Despite the prominence of thresholds in theories of distributive justice, there is no general account of what sort of role is played by the idea of a threshold within such theories. This has allowed an ongoing lack of clarity and misunderstanding around views that employ thresholds. In this article, I develop an account of the concept of thresholds in distributive justice. I argue that this concept contains three elements, which threshold views deploy when ranking possible distributions. These elements (...) are (i) the level of the threshold, (ii) what constitutes the value of the threshold, and (iii) how benefits above and below the threshold must be allocated. I highlight three contributions that this particular account of thresholds makes: it clarifies the nature of the shift that occurs at the threshold; it resolves a common misunderstanding about headcount principles; and it shows how the arbitrariness objection can be met. (shrink)

Application of egalitarian and prioritarian accounts of health resource allocation in low‐income countries have both been criticized for implying distribution outcomes that allow decreasing/undermining health gains and for tolerating unacceptable standards of health care and health status that result from such allocation schemes. Insufficient health care and severe deprivation of health resources are difficult to accept even when justified by aggregative efficiency or legitimized by fair deliberative process in pursuing equality and priority oriented outcomes. I affirm the sufficientarian argument that, (...) given extreme scarcity of public health resources in low‐income countries, neither health status equality between populations nor priority for the worse off is normatively adequate. Nevertheless, the threshold norm alone need not be the sole consideration when a country's total health budget is extremely scarce. Threshold considerations are necessary in developing a theory of fair distribution of health resources that is sensitive to the lexically prior norm of sufficiency. Based on the intuition that shares must not be taken away from those who barely achieve a minimal level of health, I argue that assessments based on standards of minimal physical/mental health must be developed to evaluate the sufficiency of the total resources of health systems in low‐income countries prior to pursuing equality, priority, and efficiency based resource allocation. I also begin to examine how threshold sensitive health resource assessment could be used in the Philippines. (shrink)

The threshold problem is the task of adequately answering the question: “Where does the threshold lie between knowledge and lack thereof?” I start this paper by articulating two conditions for solving it. The first is that the threshold be neither too high nor too low; the second is that the threshold accommodate the significance of knowledge. In addition to explaining these conditions, I also argue that it is plausible that they can be met. Next, I argue (...) that many popular accounts of knowledge cannot meet them. In particular, I lay out a number of problems that standard accounts of knowledge face in trying to meet these conditions. Finally, near the end of this paper, I argue that there is one sort of account that seems to evade these problems. This sort of account, which is called a cluster account of knowledge, says that knowledge is to be accounted for in terms of truth, belief and a cluster of epistemic properties and also that knowledge doesn’t require having all members of the cluster, but merely some subset. (shrink)

The Threshold of the Visible World advances a revolutionary new political aesthetic--Kaja Silverman explores the possibilities for looking beyond the restrictive mandates of the self, and the normative aspects of the cultural image-repertoire. She provides a detailed account of the social and psychic forces which constrain us to look and identify in normative ways, and the violence which that normativity implies. Accounting for these phenomena on both a conscious and an unconcious level, Silverman analyzes the psychic and textual conditions (...) under which our "field of vision" can be expanded. The title of this book is taken from Lacan's essay on the mirror stage. In that text, Lacan writes that "the mirror-image would seem to be the threshold of the visible world." He thereby suggests that the visible world has no existence as such until the infant subject has access to an image of self. Lacan intimates that the mirror provides the frame through which one relates to others within the domain of vision, stressing the priority of narcissism and the ego over all other libidinal transactions. The Threshold of the Visible World provides a psychic, social and political specification of Lacan's claim, and most particularly of its implications for the subject's relations to the social other. This is accomplished through examination of the ego, as well as two other categories at the center of Lacan's account of the mirror stage: ideality and identification. This book is an ethical-political project which leads to the re-elaboration of a number of crucial theoretical categories--Silverman offers an account of the bodily ego, of identification, of idealization, of the gaze, of the look, and of the "photographic." The Threshold of the Visible World leads as well to the formulation of a fresh model for conceptualizing sexual, racial and class "difference," and the terms under which it might be dismantled. This book thus seeks to apprehend the field of vision through the frame of a different kind of bodily ego, and discover the pleasures to be derived from corporeal transport. (shrink)

