Shepard has argued that a universal law should govern generalization across different domains of perception and cognition, as well as across organisms from different species or even different planets. Starting with some basic assumptions about natural kinds, he derived an exponential decay function as the form of the universal generalization gradient, which accords strikingly well with a wide range of empirical data. However, his original formulation applied only to the ideal case of generalization from a single encountered stimulus to a (...) single novel stimulus, and for stimuli that can be represented as points in a continuous metric psychological space. Here we recast Shepard's theory in a more general Bayesian framework and show how this naturally extends his approach to the more realistic situation of generalizing from multiple consequential stimuli with arbitrary representational structure. Our framework also subsumes a version of Tversky's set-theoretic model of similarity, which is conventionally thought of as the primary alternative to Shepard's continuous metric space model of similarity and generalization. This unification allows us not only to draw deep parallels between the set-theoretic and spatial approaches, but also to significantly advance the explanatory power of set-theoretic models. Key Words: additive clustering; Bayesian inference; categorization; concept learning; contrast model; features; generalization; psychological space; similarity. (shrink)

Exploring how people represent natural categories is a key step toward developing a better understanding of how people learn, form memories, and make decisions. Much research on categorization has focused on artificial categories that are created in the laboratory, since studying natural categories defined on high-dimensional stimuli such as images is methodologically challenging. Recent work has produced methods for identifying these representations from observed behavior, such as reverse correlation (RC). We compare RC against an alternative method for inferring the structure (...) of natural categories called Markov chain Monte Carlo with People (MCMCP). Based on an algorithm used in computer science and statistics, MCMCP provides a way to sample from the set of stimuli associated with a natural category. We apply MCMCP and RC to the problem of recovering natural categories that correspond to two kinds of facial affect (happy and sad) from realistic images of faces. Our results show that MCMCP requires fewer trials to obtain a higher quality estimate of people’s mental representations of these two categories. (shrink)

People are adept at inferring novel causal relations, even from only a few observations. Prior knowledge about the probability of encountering causal relations of various types and the nature of the mechanisms relating causes and effects plays a crucial role in these inferences. We test a formal account of how this knowledge can be used and acquired, based on analyzing causal induction as Bayesian inference. Five studies explored the predictions of this account with adults and 4-year-olds, using tasks in which (...) participants learned about the causal properties of a set of objects. The studies varied the two factors that our Bayesian approach predicted should be relevant to causal induction: the prior probability with which causal relations exist, and the assumption of a deterministic or a probabilistic relation between cause and effect. Adults’ judgments (Experiments 1, 2, and 4) were in close correspondence with the quantitative predictions of the model, and children’s judgments (Experiments 3 and 5) agreed qualitatively with this account. (shrink)

In many learning or inference tasks human behavior approximates that of a Bayesian ideal observer, suggesting that, at some level, cognition can be described as Bayesian inference. However, a number of findings have highlighted an intriguing mismatch between human behavior and standard assumptions about optimality: People often appear to make decisions based on just one or a few samples from the appropriate posterior probability distribution, rather than using the full distribution. Although sampling-based approximations are a common way to implement Bayesian (...) inference, the very limited numbers of samples often used by humans seem insufficient to approximate the required probability distributions very accurately. Here, we consider this discrepancy in the broader framework of statistical decision theory, and ask: If people are making decisions based on samples—but as samples are costly—how many samples should people use to optimize their total expected or worst-case reward over a large number of decisions? We find that under reasonable assumptions about the time costs of sampling, making many quick but locally suboptimal decisions based on very few samples may be the globally optimal strategy over long periods. These results help to reconcile a large body of work showing sampling-based or probability matching behavior with the hypothesis that human cognition can be understood in Bayesian terms, and they suggest promising future directions for studies of resource-constrained cognition. (shrink)

If Bayesian Fundamentalism existed, Jones & Love's (J&L's) arguments would provide a necessary corrective. But it does not. Bayesian cognitive science is deeply concerned with characterizing algorithms and representations, and, ultimately, implementations in neural circuits; it pays close attention to environmental structure and the constraints of behavioral data, when available; and it rigorously compares multiple models, both within and across papers. J&L's recommendation of Bayesian Enlightenment corresponds to past, present, and, we hope, future practice in Bayesian cognitive science.

Current psychological theories of human causal learning and judgment focus primarily on long-run predictions: two by estimating parameters of a causal Bayes nets, and a third through structural learning. This paper focuses on people’s short-run behavior by examining dynamical versions of these three theories, and comparing their predictions to a real-world dataset.

