The major theoretical framework relative to the perception of illusory figures is reviewed and discussed in the attempt to provide a unifying explanatory account for these phenomena.

Following the pioneering studies of the receptive field (RF), the concept gained further significance for visual perception by the discovery of input effects from beyond the classical RF. These studies demonstrated that neuronal responses could be modulated by stimuli outside their RFs, consistent with the perception of induced brightness, color, orientation, and motion. Lesion scotomata are similarly modulated perceptually from the surround by RFs that have migrated from the interior to the outer edge of the scotoma and in this way (...) provide filling-in of the void. Large RFs are advantageous to this task. In higher visual areas, such as the middle temporal and inferotemporal lobe, RFs increase in size and lose most of their retinotopic organization while encoding increasingly complex features. Whereas lowerlevel RFs mediate perceptual filling-in, contour integration, and figure–ground segregation, RFs at higher levels serve the perception of grouping by common fate, biological motion, and other biologically relevant stimuli, such as faces. Studies in alert monkeys while freely viewing natural scenes showed that classical and nonclassical RFs cooperate in forming representations of the visual world. Today, our understanding of the mechanisms underlying the RF is undergoing a quantum leap. What had started out as a hierarchical feedforward concept for simple stimuli, such as spots, lines, and bars, now refers to mechanisms involving ascending, descending, and lateral signal flow. By extension of the bottom-up paradigm, RFs are nowadays understood as adaptive processors, enabling the predictive coding of complex scenes. Top-down effects guiding attention and tuned to task-relevant information complement the bottom-up analysis. (shrink)

This major work covers almost all that has been learned about the acoustics of stringed instruments from Helmholtz's 19th-century theoretical elaborations to recent electroacoustic and holographic measurements.Many of the results presented here were uncovered by the author himself over a 20-year period of research on the physics of instruments in the violin family. Lothar Cremer is one of the world's most respected authorities on architectural acoustics and, not incidentally, an avid avocational violinist and violist.The book - which was published (...) in German in 1981 - first of all meets the rigorous technical standards of specialists in musical acoustics. But it also serves the needs and interests of two broader groups: makers and players of stringed instruments are expressly addressed, since the implications of the mathematical formulations are fully outlined and explained; and acousticians in general will find that the work represents a textbook illustration of the application of fundamental principles and up-to-date techniques to a specific problem.The first - and longest - of the book's three parts investigates the oscillatory responses of bowed strings. The natural nonlinearities that derive from considerations of string torsion and bending stiffness are deftly handled and concisely modeled.The second part deals with the body of the instrument. Special attention is given to the bridge, which transmits the oscillations of the strings to the wooden body and its air cavity. In this case, linear modeling proves serviceable for the most part - a simplification that would not be possible with lute - like instruments such as the guitar.The radiation of sound from the body into the listener's space, which is treated as an extension of the instrument itself, is the subject of the book's final part.Lothar Cremer is Professor Emeritus at the Technical University of Berlin, where he served as director of the Institute for Acoustical Engineering. (shrink)

I describe characteristic phenomena of quantum physics that suggest that reality appears to us in two domains: the open and well-known domain of empirical, material things—the realm of actuality—and a hidden and invisible domain of nonempirical, non-material forms—the realm of potentiality. The nonempirical forms are part of physical reality because they contain the empirical possibilities of the universe and can manifest themselves in the empirical world. Two classes of nonempirical states are discussed: the superposition states of microphysical entities, which are (...) nonempirical because observation destroys them, and the virtual states of material systems, which are nonempirical because they are empty. The non-empirical part to physical reality represents a predetermined and hidden order that exists before it is empirical, and the visible world is an emanation out of it. I discuss consequences for our understanding of human nature, the origin of life, and human values. Reality is an indivisible wholeness that is aware of its processes, like a Cosmic Spirit, and it reveals its awareness in the mindlike properties of elementary processes as well as in the human consciousness. Thus, one is led to G. W. F. Hegel's thesis that the Cosmic Spirit is thinking in us. (shrink)

