A quintessential challenge for any perceptual system is the need to focus on task-relevant information without being blindsided by unexpected, yet important information. The human visual system incorporates several solutions to this challenge, one of which is a reflexive covert attention system that is rapidly responsive to both the physical salience and the task-relevance of new information. This paper presents a model that simulates behavioral and neural correlates of reflexive attention as the product of brief neural attractor states that are (...) formed across the visual hierarchy when attention is engaged. Such attractors emerge from an attentional gradient distributed over a population of topographically organized neurons and serve to focus processing at one or more locations in the visual field, while inhibiting the processing of lower priority information. The model moves towards a resolution of key debates about the nature of reflexive attention, such as whether it is parallel or serial, and whether suppression effects are distributed in a spatial surround, or selectively at the location of distractors. Most importantly, the model develops a framework for understanding the neural mechanisms of visual attention as a spatiotopic decision process within a hierarchy and links them to observable correlates such as accuracy, reaction time, and the N2pc and PD components of the EEG. This last contribution is the most crucial for repairing the disconnect that exists between our understanding of behavioral and neural correlates of attention. (shrink)

Las 15 piezas que ahora lo conforman abrevan en la Historia, en confeciones personales y entrevistas, y mezclan la literatura y el periodismo de manera audaz y perfecta. Los protagonistas son hombres excepcionales y el momento que se ha elegido para contar son las visperas de sus muertes -tal vez el momento de mayor soledad y de mayor intimidad de un hombre. A traves de la magistral escritura de Tomas Eloy Martinez tenemos el privilegio de asistir a los ultimos minutos (...) de sus vidas, el momento previo a perderlo todo y cuando, resistiendo a la indiferencia del mundo, se suena con alguna inmortalidad. (shrink)

In this article we aim to reconstruct some aspects of Davidson's idea of triangulation, and against this reconstruction, ask whether the idea is viciously circular. We begin by looking at the claim that without a triangularn setting, there is no saying what the cause of a being's responses is. In the first section we discuss the notion of relevant similarity, and what difference the presence of a second non‐linguistic being could make for the individuation of a common focus of attention. (...) In the second section we look at the role of a second person in language‐acquisition. It is important that being corrected to ‘go on as others do’ does not yet presuppose thought, and similarity standards can be applied to a learner's reactions even before she is aware of these standards. We also show why Davidson is not committed to any consensus view of correctness. In the last section we discern three charges of circularity that can be levelled against the idea of triangulation. We argue that Davidson can respond to the first two charges, and point to a way of answering the third. But the response we propound raises a new question, namely, why does the second being have to be a speaker or thinker even before the learner is aware of the three points of the triangle? (shrink)

The March 2002 symposium Human Dignity and Reproductive Technology brought together philosophers, theologians, scientists, lawyers, and scholars from across the United States. The essays of this book are the contributions of the symposium's participants.

1. Escritos doctrinales -- 2. Escritos histórico-filosóficos.

In early April 1911 Albert Einstein arrived in Prague to become full professor of theoretical physics at the German part of Charles University. It was there, for the first time, that he concentrated primarily on the problem of gravitation. Before he left Prague in July 1912 he had submitted the paper "Relativität und Gravitation: Erwiderung auf eine Bemerkung von M. Abraham" in which he remarkably anticipated what a future theory of gravity should look like. At the occasion of the Einstein-in-Prague (...) centenary an international meeting was organized under a title inspired by Einstein's last paper from the Prague period: "Relativity and Gravitation, 100 Years after Einstein in Prague". The main topics of the conference included: classical relativity, numerical relativity, relativistic astrophysics and cosmology, quantum gravity, experimental aspects of gravitation, and conceptual and historical issues. The conference attracted over 200 scientists from 31 countries, among them a number of leading experts in the field of general relativity and its applications. This volume includes abstracts of the plenary talks and full texts of contributed talks and articles based on the posters presented at the conference. These describe primarily original results of the authors. Full texts of the plenary talks are included in the volume "General Relativity, Cosmology and Astrophysics--Perspectives 100 Years after Einstein in Prague", editions. J. Bičák and T. Ledvinka, published also by Springer Verlag. (shrink)

A más de cien años de su nacimiento y casi treinta de su muerte, Paul Grice sigue siendo uno de los filósofos más citados, discutidos e incomprendidos del siglo xx. Innovador, desafiante e inconforme intelectualmente, parece haber llevado a cabo uno de los anhelos más profundos de la filosofía oxoniense del lenguaje ordinario: transformar la reflexión sobre el lenguaje en una reflexión sobre la acción humana. El libro argumenta a favor de esta tesis señalando cómo algunos problemas específicos de la (...) filosofía del lenguaje de Grice sólo pueden ser tratados en el contexto de sus reflexiones más maduras sobre acción, racionalidad y valor. Defiende también la posición de que muchas explicaciones de significado son lógicamente análogas a las explicaciones de la acción. Pero la evaluación de la acción en términos de las razones involucra al menos dos tipos de restricciones racionales: aquellas internas al hablante (lo que resulta racional para él) y otras externas (lo que el hablante debe hacer desde el punto de vista de los demás). Con su celebrado análisis del significado del hablante, Grice enfatiza rasgos del primer tipo; con su famosa teoría de la conversación, identifica rasgos del segundo. Y ambos tipos de restricciones solo tienen sentido si se reconoce que el significado de una palabra o de una conducta no es una cosa ni una entidad mental sino la conformidad del símbolo o la acción con un criterio normativo. La conclusión general de Grice resuena más allá de sus contribuciones precursoras en filosofía del lenguaje y permite articular una posición metafísica. En un mundo sin seres capaces de evaluar, de dar y reconocer valor, la pregunta por el significado carecería de objeto. (shrink)

