Correspondence should be addressed to David A. Leopold [email protected] the viewing of certain patterns, widely known as ambiguous or puzzle figures, perception lapses into a sequence of spontaneous alternations, switching every few seconds between two or more visual interpretations of the stimulus. Although their nature and origin remain topics of debate, these stochastic switches are generally thought to be the automatic and inevitable consequence of viewing a pattern without a unique solution. We report here that in humans such perceptual alternations (...) can be slowed, and even brought to a standstill, if the visual stimulus is periodically removed from view. We also show, with a visual illusion, that this stabilizing effect hinges on perceptual disappearance rather than on actual removal of the stimulus. These findings indicate that uninterrupted subjective perception of an ambiguous pattern is required for the initiation of the brain-state changes underlying multistable vision.Visual perception involves coordination between sensory sampling of the world and active interpretation of the sensory data. Human perception of objects and scenes is normally stable and robust, but it falters when one is presented with patterns that are inherently ambiguous or contradictory. Under such conditions, vision lapses into a chain of continually alternating percepts, whereby a viable visual interpretation dominates for a few seconds and is then replaced by a rival interpretation. This multistable vision, or 'multistability', is thought to result from destabilization of fundamental visual mechanisms, and has offered valuable insights into how sensory patterns are actively organized and interpreted in the brain1, 2. Despite a great deal of recent research and interest in multistable perception, however, its neurophysiological underpinnings remain poorly understood. Physiological studies have suggested that disambiguation of ambiguous patterns. (shrink)

The nature of motion -- Causes, forces, and resistance -- The concept of the function in fourteenth-century physics -- The significance of the theory of impetus for Scholastic natural philosophy -- Galileo and the Scholastic theory of impetus -- The theory of the elements and the problem of their participation in compounds -- The achievements of late Scholastic natural philosophy.

Understanding how activity in the brain leads to a subjective percept is of great interest to philosophers and neuroscientists alike. In the last years, neurophysiological experiments have approached this problem directly by measuring neural signals in animals as they experience well-defined visual percepts. Stimuli in these studies are often inherently ambiguous, and thus rely upon the subjective report, generally from trained monkeys, to provide a measure of perception. By correlating activity levels in the brain to this report, one can speculate (...) on the role of individual neurons and groups of neurons in the formation and maintenance of a particular percept. However, in order to draw valid conclusions from such experiments, it is critical that the responses accurately and reliably reflect what is perceived. For this reason, a number of behavioural paradigms have been developed to control and evaluate the truthfulness of responses from behaving animals. Here we describe several approaches to optimizing the reliability of a monkey's perceptual report, and argue that their combination provides an invaluable approach in the study of subjective visual perception. (shrink)

Background: Continuous viewing of ambiguous patterns is characterized by wavering perception that alternates between two or more equally valid visual solutions. However, when such patterns are viewed intermittently, either by repetitive presentation or by periodic closing of the eyes, perception can become locked or "frozen" in one configuration for several minutes at a time. One aspect of this stabilization is the possible existence of a perceptual memory that persists during periods in which the ambiguous stimulus is absent. Here, we use (...) a novel paradgim of temporally interleaved ambiguous stimuli to explore the nature of this memory, with particular regard to its potential impact on perceptual organization. Results: We found that the persistence of a perceptual configuration was robust to interposed visual patterns and, further, that at least three ambiguous patterns, when interleaved in time, could undergo parallel, stable time courses. Then, using an interleaved presentation paradigm, we established that the occasional reversal in one pattern could be coupled with that of its interleaved counterpart, and that this coupling was a function of the structural similarity between the patterns. Conclusions: We postulate that the stabilization observed with repetitive presentation of ambiguous patterns can be at least partially accounted for by processes that retain a recent perceptual interpretation, and we speculate that such memory may be important in natural vision. We further propose tha the interleaved paradigm introduced here may be of great value to gauge aspects of stimulus similarity that appeal to particular mechanisms of perceptual organization. (shrink)

In this article I try to elucidate the concept of human dignity by taking a closer look at the features of a paradigmatic torture situation. After identifying the salient aspects of torture, I discuss various accounts for the moral wrongness of such acts and argue that what makes torture a violation of human dignity is the perverted moral relationship between torturer and victim. This idea is subsequently being substantiated and defended against important objections. In the final part of the chapter (...) I give a (qualified) defense of the methodology employed in the previous sections. (shrink)