Haptic-based vibrotactile biofeedback (BF) is a promising technique to improve rehabilitation of balance in stroke patients. However, the extent to which BF training changes temporal structure of the center of pressure (CoP) trajectories remains unknown. This study aimed to investigate the effect of vibrotactile BF training on the temporal structure of CoP during quiet stance in chronic stroke patients using detrended fluctuation analysis (DFA). Nine chronic stroke patients (age; 81.56±44 months post-stroke) received a balance training regimen using a (...) vibrotactile BF system twice a week over four weeks. A Wii Balance board was used to record five 30 s trials of quiet stance pre- and post-training at 50 Hz. DFA revealed presence of two linear scaling regions in CoP indicating presence of fast- and slow-scale fluctuations. Averaged across all trials, fast-scale fluctuations showed persistent dynamics ( = 1.05 ±.08 for ML and  = 0.99 ±.17 for AP) and slow-scale fluctuations were anti-persistent ( = 0.35 ±.05 for ML and  = 0.32 ±.05 for AP). The slow-scale dynamics of ML CoP in stroke patients decreased from pre-training to post-BF training ( = 0.40 ±.13 vs. 0.31 ±.09). These results suggest that the vibrotactile BF training affects postural control strategy used by chronic stroke patients in the ML direction. Results of the DFA are further discussed in the context of balance training using vibrotactile BF and interpreted from the perspective of intermittent control of upright stance. (shrink)

Despite the prominence of thresholds and limits in theories of distributive justice, there is no general account of their role within such theories. This has allowed an ongoing lack of clarity and misunderstanding around threshold views in distributive justice. In this thesis, I develop an account of the conceptual structure of such views. Such an account helps understand and characterize threshold views, can subsume what may seem to be different debates about such views under one conceptual header, and (...) can be used to further examine and develop patterns of justice that draw on thresholds. In light of this account, I propose a novel characterization of sufficientarianism which sheds new light on the distinctiveness of sufficientarianism as a distributive principle and on the common objections to sufficientarianism. Moreover, I examine and defend limitarianism, which is the view that people should not have more than a certain amount of wealth. In particular, I argue in favour of limitarianism as a midlevel principle for guiding institutional design and individual actions and, furthermore, as a specification of what a just allocation of wealth requires under epistemic constraints. (shrink)

If you believe that there are restrictions on what we as moral agents can do to others, but that these restrictions can give way in the face of competing considerations, then you believe in thresholds for rights. In this dissertation I develop an account of thresholds for rights, in defence of a position which is often stated but rarely explained or defended. I begin with the obvious question: How much needs to be at stake before a right's claim is overridden? (...) ;Less obvious, but equally crucial, are questions about the distribution of the total which needs to be at stake. After developing a framework for answering that question, in subsequent chapters I deal with other factors which may influence our judgements about the overridability of rights' claims, including the numbers and identities of the agents involved. (shrink)

In sensory biology, a major outstanding question is how sensory receptor cells minimize noise while maximizing signal to set the detection threshold. This optimization could be problematic because the origin of both the signals and the limiting noise in most sensory systems is believed to lie in stimulus transduction. Signal processing in receptor cells can improve the signal‐to‐noise ratio. However, neural circuits can further optimize the detection threshold by pooling signals from sensory receptor cells and processing them using (...) a combination of linear and nonlinear filtering mechanisms. In the visual system, noise limiting light detection has been assumed to arise from stimulus transduction in rod photoreceptors. In this context, the evolutionary optimization of the signal‐to‐noise ratio in the retina has proven critical in allowing visual sensitivity to approach the limits set by the quantal nature of light. Here, we discuss how noise in the mammalian retina is mitigated to allow for highly sensitive night vision. (shrink)