Los trabajos que aquí se presentan ofrecen una gran panorámica sobre la reflexión en torno a la vida humana y vienen a continuación de los expuestos en el libro Dimensiones de la vida humana tal como las ofrece la antropología española. Ahora se abordan esas dimensiones desde tres vertientes diferenciadas, la historia, la literatura y la hermenéutica. La vida humana es plural y así son también las vistas sobre ella. Un primer conjunto de textos trata de la imagen del ser (...) humano en diversos momentos de la historia de la filosofía. Un segundo grupo nos acerca a la reflexión filosófica que se da en la literatura, ya que los escritores exploran las posibilidades de la vida humana, con lo que sus creaciones son un excelente mirador que el antropólogo filósofo no puede ignorar. Por último aparece un bloque de investigaciones que se centran en la hermenéutica -con una importante presencia de Paul Ricoeur- y en M. Merleau-Ponty, con motivo de su centenario en 2008. La cantidad de trabajos aquí recogidos es una buena muestra de los estudios que sobre antropología filosófica se están realizando en nuestro país. Cada texto es una ventana abierta que permite una mirada sobre el ser humano, sobre su imagen o sus imágenes. Sobre los autores: Javier San Martín, catedrático de Filosofía en la UNED, ha centrado su investigación en la fenomenología, antropología filosófica y filosofía de Ortega y Gasset. Tomás Domingo Moratalla, profesor de Ética en la Universidad Complutense de Madrid, se ha centrado en la filosofía de Paul Ricoeur, la antropología filosófica y la filosofía práctica en clave hermenéutica. (shrink)

Proceeding from our absolute space-time conceptions, we obtain the formula for the gravitational frequency shift in an extremely simple way. Using our “burst” model for photons, we show that the different rates of clocks placed in spatial regions with different gravitational potentials appear as a direct result of the gravitational frequency shift and the axiomatic assumption that at any space point the time unit is to be defined by light clocks with equal “arms,” i.e., that at any space point the (...) light velocity (in moving frames the “there-and-back” velocity) has the same numerical valuec. Considering the principle of equivalence, we come to the logical conclusion that the kinematic (Einstein-Lorentz) time dilation is an absolute phenomenon. (shrink)

If phonons are particles, they must be attached to absolute space through their proper masses, which depend on the absolute velocities. In such a case one should be able to register with phonons the Sagnac and Marinov effects which have been observed with massless and massive particles (photons and neutrons). The experimental possibilities for such experiments are analyzed.

Drawing out literal and metaphorical meanings of 'foreignness' this wide-ranging volume offers much to scholars of postcolonial, gender, and cultural studies seeking new approaches to the study of alterity.

In the light of our recently performed experiments, revealing the anisotropy of light velocity in any frame moving with respect to absolute space, we show that the Lorentz transformation, where the relativity of light velocity is given implicitly through the relativity of the time coordinates, must be treated from an absolute point of view if one seeks to preserve its adequacy to physical reality. Then we propose a new transformation (which is to be considered as a legitimate companion of the (...) Lorentz transformation) wherein the relativity of light velocity is given explicitly and the time coordinates are absolute. (shrink)

The article criticises the attempt to establish connectionism as an alternative theory of human cognitive architecture through the introduction of thesymbolic/subsymbolic distinction (Smolensky, 1988). The reasons for the introduction of this distinction are discussed and found to be unconvincing. It is shown that thebrittleness problem has been solved for a large class ofsymbolic learning systems, e.g. the class oftop-down induction of decision-trees (TDIDT) learning systems. Also, the process of articulating expert knowledge in rules seems quite practical for many important domains, (...) including common sense knowledge.The article discusses several experimental comparisons betweenTDIDT systems and artificial neural networks using the error backpropagation algorithm (ANNs usingBP). The properties of one of theTDIDT systemsID3 (Quinlan, 1986a) are examined in detail. It is argued that the differences in performance betweenANNs usingBP andTDIDT systems reflect slightly different inductive biases but are not systematic; these differences do not support the view that symbolic and subsymbolic systems are fundamentally incompatible. It is concluded, that thesymbolic/subsymbolic distinction is spurious. It cannot establish connectionism as an alternative cognitive architecture. (shrink)

We consider the historic Harress-Sagnac experiment in the light of our absolute space-time theory, proposing two modifications, and we give an account of its recent practical performance. We show that the effect of the rotating disk experiment is a direct result of the light velocity's direction dependence and we point out that our recently performed coupled-mirrors experiment, with whose help for the first time we have measured the Earth's absolute velocity, can be considered as a logical result of the rotating (...) disk experiment. (shrink)