Detection of three-dimensional surfaces from optic flow: The effects of noise

Previous research (Andersen, 1989) has suggested that the recovery of 3-D shape from nonsmooth optic flow (motion transparency) can be performed by segregating surfaces according to the distributions of velocities present in the flow field. Five experiments were conducted to examine this hypothesis in a surface detection paradigm and to determine the limitations of human observers to detect 3-D surfaces in the presence of noise. Two display types were examined: a flow field that simulateda surface corrugated in depth and a flow field-that simulated a random volume. In addition, two types of noise were examined: a distribution of noise velocities that overlapped or did not overlap the velocity distribution that defined the -surface. Corrugation frequency and surface density were also examined. Detection performance increased with decreasing corrugation frequency, decreasing noise density, and decreasing surface density. Overall, the subjects demonstrated remarkable tolerance to the presence of noise and, for some conditions, could discriminate surface from random conditions when noise density was twice the-surface density. Discrimination accuracy was greater for the nonoverlapping than for the overlapping noise, providing support for an analysis based on the distribution of velocities.     

Interaction between theory and practice in the surgical treatment of ulcer disease in the period of 1880–1920

Newly developed techniques for anaesthesia and asepsis made it possible for surgeons to attempt operative attacks on diseases which had been previously incurable. The period around the turn of the century is sometimes portrayed as one of very active development of new surgical methods. This activity has been seen as a result of fertile scientific thinking. It is demonstrated in the paper that it was in fact a barren period with a prolonged adherence to an anatomical concept as the basis for problem solving. It is described in terms of Kuhnian periods of normal activity and crisis. It took about fifty years before theory and practice were harmonized under a physiological concept and real progress was made.     

Examining psychokinesis: the interaction of human intention with random number generators--a meta-analysis

Séance-room and other large-scale psychokinetic phenomena have fascinated humankind for decades. Experimental research has reduced these phenomena to attempts to influence (a) the fall of dice and, later, (b) the output of random number generators (RNGs). The meta-analysis combined 380 studies that assessed whether RNG output correlated with human intention and found a significant but very small overall effect size. The study effect sizes were strongly and inversely related to sample size and were extremely heterogeneous. A Monte Carlo simulation revealed that the small effect size, the relation between sample size and effect size, and the extreme effect size heterogeneity found could in principle be a result of publication bias.     

Perceived internal depth in rotating and translating objects

Previous research has indicated that observers use differences between velocities and ratios of velocities to judge the depth within a moving object, although depth cannot in general be determined from these quantities. In four experiments we examined the relative effects of velocity difference and velocity ratio on judged depth within a transparent object that was rotating about a vertical axis and translating horizontally, examined the effects of the velocity difference for pure rotations and pure translations, and examined the effect of the velocity difference for objects that varied in simulated internal depth. Both the velocity difference and the velocity ratio affected judged depth, with difference having the larger effect. The effect of velocity difference was greater for pure rotations than for pure translations. Simulated depth did not affect judged depth unless there was a corresponding change in the projected width of the object. Observers appear to use the velocity difference, the velocity ratio, and the projected width of the object heuristically to judge internal object depth, rather than using image information from which relative depth could potentially be recovered.     

Theological Ethics, Moral Philosophy, and Natural Law

The article deals with the relationship between theological ethics and moral philosophy. The former is seen as a theoretical reflection on Christian ethics, the latter as one on secular ethics. The main questions asked are: (1) Is there one and only one pre-theoretical knowledge about acting rightly? (2) Does philosophy provide us with the theoretical framework for understanding both Christian and secular ethics? Both questions are answered in the negative. In the course of argument, four positions are presented: theological ‘unificationism’, philosophical ‘unificationism’, theological ‘separationism’ and Lutheran ‘dualism’. It is argued that the latter position is most convincing. It is dual in the sense of being both a theory of Christian ethics and of including a recognition of natural law. Hence, it unites a particularistic and a universalistic point of view. In the last section a reformulation of the Lutheran position is attempted in making use of the ethical theory of Knud E. Løgstrup's The Ethical Demand.     