Categorical perception (CP) is said to occur when a continuum of equally spaced physical changes is perceived as unequally spaced as a function of category membership (Harnad, S. (Ed.) (1987). Psychophysical and cognitive aspects of categorical perception: A critical overview. Cambridge: Cambridge University Press). A common suggestion is that CP for color arises because perception is qualitatively distorted when we learn to categorize a dimension. Contrary to this view, we here report that English speakers show no evidence of lowered discrimination (...) thresholds at the boundaries between blue and green categories even though CP is found at these boundaries in a supra-threshold task. Furthermore, there is no evidence of different discrimination thresholds between individuals from two language groups (English and Korean) who use different color terminology in the blue-green region and have different supra-threshold boundaries. Our participants' just noticeable difference (JND) thresholds suggest that they retain a smooth continuum of perceptual space that is not warped by stretching at category boundaries or by within-category compression. At least for the domain of color, categorical perception appears to be a categorical, but not a perceptual phenomenon. (shrink)

How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation trade‐offs using a novel card selection task that captures the common situation of searching among multiple resources (e.g., jobs) that can be exploited without depleting. With experience, participants learn to switch appropriately between exploration and exploitation and approach optimal performance. We model participants' behavior on this task with random, threshold, and sampling strategies, and find (...) that a linear decreasing threshold rule best fits participants' results. Further evidence that participants use decreasing threshold‐based strategies comes from reaction time differences between exploration and exploitation; however, participants themselves report non‐decreasing thresholds. Decreasing threshold strategies that “front‐load” exploration and switch quickly to exploitation are particularly effective in resource accumulation tasks, in contrast to optimal stopping problems like the Secretary Problem requiring longer exploration. (shrink)

Mental-threshold egalitarianism, well-known examples of which include Jeff McMahan’s two-tiered account of the wrongness of killing and Tom Regan’s theory of animal rights, divides morally considerable beings into equals and unequals on the basis of their individual mental capacities. In this paper, I argue that the line that separates equals from unequals is unavoidably arbitrary and implausibly associates an insignificant difference in empirical reality with a momentous difference in moral status. In response to these objections, McMahan has proposed the (...) introduction of an intermediate moral status. I argue that this move ultimately fails to address the problem. I conclude that, if we are not prepared to give up moral equality, our full and equal moral status must be grounded in a binary property that is not a threshold property. I tentatively suggest that the capacity for phenomenal consciousness is such a property, and a plausible candidate. (shrink)

A small consortium of philosophers has begun work on the implications of epistemic networks (Zollman 2008 and forthcoming; Grim 2006, 2007; Weisberg and Muldoon forthcoming), building on theoretical work in economics, computer science, and engineering (Bala and Goyal 1998, Kleinberg 2001; Amaral et. al., 2004) and on some experimental work in social psychology (Mason, Jones, and Goldstone, 2008). This paper outlines core philosophical results and extends those results to the specific question of thresholds. Epistemic maximization of certain types does show (...) clear threshold effects. Intriguingly, however, those effects appear to be importantly independent from more familiar threshold effects in networks. (shrink)

The continuity thesis of the Poznań school threshold model of the growth of scientific knowledge is considered in the light of the example of Van der Waals' and Boyle-Mariotte's laws. It is argued - using both traditional logical means and the structuralist reconstruction of the example - that the continuity thesis does not hold. A distinction between 'a historical and a systematic point of view' is introduced and it is argued that the continuity thesis of the threshold model (...) presupposes the systematic point of view. However, looking at matters from the systematic point of view need not yield the original theory, looked at from the historical point of view. Applied to the case of Van der Waals/Boyle-Mariotte laws, it turns out that the latter law is not a true idealizing special case of the former, contrary to the continuity thesis. The structuralist analysis of the example indicates that Boyle-Mariotte's law is a false factual law from the historical point of view. However, viewed from the systematic point of view, Boyle-Mariotte's law turns out to be a law which is expandable, adding the relevant new concepts, to an idealized version of Van der Waals' law. This idealizing version of Van der Waal's law in turn is a structuralist specialization of the (general) Van der Waals' law. (shrink)

The threshold law for N-body fragmentation under dipole forces is formulated. It emerges from the energy dependence of the normalization of the correlated continuum wave function for N fragments. It is shown that the dipole threshold law plays a key role in understanding all threshold fragmentation phenomena since it links the classical threshold law for long-range Coulomb interactions to the statistical law for short-range interactions. Furthermore, a tunnelling mechanism is identified as the common feature which occurs (...) for all three classes of interactions, short-range, dipole and Coulomb. (shrink)

_Threshold Concepts in Problem-based Learning_ provides a critical discussion and guidance for educational researchers, teachers, innovators and policy makers wanting to explore the interrelationship of PBL and threshold concepts.

