The efficient coding hypothesis posits that sensory systems are tuned to the regularities of their natural input. The statistics of natural image databases have been the topic of many studies, which have revealed biases in the distribution of orientations that are related to neural representations as well as behavior in psychophysical tasks. However, commonly used natural image databases contain images taken with a camera with a planar image sensor and limited field of view. Thus, these images do not incorporate the (...) physical properties of the visual system and its active use reflecting body and eye movements. Here, we investigate quantitatively, whether the active use of the visual system influences image statistics across the visual field by simulating visual behaviors in an avatar in a naturalistic virtual environment. Images with a field of view of 120° were generated during exploration of a virtual forest environment both for a human and cat avatar. The physical properties of the visual system were taken into account by projecting the images onto idealized retinas according to models of the eyes' geometrical optics. Crucially, different active gaze behaviors were simulated to obtain image ensembles that allow investigating the consequences of active visual behaviors on the statistics of the input to the visual system. In the central visual field, the statistics of the virtual images matched photographic images regarding their power spectra and a bias in edge orientations toward cardinal directions. At larger eccentricities, the cardinal bias was superimposed with a gradually increasing radial bias. The strength of this effect depends on the active visual behavior and the physical properties of the eye. There were also significant differences between the upper and lower visual field, which became stronger depending on how the environment was actively sampled. Taken together, the results show that quantitatively relating natural image statistics to neural representations and psychophysical behavior requires not only to take the structure of the environment into account, but also the physical properties of the visual system, and its active use in behavior. (shrink)

This paper documents a conversation between a philosopher and a human computer interaction researcher whose research has been enormously influenced by Wittgenstein. In particular, the in vivo use of categories in the design of communications and AI technologies are discussed, and how this meaning needs to evolve to allow creative design to flourish. The paper will be of interest to anyone concerned with philosophical tools in everyday action.

BackgroundAlthough the number of reporting guidelines has grown rapidly, few have gone through an updating process. The STARD statement (Standards for Reporting Diagnostic Accuracy), published in 2003 to help improve the transparency and completeness of reporting of diagnostic accuracy studies, was recently updated in a systematic way. Here, we describe the steps taken and a justification for the changes made.ResultsA 4-member Project Team coordinated the updating process; a 14-member Steering Committee was regularly solicited by the Project Team when making critical (...) decisions. First, a review of the literature was performed to identify topics and items potentially relevant to the STARD updating process. After this, the 85 members of the STARD Group were invited to participate in two online surveys to identify items that needed to be modified, removed from, or added to the STARD checklist. Based on the results of the literature review process, 33 items were presented to the STARD Group in the online survey: 25 original items and 8 new items; 73 STARD Group members (86 %) completed the first survey, and 79 STARD Group members (93 %) completed the second survey.Then, an in-person consensus meeting was organized among the members of the Project Team and Steering Committee to develop a consensual draft version of STARD 2015. This version was piloted in three rounds among a total of 32 expert and non-expert users. Piloting mostly led to rewording of items. After this, the update was finalized. The updated STARD 2015 list now consists of 30 items. Compared to the previous version of STARD, three original items were each converted into two new items, four original items were incorporated into other items, and seven new items were added.ConclusionsAfter a systematic updating process, STARD 2015 provides an updated list of 30 essential items for reporting diagnostic accuracy studies. (shrink)

The anthology contains twenty-two essays and is divided into two parts. The essays are, in the main, critical responses to aspects of what has come to be known in action theory as the ‘Standard View’ – the view that traces back to Donald Davidson's contribution to twentieth-century philosophy of action. The view under criticism treats actions as bodily movements caused in a non-deviant way by belief–desire pairs, construes these belief–desire pairs as the primary reasons for the actions that they cause, (...) and embraces event-causality.The issue of how we should conceive of action is taken up in several essays. For example: in Essay 1, Fred Dretske challenges the view that actions are external events that are the effect of the reasons for which the action is done. In Essay 16, Helen Steward, proposes that, instead of treating the availability of a reason-giving explanation as essential to action, we should construe action as ‘an exercise of the power of bodily control by an animal’. In Essay 21, Jonathan Dancy argues for a deflationary approach to actions, which forgoes treating actions ‘as individuals, with identity conditions’.Other authors – for example, Stephen Everson, Rowland Stout and Maria Alvarez – focus on the issue of what reasons for action are. Are they psychological states, or propositions, or states of affairs? Also under review is how to distinguish different kinds of reason: normative and explanatory reasons, and even explanatory and motivating reasons. (shrink)

