Effects of lesions of the dorsal noradrenergic bundle on successive discrimination in the rat

Male Sprague-Dawley rats were trained to bar-press for food reward on a successive discrimination involving periods of reward on a variable-interval (VI) 18-s schedule interspersed with periods of extinction. The two components of the schedule were signaled by a steady or a flashing light, counterbalanced between VI and extinction components. Confirming previous findings, the discrimination was easier when the flashing light signaled VI and the steady light signaled extinction, than with the reverse allocation of stimuli. This pattern of results is consistent with a dynamogenic effect of flashing light relative to steady light, facilitating discrimination when the flashing light signals the occasion to respond but impairing discrimination when this stimulus signals the occasion to withhold responding. Given this interpretation of performance in the successive discrimination task, it may be used to test three different hypotheses of the functions of the dorsal noradrenergic bundle (DB): that this subserves learning, selective attention, or behavioral inhibition plus arousal. To examine these hypotheses sham-operated animals were compared to animals in which hippocampal noradrenaline levels had been reduced by 98% and hypothalamic levels by 48% after injection into the DB of the catecholamine-specific neurotoxin, 6-hydroxy-dopamine. The lesioned animals responded more slowly than controls in VI components when these were signaled by the flashing light, and more rapidly than controls in extinction components when these were signaled by the steady light. In consequence, the discrimination was impaired only in the condition (flashing light signaling VI, steady light signaling extinction) which controls found easier. These results are in conflict with predictions from the learning and attentional hypotheses of DB function. They are consistent, however, with a model that attributes behavioral inhibitory functions to the DB projection to the septohippocampal system, and arousing functions to the DB projection to the hypothalamus.     

A catalog of Boolean concepts

Boolean concepts are concepts whose membership is determined by a Boolean function, such as that expressed by a formula of propositional logic. Certain Boolean concepts have been much studied in the psychological literature, in particular with regard to their ease of learning. But research attention has been somewhat uneven, with a great deal of attention paid to certain concepts and little to others, in part because of the unavailability of a comprehensive catalog. This paper gives a complete classification of Boolean concepts up to congruence (isomorphism of logical form). Tables give complete details of all concepts determined by up to four Boolean variables. For each concept type, the tables give a canonic logical expression, an approximately minimal logical expression, the Boolean complexity (length of the minimal expression), the number of distinct Boolean concepts of that type, and a pictorial depiction of the concept as a set of vertices in Boolean D-space. Some psychological properties of Boolean concepts are also discussed.     

Written Responses in a Musical Situation as a Function of the Stability of Emotional Behavior

The present study investigated the degree to which learning sets developed during formation of 20 successive concepts. Forty S s were evenly distributed among eight experimental conditions. Conditions compared were rule with attribute identification, conjunctive with disjunctive concepts, and random with ordered arrays of figures. Results showed that learning sets formed with rule identification for both conjunctive and disjunctive concepts, but not with attribute identification. Concepts were easier to learn when using systematic compared to random arrays of figures (of questionable significance), when forming conjunctive rather than disjunctive concepts (not significant), and when using rule identification instead of attribute identification. Procedural differences among studies in this area appear to be major contributors to differences among studies in the results found.     

The effect of categorisation on sensitivity to second-order relations in novel objects

Adults appear to be more sensitive to configural information, including second-order relations (the spacing of features), in faces than in other objects. Superior processing of second-order relations in faces may arise from our experience of identifying faces at the individual level of categorisation (eg Bob versus John) but other objects at the basic level of categorisation (eg table versus chair; Gauthier and Tarr, 1997 Vision Research 37 1673- 1682). We simulated this learning difference with novel stimuli (comprised of blobs) by having two groups view the same stimuli but learn to identify the objects only at the basic level (based on the number of constituent blobs) or at both the basic level and individual level (based on the spacing, or second-order relations, of the blobs) of categorisation. Results from two experiments showed that, after training, observers in the individual-level training group were more sensitive to the second-order relations in novel exemplars of the learned category than observers in the basic-level training group. This is the first demonstration of specific improvement in sensitivity to second-order relations after training with non-face stimuli. The findings are consistent with the hypothesis that adults are more sensitive to second-order relations in faces than in other objects, at least in part, because they have more experience identifying faces at the individual level of categorisation.     