Gilt das Verbot der Tötung Unschuldiger absolut oder darf selbst diese fundamentale Moralnorm unter Ausnahmebedingungen verletzt werden? Wir leben in einer Welt voller Gefahren. Das Leben von Menschen wird bedroht durch verbrecherische Diktaturen, terroristische Anschläge, technische Havarien und Katastrophen verschiedener Art. Dürfen solche Gefahren notfalls auch dann bekämpft werden, wenn dabei Unschuldige getötet werden oder ihr Tod in Kauf genommen werden muss? Das Buch gibt eine moralphilosophische Antwort auf diese politisch, ethisch und rechtlich umstrittene Frage. Lothar Fritze analysiert das (...) Rechtsdogma der Nichtabwägungsfähigkeit menschlichen Lebens und fragt, wie sich das Verbot der Tötung Unschuldiger mit der verbreiteten moralischen Intuition vereinbaren lässt, wonach in Extremfällen durchaus einige wenige unschuldige Menschen geopfert werden dürfen, um sehr viele andere Unschuldige zu retten. (shrink)

Modern science is based empirically on data, which are gained, mainly, by means of technical machinery and plants of high complexity. This type of laboratory research is at a distance to the old forms of investigating nature such that it is under suspicion to investigate artefacts rather than nature. - Against this it is argued in the following, that laboratory research has to be acknowledged as true heir of the form of science which Galileo had started. Knowledge of the powers (...) and mechanisms of nature can be gained only by means of pointed interventions into natural processes. The term ,,laboratory", however, designates less the place of experimentation, but, rather, the ,,thoughtstyle" practised by a research group, in which forms of handling experimental setups and (social) structures of cooperation in a team of specialists are integrated. - Scientific facts cannot be separated from the social and cultural conditions comprised in a thoughtstyle, they are dependent on thoughtstyles. Yet, this does not make them mere artefacts of instrumentation. Scientific practices in the laboratories define, rather, the conditions under which nature can present herself. German Die moderne Naturwissenschaft stützt sich auf empirische Daten, die weitgehend in hochkomplizierten technischen Apparaturen und Anlagen gewonnen werden. Von den Formen der alten Naturforschung ist diese Laborforschung so weit entfernt, daß sie den Vorwurf auf sich zog, sie untersuche Artefakte, aber nicht Natur. - Dagegen wird hier argumentiert, daß die Laborforschung als genuine Erbin der mit Galilei begonnenen Form der Naturwissenschaft anzuerkennen sei. Erkenntnis von den Wirkungsweisen der Natur ist nur durch gezieltes Eingreifen in Vorgänge der Natur zu gewinnen. Unter dem ,,Laboratorium haben wir allerdings weniger den Ort des Experimentierens zu verstehen, als vielmehr den in einer Arbeitsgruppe praktizierten ,,Denkstil, in dem die Formen des Forschungshandelns mit den (sozialen) Strukturen der arbeitsteiligen Kooperation verbunden sind. - Wissenschaftliche Tatsachen lassen sich zwar nicht von den Bindungen an einen Denkstil ablösen, sie erweisen sich als denkstilabhängig; das macht sie aber nicht zu Kunstprodukten. Die in einem Labor praktizierten Arbeitsweisen definieren vielmehr die Bedingungen, unter denen Natur sich zeigen kann. (shrink)

Modern empiricism is usually thought to have emerged in opposition to the then dominant school of neo-Kantianism. True as this may be, it has blinded us to the fact that Kantian and more surprisingly even neo-Kantian elements of philosophy have also had a positive influence upon the development of the new empiricism. One episode in which this influence proves itself in fact dominant and which I will present in the following concerns the philosophical position which Popper adopted vis-à-vis logical empiricism (...) — as advocated by Wittgenstein and Schlick — in Vienna in the late twenties and early thirties of the last century. (shrink)

Pessoa et al. provide a valuable taxonomy of perceptual completion phenomena, but it is not yet clear whether these phenomena are mediated by one kind of neural mechanism or more. We suggest three possible neural mechanisms of long-range interaction to stimulate further perceptual and neurophysiological investigation of perceptual completion and filling-in.