Contour adaptation is a recently described paradigm that renders otherwise salient visual stimuli temporarily perceptually invisible. Here we investigate whether this illusion can be exploited to study visual awareness. We found that CA can induce seconds of sustained invisibility following similarly long periods of uninterrupted adaptation. Furthermore, even fragmented adaptors are capable of producing CA, with the strength of CA increasing monotonically as the adaptors encompass a greater fraction of the stimulus outline. However, different types of adaptor patterns, such as (...) distinctive shapes or illusory contours, produce equivalent levels of CA suggesting that the main determinants of CA are low-level stimulus characteristics, with minimal modulation by higher-order visual processes. Taken together, our results indicate that CA has desirable properties for studying visual awareness, including the production of prolonged periods of perceptual dissociation from stimulation as well as parametric dependencies of that dissociation on a host of stimulus parameters. (shrink)

Extant literature on Political CSR and the role of governments in the governance of business conduct tends to neglect key implications of the political-institutional macro-context for public deliberation. Contextual assumptions often remain rather implicit, leading to the need for a more nuanced, explicit and context-sensitive exploration of the theoretical and practical boundary conditions of Political CSR. In non-democratic political-institutional contexts, political pluralism and participation are limited, and governmental agencies continue to play the most central role in regulation and its enforcement. (...) Drawing on a qualitative case study on a nuclear energy project in the Hashemite Kingdom of Jordan, we show how both governments and MNCs co-create a context hostile to socially responsible business conduct in the sense of Political CSR. Utilizing rich qualitative data derived from interviews, public documents, and participant observation between 2008 and 2018, we specifically illuminate how—through which interactions and strategies—the multiple governmental and corporate actors involved counter civil society demands for public deliberation, indicating the limitations of Political CSR in non-democratic political-institutional contexts. We particularly contribute to the development of Political CSR by analysing the role of coercive and discursive forms of power. We thus offer a more nuanced perspective on the role of governments in constraining the room for public deliberation in the sense of Political CSR. (shrink)

Avicenna’s theory of compounds had virtually no effect on scholastic philosophy. It is always mentioned, indeed, but only to be rejected. At most, one finds that certain thinkers take up this or that particular thought of his; or that, regarding the issue of compounds, the fundamental Averroistic or Thomistic position exhibits a certain Avicennistic tinge. This is particularly the case when it comes to Albertus Magnus, who wants to follow the thoroughly Aristotelian-Averroistic conception, while being convinced that the doctrines of (...) Averroes and Avicenna are fundamentally the same. His judgment agrees above all with that of Averroes. Since one and the same matter cannot receive many substantial forms, one cannot say that the elements in the compound are contained such that the substantial forms are wholly preserved. On the other hand, however, since the properties of the elements are found in the compound body, neither can one say that their substantial forms are in no way preserved. “And for that reason Aristotle said that the intensities of those substantial forms are reduced, and thus that in part they are preserved and in part they are changed: and so all arrive at an intermediate.”. (shrink)

Religion und Vervollkommnung – des Einzelnen wie der Kirche bzw. der Christenheit – sind eng miteinander verwoben und gründen auf der Überzeugung, den Einzelnen für das Reich Gottes vorbereiten zu müssen bzw. dieses als Kirche in der Welt zu repräsentieren. Nicht zuletzt ist die asketische Tradition des Christentums im Dienst dieses Zieles zu sehen, die durch eine methodische Lebensführung den Wandel der Seele zum Guten erreichen wollte. Gnadentheologisch war dies umstritten, weil die Möglichkeit des Menschen dazu beizutragen – je nach (...) theologischer Position – unterschiedlich gewertet wurde. Je optimistischer man hinsichtlich des menschlichen Beitrags war, umso generativer waren diese Konzepte in pädagogischer Hinsicht. Die 1909 gegründete katholische Jugendbewegung Quickborn, in der Schüler/innen höherer Schulen aktiv waren, stellt ein gutes Beispiel dafür dar, wie Religion zum Mittel sittlich-religiöser Vervollkommnung wurde. Um angesichts einer rasanten Modernisierung für gebildete junge Katholiken weiterhin relevant zu bleiben, musste an aktuellen Strömungen wie dem Abstinenzideal angeknüpft werden. Dieses war in der Reformpädagogik sowie in der Lebens- und Sozialreform um 1900 im Kaiserreich sehr präsent und konnte offenbar in Verbindung mit dem Jugendmotiv neuen religiösen Enthusiasmus wecken. Der Beitrag untersucht die Motive einer Sakralisierung der Abstinenz, ihrer pädagogischen Ziele und erwarteten Wirkungen z.B. auf Körper, Seele oder Volk sowie die verschiedenen Praktiken der Selbsterziehung und fragt schließlich danach, ob in der Verbindung von Religion und Perfektion nicht Transzendenz, konkrete Humanität (H. R. Schlette), Gnade (Kontingenz) und Fragment als doch immerhin zentrale Dimensionen biblischen Christentums ausgeblendet wurden. (shrink)

Moutoussis, K., A. Maier, S. Zeki and N. K. Logothetis: Seeing invisible motion: responses of area V5 neurons in the awake-behaving macaque. Soc. for Neurosci. Abstr. 390.11, 1.