Alternatives to the fixed-set model: A review of appraisal models of emotion

Over several decades, appraisal theory has emerged as a prominent theoretical framework explaining the elicitation and differentiation of emotions, and has stimulated a great deal of theorising and empirical research. Despite the large amount of research in this area, there are many aspects of appraisal theory and research that remain unclear or problematic. In this review, we identify a common assumption of many appraisal theories—the fixed appraisal set—and argue that this assumption, combined with a lack of explicit theorising about the predicted relationship between appraisals and emotions, leads to a lack of clarity in both appraisal models and the empirical testing of those models. We recommend that appraisal theorists move in a direction already taken by a small number of theorists, and adopt the starting assumption of a variable appraisal set. We further suggest that theories of concepts and categorisation may inform theorising about appraisal–emotion relationships.     

Once More Unto the Breach: Type B Physicalism,Phenomenal Concepts,and the Epistemic Gap

Type B, or a posteriori, physicalism is the view that phenomenal-physical identity statements can be necessarily true, even though they cannot be known a priori—and that the key to understanding their status is to understand the special features of our phenomenal concepts, those concepts of our experiential states acquired through introspection. This view was once regarded as a promising response to anti-physicalist arguments that maintain that an epistemic gap between phenomenal and physical concepts entails that phenomenal and physical properties are distinct. More recently, however, many physicalists have lost confidence in the view, and have proposed less promising defences of physicalism—or have become outright sceptical about its prospects. I argue here that these physicalists have underestimated the resources of Type B physicalism and are thereby retreating too quickly—or fighting battles that have already been won.     

Response times seen as decompression times in Boolean concept use

This paper reports a study of a multi-agent model of working memory (WM) in the context of Boolean concept learning. The model aims to assess the compressibility of information processed in WM. Concept complexity is described as a function of communication resources (i.e., the number of agents and the structure of communication between agents) required in WM to learn a target concept. This model has been successfully applied in measuring learning times for three-dimensional (3D) concepts (Mathy and Bradmetz in Curr Psychol Cognit 22(1):41-82, 2004). In this previous study, learning time was found to be a function of compression time. To assess the effect of decompression time, this paper presents an extended intra-conceptual study of response times for two- and 3D concepts. Response times are measured in recognition phases. The model explains why the time required to compress a sample of examples into a rule is directly linked to the time to decompress this rule when categorizing examples. Three experiments were conducted with 65, 49, and 84 undergraduate students who were given Boolean concept learning tasks in two and three dimensions (also called rule-based classification tasks). The results corroborate the metric of decompression given by the multi-agent model, especially when the model is parameterized following static serial processing of information. Also, this static serial model better fits the patterns of response times than an exemplar-based model.     

A simulation laboratory for statistics

In this paper, we describe a general purpose data simulator, Datasim, which is useful for anyone conducting computer-based laboratory assignments in statistics. Simulations illustrating sampling distributions, the central limit theorem, Type I and Type II decision errors, the power of a test, the effects of violating assumptions, and the distinction between orthogonal and non-orthogonal contrasts are discussed. Simulations illustrating other statistical concepts—partial correlation, regression to the mean, heteroscedasticity, the partitioning of error terms in splitplot designs, and so on—can be developed easily. Simulations can be assigned as laboratory exercises, or the instructor can execute the simulations during class, integrate the results into an ongoing lecture, and use the results to initiate class discussion of the relevant statistical concepts.     

Representing serial action and perception

This article presents a review on the representational base of sequence learning in the serial reaction time task. The first part of the article addresses the major questions and challenges that underlie the debate on implicit and explicit learning. In the second part, the informational content that underlies sequence representations is reviewed. The latter issue has produced a rich and equivocal literature. A taxonomy illustrates that substantial support exists for associations between successive stimulus features, between successive response features, and between successive response-to-stimulus compounds. We suggest that sequence learning is not predetermined with respect to one particular type of information but, rather, develops according to an overall principle of activation contingent on task characteristics. Moreover, substantiating such an integrative approach is proposed by a synthesis with the dual-system model (Keele, Ivry, Mayr, Hazeltine, & Heuer, 2003).     