The tendency to test outcomes that are predicted by our current theory (the confirmation bias) is one of the best-known biases of human decision making. We prove that the confirmation bias is an optimal strategy for testing hypotheses when those hypotheses are deterministic, each making a single prediction about the next event in a sequence. Our proof applies for two normative standards commonly used for evaluating hypothesis testing: maximizing expected information gain and maximizing the probability of falsifying the current hypothesis. (...) This analysis rests on two assumptions: (a) that people predict the next event in a sequence in a way that is consistent with Bayesian inference; and (b) when testing hypotheses, people test the hypothesis to which they assign highest posterior probability. We present four behavioral experiments that support these assumptions, showing that a simple Bayesian model can capture people's predictions about numerical sequences (Experiments 1 and 2), and that we can alter the hypotheses that people choose to test by manipulating the prior probability of those hypotheses (Experiments 3 and 4). (shrink)

This paper relates to a formal statement of the mechanisms that are thought minimally necessary to underpin consciousness. This is expressed in the form of axioms. We deem this to be useful if there is ever to be clarity in answering questions about whether this or the other organism is or is not conscious. As usual, axioms are ways of making formal statements of intuitive beliefs and looking, again formally, at the consequences of such beliefs. The use of this style (...) of exposition does not entail a claim to provide a mathematically rigorous formal deductive system. Conventional mathematical notation is used to achieve clarity, although this is elaborated with natural language in an attempt to reduce terseness. In our view, making the approach axiomatic is synonymous with building clear usable tests for consciousness and is therefore a central feature of the paper. The extended scope of this approach is to lay down some essential properties that should be considered when designing machines that could be said to be conscious. In the broader discussion about the nature of consciousness and its neurological mechanisms, it may seem to some that axiomatisation is premature and continues to beg many questions. However, the approach is meant to be open- ended so that others can build further axiomatic clarifications that address the very large number of questions which, in the search for a formal basis for consciousness, still remain to be answered. Of course, in discussions about consciousness many will also argue that the subject is not one that may ever be formally addressed by means of axioms. The view taken in this paper is 'let's try to do it and see how far it gets'. (shrink)

L B Daniels; Some Comments on ‘Value in Education’ by Johanna Burgess1, Journal of Philosophy of Education, Volume 8, Issue 2, 30 May 2006, Pages 237–250, https.

Since the role of the Asian countries is increasing in the modern world, their philosophical traditions attract more and more attention. Due to this trend, a more complete panoramic view of the development of world philosophy as a whole is accessible, and it has become possible to understand that any constructions of the human mind that have arisen in a particular cultural field of experience cannot be regarded as exemplary and absolute. The researchers of Asian philosophies concentrate mostly on studying (...) the texts of individual thinkers. As a rule, they do not set themselves the task of examining these texts from the point of view of intercultural interactions and transformations of significant ideas and concepts in various cultural and historical contexts, defining the direction and mechanisms of cultural borrowing, as well as revealing new approaches and growth points. To achieve these goals, the research should focus at the problem of the self-determination and development of philosophy as a separate science in non-Western cultures, which are based on intellectual traditions with different origin than Greek and Judeo-Christian traditions. This article deals with the consideration of some topics that elucidate the features of the development of philosophical science in Japan, including the emergence of the concept of “philosophy” in this country, the definition of its subject, the formation of philosophical terminology, and various interpretations of what the term “Japanese philosophy” means. The author pays special attention to the characteristic of the main periods of progress of Japanese philosophical thought. In the conclusion, the author argues that the most important characteristic feature of the Japanese philosophy is its involvement in intercultural dialogue throughout its history. (shrink)

ABSTRACTEmotional distractors can impair perception of subsequently presented targets, a phenomenon called emotion-induced blindness. Do emotional distractors lose their power to disrupt perception when appearing with increased frequency, perhaps due to desensitisation or enhanced recruitment of proactive control? Non-emotional tasks, such as the Stroop, have revealed that high frequency distractors or conflict lead to reduced interference, and distractor frequency appears to modulate attentional capture by emotional distractors in spatial attention tasks. But emotion-induced blindness is thought to reflect perceptual competition between (...) targets and emotional distractors, and it is unclear whether high frequency emotional stimuli cause less disruption at this relatively early stage of processing. In four experiments, participants searched streams of images for a rotated target image. A negative or neutral distractor appeared before the target, and their relative frequency was manipulated. Across all exper... (shrink)

Recent work in the ontology of music suggests that we will avoid confusion if we distinguish between two kinds of question that are typically posed in music ontology. Thus, a distinction has been made between fundamental ontology and higher-order ontology. The former addresses questions about the basic metaphysical options from which ontologists choose. For instance, are musical works types, indicated types, classes of particulars, or some other kind of entity? Higher-order ontology addresses the question of what lies ‘at the centre’ (...) of a specific form of music, such as rock or jazz—or perhaps classical music. The argument of this essay is, first, that a close examination of the best efforts in two of these territories shows that they have the effect of pressing the music in each sphere into implausible Procrustean beds. Second, it is argued that the general question that higher-order ontologies pose, that is, ‘What work-kind is it that lies at the centre of a given kind of music, F?’ is a question based on a mistaken but seductive assumption, namely that the concept of the work of F has actual application. In fact, these concepts—upon which higher-order ontology depends—are mere artefacts of philosophy. The question is also addressed why the assumption is so seductive. Finally, the question finally is posed about what, if anything, is implied from the foregoing about the traditional ontology of classical music. (shrink)