It has been argued that the precautionary principle is incoherent and thus useless as a guide for regulatory policy. In a recent paper in Bioethics, Wareham and Nardini propose a response to the ‘precautionary paradox’ according to which the precautionary principle's usefulness for decision making in policy and regulation contexts can be justified by appeal to a probability threshold discriminating between negligible and non‐negligible risks. It would be of great significance to debates about risk and precaution if there were (...) a sound method for determining a minimum probability threshold of negligible risk. This is what Wareham and Nardini aim to do. The novelty of their approach is that they suggest that such a threshold should be determined by a method of public deliberation. In this article I discuss the merits of Wareham and Nardini’s public deliberation method for determining thresholds. I raise an epistemic worry about the public deliberation method they suggest, and argue that their proposal is inadequate due to a hidden assumption that the acceptability of a risk can be completely analysed in terms of its probability. (shrink)

In this paper we study changes of beliefs in a ranking-theoretic setting using non-extremal implausibility thresholds for belief. We represent implausibilities as ranks and introduce natural rank changes subject to a minimal change criterion. We show that many of the traditional AGM postulates for revision and contraction are preserved, except for the postulate of Preservation which is invalid. The diagnosis for belief contraction is similar, but not exactly the same. We demonstrate that the one-shot versions of both revision and contraction (...) can be represented as revisions based on semiorders, but in two subtly different ways. We provide sets of postulates that are sound and complete in the sense that they allow us to prove representation theorems. We show that, and explain why, the classical duality between revision and contraction, as exhibited by the Levi and Harper identities, is partly broken by threshold-based belief changes. We also study the logic of iterated threshold-based revision and contraction. The traditional Darwiche-Pearl postulates for iterated revision continue to hold, as well as two additional postulates that characterize ranking-based revision as a restricted `improvement' operator. We investigate the dual notion of iterated threshold-based belief contraction and provide a new set of postulates for it, characterizing contraction as a restricted 'degrading' operator. (shrink)

When should doctors seek protective custody to override a parent’s refusal of potentially lifesaving treatment for their child? The answer to this question seemingly has different answers for different subspecialties of pediatrics. This paper specifically looks at different thresholds for physicians overriding parental refusals of life-sustaining treatment between neonatology, cardiology, and oncology. The threshold for mandating treatment of premature babies seems to be a survival rate of 25–50%. This is not the case when the treatment in question is open (...) heart surgery for a child with congenital heart disease. Most cardiologists would not pursue legal action when parents refuse treatment, unless the anticipated survival rate after surgery is above 90%. In pediatric oncology, there are case reports of physicians requesting and obtaining protective custody for cancer treatment when the reported mortality rates are 40–50%. Such differences might be attributed to differences in care, a reasonable prioritization of quality of life over survival, or the role uncertainty plays on prognoses, especially for the extremely young. Nonetheless, other, non-medical factors may have a significant effect on inconsistencies in care across these pediatric subspecialties and require further examinations. (shrink)

John McCumber; The Threshold of Bio-Ethics: Philosophical Warrant in the Thought of Stephen Erickson, Christian bioethics: Non-Ecumenical Studies in Medical Mor.