A tight control of intracellular [Ca2+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{2+}$$\end{document}] is essential for the survival and normal function of cells. In this study we investigate key mechanistic steps by which calcium is regulated and calcium oscillations could occur using in silico modeling of membrane transporters. To do so we give a deterministic description of intracellular Ca2+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{2+}$$\end{document} dynamics using nonlinear dynamics in order to understand Ca2+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} (...) \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{2+}$$\end{document} signaling. We first present the ordinary differential equations system for cell calcium kinetics and make a preliminary work on Sobol indices. We then describe and analyze complex transporters action. Besides, we analyze the whole system. We finally perform numerical simulations and compare our results to real data. (shrink)

Is knowledge-how, or “practical” knowledge, a species of knowledge-that, or “theoretical” knowledge? There is no comfortable position to take in the debate around this question. On the one hand, there are counterexamples against the anti-intellectualist thesis that practical knowledge is best analysed as an ability. They show that having an ability to ϕ is not necessary for knowing how to ϕ. On the other hand, the intellectualist analysis of practical knowledge as a subspecies of theoretical knowledge is threatened by its (...) own set of counterexamples, which convincingly establish that practical knowledge lacks many of the typical characteristics of theoretical knowledge. Most strikingly it does not even appear to require a belief. In this paper, I develop an account of practical knowledge that avoids these counterexamples. It also manages to preserve both the status of such knowledge as a cognitive achievement and its apparently close conceptual relation to abilities. I start with the counterexamples against the necessity of abilities for practical knowledge and show that they fail because they underestimate the cognitive demands of attempts. I then make use of the logic of dispositions to bridge the gap that counterexamples against the necessity of abilities for practical knowledge open. It is argued that, instead of the ability to ϕ, it is a specific disposition to have the ability to ϕ that constitutes practical knowledge about ϕ. The resulting theory is an anti-intellectualist position that preserves essential intellectualist motivations and thus should be satisfactory for proponents of both views. (shrink)

This paper attempts to motivate the view that instead of rejecting modus ponens as invalid in certain situations, one could preserve its validity by associating such situations with non-normal interpretations of logical connectives.

Nostalgia, a sentimental longing for one’s past, can serve as a resource for individuals coping with discomforting experiences. The experience of bereavement poses psychological and physical risks....

Recent years have seen a high increase in the teaching of Philosophy in schools. Programs such as Pathways Schools in Australia International Society for Philosophers, since 2003), 'Philosophy in Schools' in the UK (Royal Institute of Philosophy, since 1999), and 'Philosophy for Children' in the USA, Australia, and the UK (International Council for Philosophical Inquiry since 1985 & Society for Advancing Philosophical Enquiry and Reflection in Education since 1993) are spreading around the world. Within a decade of its introduction Philosophy (...) (AS/A2) has become one of the most popular standard subjects taught across UK secondary.. (shrink)

Since its enactment in AD 313, the Edict of Milan, an edict that freed Christianity from empire-wide persecution, Constantine’s declaration has received a significant amount of attention within Christendom. Most of the discussion has centered on Constantine’s conversion, the precursor to the actual edict, with many suggesting that Constantine was acting more as a politician than a Christian. While this line of inquiry is legitimate, perhaps a better approach to the question may be more helpful to present-day Christians. That is, (...) while it is logical to deduce that every prudent politician will ignore the largest religious movement in his/her time at his/her own peril, Christians of every age will be better served if they critically evaluate their reception of each and every major policy that is clearly aimed at their benefit. With this background, this paper will attempt to critically examine the reception of Constantine’s edict by the Church in the years immediately following its enactment. Two early exhibits will be brought to bear here: the Donatist controversy and the Arian controversy. In so doing, the thesis that while Christians had every reason to celebrate the enactment of the edict, down the road, an uncritical adoption of the emperor’s policies and favors towards the church opened a door for an unhealthy marriage between earthly powers and the church that proved detrimental in the ensuing years, will be defended. As such, the Church’s reception of the Edict of Milan continues to be a lesson to Christians of every age in their relationship with the political leadership of their time. (shrink)

We argue that, if taken seriously, Kripke's view that a language for science can dispense with a negation operator is to be rejected. Part of the argument is a proof that positive logic, i.e., classical propositional logic without negation, is not categorical.