Alongside the 'critical theory' of the Frankfurt School, West Germany was also home to another influential Marxist current known as the Marburg School. In this volume, Marburg disciple Lothar Peter traces the school's history and situates it in the political discourse and developments of its time. The renowned political scientist Wolfgang Abendroth plays a large role, but unlike most histories of the Marburg School Peter also takes the sociologists Werner Hofmann and Heinz Maus into account as well as their (...) many students and successors. They were united by the conviction that teaching and scholarship must necessarily be tied to the practical goal of transforming society - an approach that met with considerable opposition in the harshly anti-Communist atmosphere of the period. (shrink)

Die digitale Transformation erfasst die Medien der Literatur und Literaturkritik in unterschiedlicher Geschwindigkeit. Die Substituierung der gedruckten Zeitung, der Stammheimat der Literaturkritik, durch digitale Formate ist weit vorangeschritten. Auf dem Buchmarkt ist das gedruckte Hardcover nach wie vor ein relativ stabiles Element. Der Beitrag kommentiert diese Differenz in medienhistorischer Perspektive.

The choliambic metre of the prologue poem of Persius’ Satires is key to understanding the poem’s message. On the one hand it creates a link to Hipponax as the canonical exponent of the iambic genre and to the tale of his inspiration transmitted by Giorgios Choiroboskos, and so attests the presence of the iambic poet in the cultured literary circles at Nero’s imperial court. On the other hand the poet alludes to Callimachus, his iambic poetry and his poetology, and so (...) adopts his rejection of a poetry that has sunk to mere literary convention. This casts new light both on Persius’ own claim to be a semipaganus and on his mockery of the profit-oriented corvi and picae. (shrink)

This classic work in vision science, written by a leading figure in Germany's Gestalt movement in psychology and first published in 1936, addresses topics that remain of major interest to vision researchers today. Wolfgang Metzger's main argument, drawn from Gestalt theory, is that the objects we perceive in visual experience are not the objects themselves but perceptual effigies of those objects constructed by our brain according to natural rules. Gestalt concepts are currently being increasingly integrated into mainstream neuroscience by researchers (...) proposing network processing beyond the classical receptive field. Metzger's discussion of such topics as ambiguous figures, hidden forms, camouflage, shadows and depth, and three-dimensional representations in paintings will interest anyone working in the field of vision and perception, including psychologists, biologists, neurophysiologists, and researchers in computational vision--and artists, designers, and philosophers.Each chapter is accompanied by compelling visual demonstrations of the phenomena described; the book includes 194 illustrations, drawn from visual science, art, and everyday experience, that invite readers to verify Metzger's observations for themselves. Today's researchers may find themselves pondering the intriguing question of what effect Metzger's theories might have had on vision research if Laws of Seeing and its treasure trove of perceptual observations had been available to the English-speaking world at the time of its writing. (shrink)

There are few articles in science that remain relevant over a span of 100 years; Max Wertheimer's pioneering experimental studies on apparent motion and figural organization are notable exceptions. Wertheimer's 1912 account of motion perception started a revolution and established the Gestalt school of psychology. It also paved the way for further investigations of apparent motion perception, including subsequent research by Oliver Braddick, Stuart Anstis, Vilaynur Ramachandran, and others. Wertheimer's 1923 article on figural organization helped define grouping as a principle (...) of figure-ground perception. This book provides contemporary readers and researchers with Wertheimer's two pivotal articles, newly translated into English and each accompanied by a synopsis, and two essays on apparent motion and figural organization that describe the long-term impact of Wertheimer's work. The translation of the original German into readable English prose allows English-language readers for the first time to appreciate Wertheimer's visionary ideas. The accompanying essays tie Wertheimer's phenomenological descriptions to the underlying neuronal mechanisms, bridging the years between the articles' first publication and modern research. (shrink)