Replies to Wang, Speaks, and Pautz

Replies for a symposium on Propositions

Précis of Propositions

Precis for symposium on Propositions

Locating Vagueness

The claim that all vagueness must be a feature of language or thought is the current orthodoxy. This is a claim about the “location” of vagueness. “Locating Vagueness” argues that this claim is false, largely by defending the possibility of borderline cases in the absence of language and thought. If the orthodoxy about the location of vagueness is false, then so too is any account of the “nature” of vagueness that implies that orthodoxy. So this paper concludes that various accounts of the nature of vagueness are false. Among such accounts, so this paper argues, are the standard versions of supervaluationism and the standard versions of epistemicism. So I conclude that those accounts are false. Along the way, I present, and uncover ways to motivate, several heretical accounts of the nature of vagueness, including nonstandard versions of both supervaluationism and epistemicism

Data-Driven Computing in Dynamics

We formulate extensions to Data Driven Computing for both distance minimizing and entropy maximizing schemes to incorporate time integration. Previous works focused on formulating both types of solvers in the presence of static equilibrium constraints. Here formulations assign data points a variable relevance depending on distance to the solution and on maximum-entropy weighting, with distance minimizing schemes discussed as a special case. The resulting schemes consist of the minimization of a suitably-defined free energy over phase space subject to compatibility and a time-discretized momentum conservation constraint. The present selected numerical tests that establish the convergence properties of both types of Data Driven solvers and solutions.Comment: arXiv admin note: substantial text overlap with arXiv:1702.0157

Economic Stressors and the Demand for "Fattening" Foods

A broad and growing literature suggests that uncertainty with respect to income, employment, and/or the financial resources necessary to buy food may cause people to gain weight. The theory—inspired by theory and evidence from behavioral ecology—posits that economic insecurity triggers a physiological fattening response, but the mechanisms by which weight gain occurs (e.g., physical activity, caloric intake, dietary quality, basal metabolism, depression) are not known. This paper reviews and synthesizes evidence supporting a dietary quality mechanism, in which economic insecurity triggers a shift in food preferences toward “fattening” foods. Interestingly, the foods to which individuals appear to be drawn under these circumstances are those which the anthropological evidence suggests would have been eaten (in pre-industrial societies) during periods of seasonal food scarcityobesity, glycemic effects, stress, evolution

Why (and When) are Preferences Convex? Threshold Effects and Uncertain Quality

It is often assumed (for analytical convenience, but also in accordance with common intuition) that consumer preferences are convex. In this paper, we consider circumstances under which such preferences are (or are not) optimal. In particular, we investigate a setting in which goods possess some hidden quality with known distribution, and the consumer chooses a bundle of goods that maximizes the probability that he receives some threshold level of this quality. We show that if the threshold is small relative to consumption levels, preferences will tend to be convex; whereas the opposite holds if the threshold is large. Our theory helps explain a broad spectrum of economic behavior (including, in particular, certain common commercial advertising strategies), suggesting that sensitivity to information about thresholds is deeply rooted in human psychology

Dopamine and the development of executive dysfunction in autism spectrum disorders.

Persons with autism regularly exhibit executive dysfunction (ED), including problems with deliberate goal-directed behavior, planning, and flexible responding in changing environments. Indeed, this array of deficits is sufficiently prominent to have prompted a theory that executive dysfunction is at the heart of these disorders. A more detailed examination of these behaviors reveals, however, that some aspects of executive function remain developmentaly appropriate. In particular, while people with autism often have difficulty with tasks requiring cognitive flexibility, their fundamental cognitive control capabilities, such as those involved in inhibiting an inappropriate but relatively automatic response, show no significant impairment on many tasks. In this article, an existing computational model of the prefrontal cortex and its role in executive control is shown to explain this dichotomous pattern of behavior by positing abnormalities in the dopamine-based modulation of frontal systems in individuals with autism. This model offers excellent qualitative and quantitative fits to performance on standard tests of cognitive control and cognitive flexibility in this clinical population. By simulating the development of the prefrontal cortex, the computational model also offers a potential explanation for an observed lack of executive dysfunction early in life

A Theory of Natural Addiction

Economic theories of rational addiction aim to describe consumer behavior in the presence of habit-forming goods. We provide a biological foundation for this body of work by formally specifying conditions under which it is optimal to form a habit. We demonstrate the empirical validity of our thesis with an in-depth review and synthesis of the biomedical literature concerning the action of opiates in the mammalian brain and their e ects on behavior. Our results lend credence to many of the unconventional behavioral assumptions employed by theories of rational addiction, including adjacent complementarity and the importance of cues, attention, and self-control in determining the behavior of addicts. Our approach suggests, however, that addiction is 'harmful' only when the addict fails to implement the optimal solution. We offer evidence for the special case of the opiates that harmful addiction is the manifestation of a mismatch between behavioral algorithms encoded in the human genome and the expanded menu of choices- -generated for example, by advances in drug delivery technology--faced by consumers in the modern world.self-control, endogenous opioids, addiction, behavioral ecology, neuroeconomics, autism