Isolated and interrelated concepts

A continuum between purely isolated and purely interrelated concepts is described. Along this continuum, a concept is interrelated to the extent that it is influenced by other concepts. Methods for manipulating and identifying a concept’s degree of interrelatedness are introduced. Relatively isolated concepts can be empirically identified by a relatively large use of nondiagnostic features, and by better categorization performance for a concept’s prototype than for a caricature of the concept. Relatively interrelated concepts can be identified by minimal use of nondiagnostic features, and by better categorization performance for a caricature than for a prototype. A concept is likely to be relatively isolated when subjects are instructed to create images for their concepts rather than find discriminating features, when concepts are given unrelated labels, and when the categories that are displayed alternate rarely between trials. The entire set of manipulations and measurements supports a graded distinction between isolated and interrelated concepts. The distinction is applied to current models of category learning, and a connectionist framework for interpreting the empirical results is presented.     

Effects of partial symmetry, exposure time, and backward masking on judged goodness and reproduction of visual patterns

Six experiments investigated the effects of partial symmetry in visual patterns on judgement of pattern goodness, immediate memory, and learning. In Experiments 1—III pattern goodness ratings were substantially inter-correlated among a self-paced test condition and two conditions producing moderate to severe stimulus degradation (brief tachistoscopic exposure, and backward masking): the less the partial symmetry in a pattern, the lower was the judged goodness of the pattern. In Experiments IV and V immediate reproduction of patterns was observed respectively following exposures of 5-5000 ms, and backward masking. Correct reproduction improved with degree of partial symmetry. Concordant results were found in a free recall learning task (Experiment VI). Correlations between goodness and learning and memory performance for discrete patterns were always substantial. The results strongly suggest that pattern goodness can be appraised reliably and accurately with information processing times too short to permit pattern encoding in short-term visual memory. Evaluation of pattern goodness must therefore rest upon early (precategorical) processing of symmetry features.     

Intuition and Reasoning: A Dual-Process Perspective

A lay definition of intuition holds that it involves immediate apprehension in the absence of reasoning. From a more technical point of view, I argue also that intuition should be seen as the contrastive of reasoning, corresponding roughly to the distinction between Type 1 (intuitive) and Type 2 (reflective) processes in contemporary dual process theories of thinking. From this perspective, we already know a great deal about intuition: It is quick, provides feelings of confidence, can reflect large amounts of information processing, and is most likely to provide accurate judgments when based on relevant experiential learning. Unlike reasoning, intuition is low effort and does not compete for central working memory resources. It provides default responses which may—or often may not—be intervened upon with high effort, reflective reasoning. Intuition has, however, been blamed for a range of cognitive biases in the psychological literatures on reasoning and decision making. The evidence indicates that with novel and abstract problems, not easily linked to previous experience, intervention with effortful reasoning is often required to avoid such biases. Hence, although it seems that intuition dominates reasoning most of the time—both in the laboratory and the real world—it can indeed be a false friend.     

A Modular Neural Network Model of Concept Acquisition

Previous neural network models of concept learning were mainly implemented with supervised learning schemes. However, studies of human conceptual memory have shown that concepts may be learned without a teacher who provides the category name to associate with exemplars. A modular neural network architecture that realizes concept acquisition through two functionally distinct operations, categorizing and naming, is proposed as an alternative. An unsupervised algorithm realizes the categorizing module by constructing representations of categories compatible with prototype theory. The naming module associates category names to the output of the categorizing module in a supervised mode. In such a modular architecture, the interface between the modules can be conceived of as an “information relay” that encodes, constrains, and propagates important information. Five experiments were conducted to analyze the relationships among internal conceptual codes and simple conceptual and lexical development. The first two experiments show a prototype effect and illustrate some basic characteristics of the system. The third experiment presents a bottom-up model of the narrowing down of children's early lexical categories that honors mutual exclusivity. The fourth experiment introduces top-down constraints on conceptual coding. The fifth experiment exhibits how hierarchical relationships between concepts are learned by the architecture, and also demonstrates how a spectrum of conceptual expertise may gradually emerge as a consequence of experiencing more with certain categories than with others.     

Physiological activity in an attribute learning task.