The aim of the study was to determine the acceptance and perception of Nigerian patients to medical photography. A self-administered questionnaire was distributed among Nigerian patients attending oral and maxillofacial surgery and plastic surgery clinics of 3 tertiary health institutions. Information requested included patients' opinion about consent process, capturing equipment, distribution and accessibility of medical photographs. The use of non-identifiable medical photographs was more acceptable than identifiable to respondents for all purposes (P = 0.003). Most respondents were favourably disposed to (...) photographs being taken for inclusion in the case note, but opposed to identifiable photographs being used for other purposes most especially in medical websites and medical journals. Female respondents preferred non-identifiable medical photographs to identifiable ones (P = 0.001). Most respondents (78%) indicated that their consent be sought for each of the outline needs for medical photography. Half of the respondents indicated that identifiable photographs may have a negative effect on their persons; and the most commonly mentioned effects were social stigmatization, bad publicity and emotional/psychological effects. Most of the respondents preferred the use of hospital-owned camera to personal camera/personal camera-phone for their medical photographs. Most respondents (67.8%) indicated that they would like to be informed about the use of their photographs on every occasion, and 74% indicated that they would like to be informed of the specific journal in which their medical photographs are to be published. In conclusion, non-identifiable rather than identifiable medical photography is acceptable to most patients in the studied Nigerian environment. The use of personal camera/personal camera-phone should be discouraged as its acceptance by respondents is very low. Judicious use of medical photography is therefore advocated to avoid breach of principle of privacy and confidentiality in medical practice. (shrink)

In Virgil's third eclogue, the goatherd Menalcas responds to his challenger Damoetas by offering as his wager in their contest of song a pair of embossed cups,caelatum diuini opus Alcimedontis, decorated with a pattern of vine and ivy. In the middle of this design, he says, are two figures. One is the astronomer Conon, and the other—at this point Menalcas, afflicted with a sudden loss of memory, professes to have forgotten the name of the second figure, and breaks off into (...) a question :quis fuit alter, | descripsit radio totum qui gentibus orbem, | tempora quae messor, quae curuus arator haberet?Various candidates for the identity of this second astronomer have been suggested, one of the most favoured being Eudoxus of Cnidus, whosePhaenomenahad been versified by the Hellenistic poet Aratus. In 1930 it was proposed by Léon Herrmann that Menalcas in fact answers his own question in his reference tocuruUS ARAToratEcl.3.42: the solution to Virgil's riddle is already written into the question, in the form of the anagram ofAratusconcealed within these two words. Strictly speaking, Hermann notes only that ‘Aratorau v. 42 évoque le nom d’Aratos’; he and later exponents of the theory tend to ignore the preceding ‘-us’—but there seems no reason to exclude it if an allusion to the Greek poet is to be seen in the two following syllables. (shrink)

Virgil's fourth Eclogue is one of the most quoted, adapted and discussed works of classical literature. This study traces the fortunes of Eclogue 4 in the literature and art of the Italian Renaissance. It sheds new light on some of the most canonical works of Western art and literature, as well as introducing a large number of other, lesser-known items, some of which have not appeared in print since their original publication, while others are extant only in manuscript. Individual chapters (...) are devoted to the uses made of the fourth Eclogue in the political panegyric of Medici Florence, the Venetian Republic and the Renaissance papacy, and to religious appropriations of the Virgilian text in the genres of epic and pastoral poetry. The book also investigates the appearance of quotations from the poem in fifteenth- and sixteenth-century fresco cycles representing the prophetic Sibyls in Italian churches. (shrink)

The paper illustrates how organic chemists dramatically altered their practices in the middle part of the twentieth century through the adoption of analytical instrumentation - such as ultraviolet and infrared absorption spectroscopy and nuclear magnetic resonance spectroscopy - through which the difficult process of structure determination for small molecules became routine. Changes in practice were manifested in two ways: in the use of these instruments in the development of 'rule-based' theories; and in an increased focus on synthesis, at the expense (...) of chemical analysis. These rule-based theories took the form of generalizations relating structure to chemical and physical properties, as measured by instrumentation. This 'Instrumental Revolution' in organic chemistry was two-fold: encompassing an embrace of new tools that provided unprecedented access to structures, and a new way of thinking about molecules and their reactivity in terms of shape and structure. These practices suggest the possibility of a change in the ontological status of chemical structures, brought about by the regular use of instruments. The career of Robert Burns Woodward (1917-1979) provides the central historical examples for the paper. Woodward was an organic chemist at Harvard from 1937 until the time of his death. In 1965, he won the Nobel Prize in Chemistry. (shrink)

An enormous amount of philosophical literature gets published nowadays. Some of it is good; some is fit only for pulping. We get into the habit not so much of reading as of glancing through the torrent that pours down on us. But sometimes special conditions arise. It so happened that I was forced to spend about a month in the hospital. I took with me the book Evolutionary Epistemology and the Logic of the Social Sciences: K. Popper and His Critics (...) [Evoliutsionnaia epistemologiia i logika sotsial'nykh nauk. K. Popper i ego kritiki] . I attentively read it through and without any irony I can say that I felt "legitimate pride and deep satisfaction." Legitimate pride for philosophy and deep satisfaction with the content of the book. And although readers of Problems of Philosophy [Voprosy filosofii] have already had the opportunity of reading a review of this book , I would like to return to it and make in passing a number of points about Popper's philosophy in general. (shrink)