The Temporal-Order Judgment (TOJ) paradigm has been widely investigated in previous studies as an accurate measure of temporal resolution and sequencing abilities in the millisecond time range. Two auditory TOJ tasks are often used: (1) a spatial TOJ task, in which two identical stimuli are presented in rapid succession monaurally and the task is to indicate which ear received the first stimulus and which ear received the second one ( left-right or right-left ), and (2) a spectral TOJ task, in (...) which two tones of different frequencies are presented asynchronously to both ears binaurally and the task is to report the sequence of these tones ( low-high or high-low ). The previous literature studies conducted on young volunteers indicated that the measured temporal acuity on these two tasks depended on the procedure used. As considerable data are now available about age-related decline in temporal resolution ability, the aim of the present study was to compare in elderly subjects the pattern of performance on these two tasks. A total of 40 normal healthy volunteers aged from 62 to 78 years performed two TOJ tasks. The measurement was repeated in two consecutive sessions. Temporal resolution was indexed by the Auditory Temporal-Order Threshold (ATOT), i.e., the minimum time gap between successive stimuli necessary for a participant to report a before-after relation with 75% correctness. The main finding of the present study was the indication of differences in the elderly in performance on two tasks. In the spatial task, the distribution of obtained ATOT values did not deviate from the Gaussian distribution. In contrast, the distribution of data in the spectral task deviated significantly from the Gaussian and was spread more to the right. Although lower ATOT values were usually observed in Session 2 than in Session 1, such difference was significant only in the spectral task. We conclude that although temporal acuity and sequencing abilities in the millisecond time range are probably based in neuronal oscillatory activity, the measured ATOTs in the elderly seem to be stimulus-dependent, procedure-related, and influenced by the perceptual strategies used by participants. (shrink)

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)

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)

_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.

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)

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

This essay represents a serious but fictional obituary of a scientific concept called the Threshold Dose–Response Model, which has long dominated the fields of toxicology and the broader biomedical sciences. Recent evidence indicates that the Threshold Dose–Response Model has long outlived its utility to predict low‐dose effects. In fact, so poorly does this model predict low‐dose responses that the idea arose that it should receive a symbolic burial recounting its achievements and failings, hence this obituary. BioEssays 29:686–688, 2007. © 2007 (...) Wiley Periodicals, Inc. (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)

Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition) or flexibility (by dampening competition and biasing). We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style toward flexibility, which in turn should increase the crosstalk (...) between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task—an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style toward more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias. (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)

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)

While genomic and proteomic information describe the overall cellular machinery available to an organism, the metabolic profile of an individual at a given time provides a canvas as to the current physiological state. Concentration levels of relevant metabolites vary under different conditions, in particular, in the presence or absence of different disorders. Metabolite concentrations thus mediate an important link between chemistry and biology, contributing to a systems-wide understanding of biological processes and pathways. However, there are a number of challenges in (...) the ontological representation of such information. Firstly, concentration information is numeric and ranges over continuous values, while ontologies consist of discrete classes. Secondly, ontologies usually model only what is certain, and their logical formalisms are adapted to reasoning from certain axioms to logical deductions, however, the link between chemicals and diseases via concentration levels, like many threshold phenomena, is both uncertain and vague. In this paper we evaluate the representation of this knowledge using a combination of concrete domains and probabilistic reasoning. We parse concentration values from HMDB and create an ontology able to distinguish normal from abnormal concentrations and able to evaluate a probabilistic risk category for the presence of an associated disorder. (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)

Touching on Nancy and Derrida offers a glimpse not only into the thesis both of Jean-Luc Nancy's critique of touch and of Derrida's Le Toucher, but also into the threshold of a technology of (the) sense to come. This glimpse is an interrogation, and one that is both historic and historical, in the sense that Derrida, in addressing Jean-Luc Nancy's work, has presented us with an encyclopedic history of touch in the philosophic tradition from Aristotle to Nancy, one in which (...) what Derrida calls “transcendental archifacticity” is accorded its proper value, and within which any seeming anthropological privilege, as an inherent aspect of the Phenomenological Reduction is, as Derrida says, ‘overshadowed.’ Such an overshadowing is both strategic, in terms of a historical phenomenological project, and tactical, in Derrida's investigative sense: tactical in terms of implementation, manifestation, manipulation (i.e. through the application of the hand, manus) and in terms of tact, tactility; to which must be tacked on, à la Nancy, con-tact, ‘with touch,’ a ‘with-touch’ in which a béance, a gash or dash, opens out in-between, ‘at the very point’ to use Derrida's repeated specification, of bifurcation and of con-tact, at the junction point of the ‘spacing out’ of a laminated différance con-noting more than it has or had ever done in Derrida's work itself. *. (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)

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)

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)

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)

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 concept of the threshold is a central one for thinking about relations between nonhuman and human animals. It refers to hosting and being hosted, the host and the guest, the inside and the outside of the domestic space. It also invokes values of mutual respect and attentiveness. This paper draws on ethological and philosophical sources to argue for the importance of the threshold in understanding human–animal interactions. Violence, sociality, technology and altruism are bound up in the threshold. As such, (...) the concept contains both descriptive and normative dimensions, encompassing both dimensions of the Greek ēthos. (shrink)

In “Constitutivism without Normative Thresholds,” Kathryn Lindeman raises two objections to what she aptly calls Threshold Constitutivism. My aim in this short discussion is to respond to her first objection. Although I will argue that this objection fails, I will also argue that thinking through how to respond to it reminds us of something important, namely, that many of the Norm-Governed Kinds that are directly related to intentional action are social kinds, that is, kinds whose existence conditions we ourselves (...) collectively write. Everyone, whether constitutivist or not, needs to think seriously about what those existence conditions should be. [1] Journal of Ethics and Social Policy 12 (3): 231-258 (2017). [2] Lindeman’s second objection depends on her view, which I do not share, that “Normative Constitutivism has ambitions to be an explanatory strategy for norms in general” (238, my emphasis). (shrink)

Most binaural speech source localization models perform poorly in unprecedentedly noisy and reverberant situations. Here, this issue is approached by modelling a multiscale dilated convolutional neural network. The time-related crosscorrelation function and energy-related interaural level differences are preprocessed in separate branches of dilated convolutional network. The multiscale dilated CNN can encode discriminative representations for CCF and ILD, respectively. After encoding, the individual interaural representations are fused to map source direction. Furthermore, in order to improve the parameter adaptation, a novel (...) semiadaptive entropy is proposed to train the network under directional constraints. Experimental results show the proposed method can adaptively locate speech sources in simulated noisy and reverberant environments. (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)

Every threshold is placed at an edge, and yet not merely an edge, for the threshold always carries with it a sense of opening up toward or closing away from. Only that place at the edge that anticipates or remembers can constitute a threshold. The threshold thus is not a place in which one can remain – to do so is for it to cease to be a threshold – but is always a place of movement and transition. Indeed, one (...) might say that the threshold is the coalescence of a time into the form of a place, since the threshold only appears as a threshold in that time of opening-toward or closing-away-from. The being of the threshold as a place is therefore essentially determined by the event of approach or withdrawal, anticipation or remembrance, arrival or departure, coming-to-be or passingaway. (shrink)