The threshold view says that a person forms an outright belief P if and only if her credence for P reaches a certain threshold. Using computer simulations, I compare different versions of the threshold view to understand how they perform under time pressure in decision problems. The results illuminate the strengths and weaknesses of the various cognitive strategies in different decision contexts. A threshold view that performs well across diverse contexts is likely to be a cognitively (...) flexible and context-dependent fusion of several of the existing theories. The results of the simulations also cast doubts on the possibility of a threshold view that is both simple enough to streamline our reasoning while also allowing us to form good action-guiding beliefs. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 33.4 (2000) 303-318 [Access article in PDF] The Threshold of the Self Bradford Vivian The subject has a history. Classical Greek sculpture expressed a fascination with the formal beauty of one's self. Ever gazing outward or upward, the marble figures symbolized the Greek preoccupation with a boldness of being, a constant focus on the ideals of the body and mind, which, through their pursuit, might (...) allow one a foretaste of heaven. Centuries later, as the pagan symbols of the ancient world were replaced with those of the growing Byzantine Empire, blocks of the same marble were fashioned into very different expressions. The ideals of form made manifest in the smooth, taught lines and surfaces of classical Greek sculpture were supplanted by Byzantine art's attention to the less perfect details of the individual: distinctive and common faces, beards, clothing, and less glorified bodies. The gazes of the Byzantine statues were cast down, contemplative, reflecting Byzantium's early Christian emphasis upon the modesty of human existence, the pious appraisal of one's time on Earth. Each of these sculptural styles is a material way of thinking and expressing one's being in the world. In this context, each is also symptomatic of the conditions in which such being was possible.The subject must not be conceived as a transcendent entity. Quite to the contrary, there is a historicity to our being and its expression, to our subjectivity and its elaboration. Within a more sweeping perspective, our epochal narratives of the subject--as well as the modes of thought and speech by which we make sense of ourselves--change with each passing age.At the forefront of the current era is a manifold effort to rethink and elaborate anew the concept of the subject. Feminist scholars have initiated political critique and transformation by arguing that the very notion of a subject in Western discourse has functioned as a trope of masculine privilege cloaked in the language of equality and secular humanism. 1 Postmodernists, of course, define contemporary subjectivity as de-centered and fragmented by nature (e.g., Baudrillard 1994; Latour 1993; Lyotard 1984). And [End Page 303] a variety of interdisciplinary studies illuminate the role of modern science and technology in not only sustaining our being, but actually constituting the human; in short, our daily interdependence and union with artificial body parts, synthetic products, life-support machines, test-tube reproduction, computers, and more, characterizes the arrival of what has been called "the posthuman." 2 Like ancient marble from a quarry, however, all of these materials are sculpted in historically specific ways to simultaneously think and express our subjectivity.What role might rhetoric play in this re-imagining of subjectivity? Modern Western thought has defined the subject according to content--that is, by the nature of the essence or being the subject is said to possess. Drawn around this content, the subject comes to appear enclosed, perhaps autonomous, and identical to itself. In this essay, however, I argue that the self may be conceived as a form--a rhetorical form--that exists only in its continual aesthetic creation, in its indefinite becoming. The self is, by this account, isomorphic with the threshold out of which it is composed. Such a formulation makes the self open to difference, to continual movement and transformation, instead of identical to itself.I aim in this essay to explore the abstract rhetorical forms and functions out of which the self is composed. The distinction here amounts to no longer asking, "What is a subject?" but, "What conditions and forces enable the ongoing production of the self?" Commensurate with such a proposal, it will be essential to ask how this movement--this continual becoming--of the self is brought about. The answer to this question ultimately will amplify the role of rhetoric in, not simply expressing, but actually producing conditions of being. In what follows, I begin by reviewing the very general aspects of subjectivity that I wish to call into question. Thereafter, I explore how the subject might be conceived differently. Finally, I discuss the manner in which rhetoric may... (shrink)

A dynamic threshold, which controls the nature and course of learning, is a pivotal concept in Page's general localist framework. This commentary addresses various issues surrounding biologically plausible implementations for such thresholds. Relevant previous research is noted and the particular difficulties relating to the creation of so-called instance representations are highlighted. It is stressed that these issues also apply to distributed models.

_Threshold Concepts on the Edge_ explores new directions in threshold concept research and practice and is of relevance to teachers, learners, educational researchers and academic developers.