Motivation Inventory, modified for swimming by Gould, Feltz, and Weiss in 1985, and investigated whether young swimmers differing in sex and age vary in their objectives for participation. Swimmers (204 boys and 224 girls, ranging in age from 8 to 22 years) were administered the inventory. Factor analysis with varimax rotation identified seven factors fairly consistent with previous research. Differences were found across age and sex. Females placed greater emphasis than males on Friendship and Fun and indicated lower importance rating to Status. Younger children (8-10 years) rated Fun/Friendship, Competition/Skills, Significant Others, and Status significantly higher in importance than did the other age groups.     

An associative framework for probability judgment: an application to biases

Three experiments show that understanding of biases in probability judgment can be improved by extending the application of the associative-learning framework. In Experiment 1, the authors used M. A. Gluck and G. H. Bower's (1988a) diagnostic-learning task to replicate apparent base-rate neglect and to induce the conjunction fallacy in a later judgment phase as a by-product of the conversion bias. In Experiment 2, the authors found stronger evidence of the conversion bias with the same learning task. In Experiment 3, the authors changed the diagnostic-learning task to induce some conjunction fallacies that were not based on the conversion bias. The authors show that the conjunction fallacies obtained in Experiment 3 can be explained by adding an averaging component to M. A. Gluck and G. H. Bower's model.     

Dogs (Canis familiaris) learn from their owners via observation in a manipulation task

Eighty-seven pet dogs (Canis familiaris) were involved in an experiment in which they had to solve a task to obtain a ball. After witnessing a full demonstration by their owner (10 times pushing the handle of the box, which released a ball), most dogs preferred to touch the handle sooner and more frequently in comparison with other parts of the box, and they used the handle to get the ball. In contrast, dogs in 3 control groups developed their own respective methods. The lack of emergence of the ball and playing after the demonstration did not affect the learning performance strongly. This suggests that in dogs the outcome of a demonstration plays only a restricted role in the manifestation of social learning.     

The early origins of goal attribution in infancy

We contrast two positions concerning the initial domain of actions that infants interpret as goal-directed. The 'narrow scope' view holds that goal-attribution in 6- and 9-month-olds is restricted to highly familiar actions (such as grasping). The cue-based approach of the infant's 'teleological stance', however, predicts that if the cues of equifinal variation of action and a salient action effect are present, young infants can attribute goals to a 'wide scope' of entities including unfamiliar human actions and actions of novel objects lacking human features. It is argued that previous failures to show goal-attribution to unfamiliar actions were due to the absence of these cues. We report a modified replication of Woodward (1999) showing that when a salient action-effect is presented, even young infants can attribute a goal to an unfamiliar manual action. This study together with other recent experiments reviewed support the 'wide scope' approach indicating that if the cues of goal-directedness are present even 6-month-olds attribute goals to unfamiliar actions.     

Pavlov in America: a heterodox approach to the study of his influence

This work presents a critical analysis of Pavlov's influence that goes beyond the conventional view: that which reduces his influence in American psychology to the behaviorism of Watson and Hull. In order to understand the nature of the Russian physiologist's influence in American psychology, we propose a distinction between three approaches to it: 1) the symbolic approach, on representing a model of the possibility of constructing an objective psychology; 2) the methodological approach, given the importance of the technique of conditional reflexes; and 3) the theoretical approach, which is derived from his theory of higher nervous activity. This perspective permits us to suggest that most of Pavlov's influence on behaviorism was of a symbolic and methodological nature--though the methodological influence also reached other authors that did not belong to the behaviorist traditions, as was the case of Mateer. As far as the theoretical influence is concerned, our work proposes that it is more visible in authors such as Gantt and Liddell, or even in authors such as Boldirev, Director of the Pavlovian Laboratory at the Battle Creek Sanitarium in Michigan. The case of Gantt is especially interesting because, in addition to his important contributions, he played an essential role in the foundation of the Pavlovian Society, and the journal Conditional Reflex. What our work proposes is that to understand the nature of Pavlov's influence in American psychology it is necessary to take into account the very characteristics of that psychology: its pragmatic interests, its methodological rigor, the dominant systems of neo-behavioral theory and the changes that occurred after the Second World War.     

Nyíri,J.C., Tradition and Individuality: Philosophical Essays, “Synthese Library”; Nyíri,Kristóf,A hagyomány filozófiája (The Philosophy of Tradition); Neumer,Katalin, Gondolkodás,beszéd, írás (Thought,Language, and Writing)

Studies in East European Thought -     

Interactive learning in the paradise fish (Macropodus opercularis): an ethological interpretation of the second-order conditioning paradigm

This study was aimed at the examination of ‘mental construction’ in paradise fish by interactive learning, which is suggested as an alternative hypothesis for backward or second-order conditioning. Avoidance of goldfish was established in paradise fish by presenting a harmless goldfish (a novel stimulus) after an aversive event (mild electric shocks) in the dark compartment of a shuttle tank. It was found that this avoidance depended on context pre-exposure. Experiment 1 was designed to study the effect of mild shocks on shuttling activity in a familiar context. Experiment 2 aimed at establishing fear-conditioning to the goldfish in a higher-order conditioning paradigm. In the course of training, unpaired stimuli were presented in the dark compartment of the shuttle tank in such a manner that the presentation of mild shocks (20 mA) preceded the encounter with a harmless fish (goldfish). Experiment 3 demonstrated the role of context pre-exposure in interactive learning. Results indicate that (1) while 60 mA shocks resulted in avoidance of the dark compartment, the 20 mA mild shocks affected exploratory behaviour; (2) after pre-exposure to the training environment, paradise fish avoided the dark compartment containing goldfish provided that subjects had previously encountered mild, explorative shocks there; (3) this conditioned fear, a ‘mental construction’ of a potential danger, was proved to be transferable to another context and was consequently aimed specifically at the goldfish, a living being, rather than the training context; (4) the pre-exposure to the shuttle tank was an important part of this training procedure, that is, only subjects habituated to the shuttle tank avoided the goldfish. Results are discussed in the framework of the Interactive Learning Hypothesis, which has been developed as an ethological approach to a higher-order conditioning paradigm. Received: 15 January 1999 / Accepted after revision: 18 August 1999     

The role of central and peripheral vision in postural control duringwalking

Three hypotheses have been proposed for the roles of central and peripheral vision in the perception and control of self-motion: (1) peripheral dominance, (2) retinal invariance, and (3) differential sensitivity to radial flow. We investigated postural responses to optic flow patterns presented at different retinal eccentricities during walking in two experiments. Oscillating displays of radial flow (0° driver direction), lamellar flow (90°), and intermediate flow (30°, 45°) patterns were presented at retinal eccentricities of 0°, 30°, 45°, 60°, or 90° to participants walking on a treadmill, while compensatory body sway was measured. In general, postural responses were directionally specific, of comparable amplitude, and strongly coupled to the display for all flow patterns at all retinal eccentricities. One intermediate flow pattern (45°) yielded a bias in sway direction that was consistent with triangulation errors in locating the focus of expansion from visible flow vectors. The results demonstrate functionally specific postural responses in both central and peripheral vision, contrary to the peripheral dominance and differential sensitivity hypotheses, but consistent with retinal invariance. This finding emphasizes the importance of optic flow structure for postural control regardless of the retinal locus of stimulation.