The relationship between the amount of information processing in an Attribute Learning task and autonomic activity, measured by skin conductance response (SCR), was investigated. The amount of information processing was manipulated by type of concept and feedback. Furthermore, the influence of practice and verbalization was studied.Three types of concepts were used: conjunction, exclusion and joint denial. The stimulus population consisted of four three-valued dimensions. The results showed that (1) SCR did not differ among concepts; (2) SCR varied with type of feedback, it being smallest at blanks and largest at infirming feedback; (3) SCR was related to the number of confirmations preceding infirmation; (4) subjects mainly used the strategy ‘reject hypothesis only after infirmation’; (5) subjects usually selected not-yet-tested hypotheses; (6) practice influenced performance; (7) verbalization did not result in more efficient use of information; however, the appropriateness of the experimental set-up to study this factor was questioned; (8) conjunction was easier to learn than the other concepts. The results were discussed in terms of uncertainty reduction, resulting from testing hypotheses in a concept learning task.     

Making Connections: Categorisations and Particularisations in Students’ Literary Argument

This article investigates how students reason and argue to make sense of fictional literature. Excerpts from students’ talk are analysed using the concepts categorisation, particularisation and recontextualisation, and interpreted from a socio-cultural, dialogical perspective. The analyses show that the students’ arguments oscillate between personal experience and the novel, and between categorising and particularising perspectives. The subject relevance of talk that lies between everyday and scientific talk, and between personal and analytic readings, is revealed. The bridging of different readings, different language practices, and different learning contexts is discussed.     

Using Speakers' Referential Intentions to Model Early Cross-Situational Word Learning

ABSTRACT— Word learning is a "chicken and egg" problem. If a child could understand speakers' utterances, it would be easy to learn the meanings of individual words, and once a child knows what many words mean, it is easy to infer speakers' intended meanings. To the beginning learner, however, both individual word meanings and speakers' intentions are unknown. We describe a computational model of word learning that solves these two inference problems in parallel, rather than relying exclusively on either the inferred meanings of utterances or cross-situational word-meaning associations. We tested our model using annotated corpus data and found that it inferred pairings between words and object concepts with higher precision than comparison models. Moreover, as the result of making probabilistic inferences about speakers' intentions, our model explains a variety of behavioral phenomena described in the word-learning literature. These phenomena include mutual exclusivity, one-trial learning, cross-situational learning, the role of words in object individuation, and the use of inferred intentions to disambiguate reference.     

Iterating between lessons on concepts and procedures can improve mathematics knowledge

Background Knowledge of concepts and procedures seems to develop in an iterative fashion, with increases in one type of knowledge leading to increases in the other type of knowledge. This suggests that iterating between lessons on concepts and procedures may improve learning. Aims The purpose of the current study was to evaluate the instructional benefits of an iterative lesson sequence compared to a concepts‐before‐procedures sequence for students learning decimal place‐value concepts and arithmetic procedures. Samples In two classroom experiments, sixth‐grade students from two schools participated (N = 77 and 26). Method Students completed six decimal lessons on an intelligent‐tutoring systems. In the iterative condition, lessons cycled between concept and procedure lessons. In the concepts‐first condition, all concept lessons were presented before introducing the procedure lessons. Results In both experiments, students in the iterative condition gained more knowledge of arithmetic procedures, including ability to transfer the procedures to problems with novel features. Knowledge of concepts was fairly comparable across conditions. Finally, pre‐test knowledge of one type predicted gains in knowledge of the other type across experiments. Conclusions An iterative sequencing of lessons seems to facilitate learning and transfer, particularly of mathematical procedures. The findings support an iterative perspective for the development of knowledge of concepts and procedures.     

Distinctiveness and correlation in conceptual structure: behavioral and computational studies

Patients with category-specific deficits have motivated a range of hypotheses about the structure of the conceptual system. One class of models claims that apparent category dissociations emerge from the internal structure of concepts rather than fractionation of the system into separate substores. This account claims that distinctive properties of concepts in the living domain are vulnerable because of their weak correlation with other features. Given the assumption that mutual activation among correlated properties produces faster activation in the normal system, the authors predicted a disadvantage for the distinctive features of living things for unimpaired adults. Results of a speeded feature verification study supported this prediction, as did a computational simulation in which networks mapped from orthography to semantics.