On the meaning of the question “How fast does time pass?”

In this paper I distinguish interpretations of the question ``How fast does time pass?’’ that are important for the debate over the reality of objective becoming from interpretations that are not. Then I discuss how one theory that incorporates objective becoming—the moving spotlight theory of time—answers this question. It turns out that there are several ways to formulate the moving spotlight theory of time. One formulation says that time passes but it makes no sense to ask how fast; another formulation says that time passes at one second per supersecond; and a third says that time passes at one second per second. I defend the intelligibility of this final version of the theory.     

Inhibitory competition between shape properties in figure-ground perception

Theories of figure-ground perception entail inhibitory competition between either low-level units (edge or feature units) or high-level shape properties. Extant computational models instantiate the 1st type of theory. The authors investigated a prediction of the 2nd type of theory: that shape properties suggested on the ground side of an edge are suppressed when they lose the figure-ground competition. In Experiment 1, the authors present behavioral evidence of the predicted suppression: Object decisions were slower for line drawings that followed silhouettes suggesting portions of objects from the same rather than a different category on their ground sides. In Experiment 2, the authors reversed the silhouette's figure-ground relationships and obtained speeding rather than slowing in the same category condition, thereby demonstrating that the Experiment 1 results reflect suppression of those shape properties that lose the figure-ground competition. These experiments provide the first clear empirical evidence that figure-ground perception entails inhibitory competition between high-level shape properties and demonstrate the need for amendments to existing computational models. Furthermore, these results suggest that figure-ground perception may itself be an instance of biased competition in shape perception.     

Great Expectations: Perceptual Challenges of Visual Surveillance in Lifeguarding

The presence of lifeguards on beaches and at pools has the potential to prevent many drowning incidents. This article examines the visual components of the lifeguard's job, discussing some of the major challenges they face during surveillance. These include optical challenges (turbidity and turbulence of the water, light refraction, and glare), scene challenges (elevated set size affecting clutter and perceptual ‘blindnesses’), stimulus challenges (searching for multiple targets that are complex, dynamic, ill‐defined, and rare), and attentional challenges, including but not limited to vigilance issues. The differences between basic laboratory research and the lifeguarding task are explored, with recommendations for future study. Copyright © 2015 John Wiley & Sons, Ltd.     

Searching for one versus two identical targets: when visual search has a memory

A recent study has suggested that observers' visual explorations of the external world can proceed unimpaired when the visual environment precludes the operation of memory processes (as, for instance, when the display elements change locations every 100 ms). One theoretical limitation of this study was that distractors were the only elements that had the potential to be tagged during visual search. The present study sought to clarify the amnesic-search hypothesis by investigating whether memory processes can guide search in other contexts in which targets also have the potential to be tagged. Accordingly, the experimental conditions of the previous study were repeated using a different search task in which observers had to decide whether one target or two were present among a variable number of similar distractors. Under these search conditions, the present findings provided strong evidence that memory processes can guide visual search.     

Are shapes intrinsic?

It is widely believed that shapes are intrinsic properties. But this claim is hard to defend. I survey all known theories of shape properties, and argue that each theory is either incompatible with the claim that shapes are intrinsic, or can be shown to be false.     

The Tenseless Theory of Time and the Moodless Theory of Modality

This paper develops a moodless theory of modality, intended to be as closely analogous to the tenseless theory of time as possible. It is argued that the new theory is distinct from David Lewis' modal realism and that it solves certain problems better than modal realism does, namely, the problem of advanced modalizing, the problem of necessitism, and the problem of conflict with common opinion.     

Some thoughts on Experiencing Time

This paper examples several arguments from Simon Prosser's book Experiencing Time. His argument against the doctrine of the specious present is applauded. His argument that even if time passes, nothing can detect the passage of time, is questioned. Also challenged are his claims that our experience represents things as enduring, rather than perduring, and represents things as having contradictory properties.