A system of logic usually comprises a language for which a model-theory and a proof-theory are defined. The model-theory defines the semantic notion of model-theoretic logical consequence (⊨), while the proof-theory defines the proof- theoretic notion of logical consequence (or logical derivability, ⊢). If the system in question is sound and complete, then the two notions of logical consequence are extensionally equivalent. The concept of full formalization is a more restrictive one and requires in addition the preservation of the standard (...) meanings of the logical terms in all the admissible interpretations of the logical calculus, as it is proof-theoretically defined. Although classical first-order logic is sound and complete, its standard formalizations fall short to be full formalizations since they allow non-intended interpretations. This fact poses a challenge for the logical inferentialism program, whose main tenet is that the meanings of the logical terms are uniquely determined by the formal axioms or rules of inference that govern their use in a logical calculus, i.e., logical inferentialism requires a categorical calculus. This paper is the first part of a more elaborated study which will analyze the categoricity problem from its beginning until the most recent approaches. I will first start by describing the problem of a full formalization in the general framework in which Carnap (1934/1937, 1943) formulated it for classical logic. Then, in sections IV and V, I shall discuss the way in which the mathematicians B.A. Bernstein (1932) and E.V. Huntington (1933) have previously formulated and analyzed it in algebraic terms for propositional logic and, finally, I shall discuss some critical reactions Nagel (1943), Hempel (1943), Fitch (1944), and Church (1944) formulated to these approaches. (shrink)

2020 is the year of the first pandemic lived through the Internet. More than half of the world population is now online and because of self-isolation, our moral and social lives unfold almost exclusively online. Two pressing questions arise in this context: how much can we rely on the Internet, as a set of technologies, and how much should we trust online platforms and applications? In order to answer these two questions, I develop an argument based on two fundamental assumptions: (...) the development stage of today’s Internet is a contingent and not a necessary one and technologies are never neutral. My argument is that today’s pandemic produced an acceleration of the change which started almost 30 years ago, one of online migration, datafication and algorithmization of day to day life, a change in which digital technologies take on the classic role of institutions, both formal and informal. My thesis is a descriptive one, although it has some normative implications: this take over is not just a translation, but a modification or mutation which demands a creative collective answer, although users don’t have direct power over it. When they play the role of institutions, these technologies are surrogates or simulacra. I offer the paradigmatic case of online education, an experiment we were forced into because of the pandemic, in order to show that the institutional matrix of education cannot be reproduced online, due to the limitations of the medium and of the applications, especially those concerning physical presence. In the end I will critically address the question of the role played by Artificial Intelligence in the pandemic, and then I will show that the open source ethics was more useful in approaching scientifically and technologically the problems generated by the epidemic. (shrink)

A Companion to the Philosophy of Action offers a comprehensive overview of the issues and problems central to the philosophy of action. The first volume to survey the entire field of philosophy of action (the central issues and processes relating to human actions). Brings together specially commissioned chapters from international experts. Discusses a range of ideas and doctrines, including rationality, free will and determinism, virtuous action, criminal responsibility, Attribution Theory, and rational agency in evolutionary perspective. Individual chapters also cover prominent (...) historic figures from Plato to Ricoeur. Can be approached as a complete narrative, but also serves as a work of reference. Offers rich insights into an area of philosophical thought that has attracted thinkers since the time of the ancient Greeks. (shrink)

A number of well-developed theories shed light on the question, under what circumstances our beliefs enjoy epistemic justification. Yet, comparatively little is known about epistemic defeat--when new information causes the loss of epistemic justification. This book proposes and defends a detailed account of epistemic defeaters. The main kinds of defeaters are analyzed in detail and integrated into a general framework that aims to explain how beliefs lose justification. It is argued that defeaters introduce incompatibilities into a noetic system and thereby (...) prompt a structured re-evaluation process that makes a justified reinstatement of the defeated belief impossible. The account is then applied to the topic of disagreement, where it is used in an argument for conciliationism, as well as a new explanation for higher-order defeat. Throughout the book, the notion of defeat is the center of attention, while a number of new issues are discussed at the intersections of defeat and justification. Specifically, new problems are raised for broadly internalist accounts of defeat, a fully descriptive reliabilist account of defeat is provided, and the case for normative defeat is revisited. (shrink)

The disposal of high-level radioactive waste (HLRW) is an issue that has seemed to defy not only solution but even a rational approach. This article reviews the development of U.S. HLRW disposal policy, focusing on the role of the scientific establishment. The failure of policymakers and their expert advisers is traced to the nature of the issues that need to be resolved to guarantee the safety of present and future generations. Scientific analysis cannot be used to predict the significance and (...) impact of human actions at disposal sites in the distant future. Consequently, it cannot provide a comprehensive risk assessment of any permanent HLRW disposal options. Perpetual management of HLRW in monitored retrievable facilities can address this issue. A management process that is guided by both science and ethics is best suited to protecting health and the environment, as well as intergenerational equity and justice. (shrink)