Relational to collective: significant-other representations, ethnic categories, and intergroup perceptions

Social perception is known to be affected by the social-cognitive process of transference-that is, by a new person bearing a minimal resemblance to a significant other, which activates the significant-other representation and indirectly the relational self. We examined relational processes in social identity and intergroup bias in two studies testing the dual hypothesis-that activating a significant-other representation in transference activates the significant other's ethnic category, which is then applied to the new person, and that under this circumstance the participant's own ethnic identity should also be activated as the relational self is activated, particularly if the participant shares the significant other's ethnicity. This should lead to shifts in intergroup bias as moderated by the ethnic diversity of the significant other's own social network. The evidence largely supports this, revealing the interplay of relational and collective levels of self.     

Anxiety and cancer treatment: response to stressful radiotherapy

Previous research with individuals undergoing surgery or diagnostic procedures provided a conceptual framework for analysis of radiation therapy, a common form of cancer treatment. The present investigation was designed to document the magnitude of anxiety patients experience in response to one particularly stressful form of radiation treatment. In addition, the change in anxiety responses with repeated exposures and individual differences among patients that may affect their adjustment were explored. In Part 1, gynecologic cancer patients receiving their first internal radiotherapy application were studied. As the time for treatment neared, subjective and physiologic indicants of anxiety and distress among the patients significantly increased. By 24 hours post-treatment, anxiety for all patients remained elevated. These post-treatment data are convergent with other investigations of post-treatment distress among cancer patients, but contrast with data obtained from those receiving treatment for benign conditions. A subset of the women who required two applications of radiotherapy participated in Part 2. These patients continued to respond negatively during the second treatment. Data on individual differences in anxiety responses (i.e., low vs. high anxiety) were obtained in both investigations and suggest that those with low levels of pre-treatment anxiety experience considerable disruption post-treatment.     

What Does Society Owe Me If I Am Responsible for Being Worse Off?

Luck egalitarians need to address the question of cost‐responsibility: If an individual is responsible for being worse off than others, then what benefits, if any, is that individual uniquely cost‐responsible for? By applying luck egalitarianism to justice in health I discuss different answers to this question inspired by two different interpretations of luck egalitarianism, namely ‘standard luck egalitarianism’ and ‘all luck egalitarianism’, respectively. Even though I argue that the latter is more plausible than the former, I ultimately suggest and defend a third interpretation of luck egalitarianism, which I label ‘universal luck egalitarianism’. Finally, I adjust my findings to a (all things considered) more plausible currency, namely welfare.     

Epistemic expressivism and the argument from motivation

This paper explores in detail an argument for epistemic expressivism, what we call the Argument from Motivation. While the Argument from Motivation has sometimes been anticipated, it has never been set out in detail. The argument has three premises, roughly, that certain judgments expressed in attributions of knowledge are intrinsically motivating in a distinct way (P1); that motivation for action requires desire-like states or conative attitudes (HTM); and that the semantic content of knowledge attributions cannot be specified without reference to the intrinsically motivating judgments that such attributions express (P2). We argue that these premises entail a version of ecumenical expressivism. Since the argument from motivation has not been explicitly stated before, there is no current discussion of the argument. In this paper we therefore consider and reject various objections that one might propose to the argument, including some that stem from the idea that knowledge is factive, or that knowledge involves evidence that rules out relevant alternatives. Other objections to (P1) specifically might be derived from cases of apparent lack of epistemic motivation considered in in Kvanvig (The value of knowledge and the pursuit of understanding, 2003) and Brown (Nous 42(2):167–189, 2008), as well as from general forms of externalism about epistemic motivation. We consider these and find them wanting. Finally, the paper offers some critical remarks about the prospect of denying (P2).     

Metaphysics Within Science: Against Radical Naturalism

In Every Thing Must Go James Ladyman and Don Ross argue for a radical version of naturalistic metaphysics and propose that contemporary analytic metaphysics is detached from science and should be discontinued. The present article addresses the issues of whether (i) science and metaphysics are separable, (ii) intuitions and understanding should be excluded from scientific theory, and (iii) Ontic Structural Realism satisfies the criteria of the radical version of naturalism advanced by Ladyman and Ross. The point underlying those topics is that successful scientific research presupposes metaphysics, and that basic epistemic virtues common to metaphysics and science may allow us—as opposed to what Ladyman and Ross suggest—to increase our understanding of the world and to put constraints on allowable metaphysical theories.