If you stare for a period of time at a scene which contains movement in one direction, and then turn your attention to an object in a scene which contains no movement, this object will appear to move in the opposite direction to that of the original movement. The effect can be easily achieved by attaching a piece of paper with a spiral drawn on it to the spinning turntable of a record player, and then turning the turntable off while (...) continuing to look at the spiral (see Frisby 1979, pp. 100-101 for a detailed descrip- tion of how to bring this about). But the illusion of movement can also occur when looking at a waterfall, for instance, and turning one's attention away from the waterfall to a stationary object such as a stone; hence its name - the 'Waterfall Illusion'. (shrink)

Can psychology explain the qualitative content of experience? A persistent philosophical objection to that discipline is that it cannot. Qualitative states or 'qualia' are argued to have characteristics which cannot be explained in terms of their relationships to other psychological states, stimuli, and behavior. Since psychology is confined to descriptions of such relationships, it seems that psychology cannot explain qualia. A paradigm case of qualia is provided by simultaneous color contrast effects, in which a neutral grey patch is made to (...) look reddish by being enclosed in a green surround. If the qualia based objections are sound, psychology ought not to be able to explain simultaneous color contrast; but psychology at least seems to be able quite successfully to explain those effects. This paper analyzes the logic of psychological explanations of simultaneous color contrast effects, and the import of various qualia based objections to those explanations. I argue that the qualia objections do not demonstrate any explanatory inadequacy in existing psychological explanations of 'looks'. Psychology succeeds in explaining at least some qualia. In a more positive vein, I argue that once the structure of such explanations is sufficiently understood, a place can be found for qualia within the emerging scientific account of color perception. The resulting account can deal with many of the traditional perplexities over qualia. (shrink)

Executive functioning has been said to bear on a range of traditional philosophical topics, such as consciousness, thought, and action. Surprisingly, philosophers have not much engaged with the scientific literature on executive functioning. This lack of engagement may be due to several influential criticisms of that literature by Daniel Dennett, Alan Allport, and others. In this paper I argue that more recent research on executive functioning shows that these criticisms are no longer valid. The paper clears the way to a (...) more fruitful philosophical engagement with findings on the central executive system. (shrink)

This article compares situated cognition to contemporary Neo-Aristotelian approaches to the mind. The article distinguishes two components in this paradigm: an Aristotelian essentialism which is alien to situated cognition and a Wittgensteinian “capacity approach” to the mind which is not just congenial to it but provides important conceptual and argumentative resources in defending social cognition against orthodox cognitive science. It focuses on a central tenet of that orthodoxy. According to what I call “encephalocentrism,” cognition is primarily or even exclusively a (...) computational process occurring inside the brain. Neo-Aristotelians accuse this claim of committing a “homuncular” or “mereological fallacy”. The article explains why the label “fallacy” is misleading, reconstructs the argument to the effect that encephalocentric applications of psychological predicates to the brain and its parts amount to a category mistake, and defends this argument against objections by Dennett, Searle, and Figdor. At the same time it criticizes the Neo-Aristotelian denial that the brain is the organ of cognition. It ends by suggesting ways in which the capacity approach and situated cognition might be combined to provide a realistic and ecologically sound picture of cognition as a suite of powers that flesh-and-blood animals exercise within their physical and social environments. (shrink)

Often implicit in visual display design and development is a gold standard of photorealism. By approximating direct perception, photorealism appeals to users and designers by being both attractive and apparently effortless. The vexing result from numerous performance evaluations, though, is that increasing realism often impairs performance. Smallman and St. John (2005) labeled misplaced faith in realistic information display Naïve Realism and theorized it resulted from a triplet of folk fallacies about perception. Here, we illustrate issues associated with the wider trend (...) towards realism by focusing on a specific current trend for high-fidelity perspective view (3D) geospatial displays. In two experiments, we validated Naïve Realism for different terrain understanding tasks, explored whether certain individuals are particularly prone to Naïve Realism, and determined the ability of task feedback to mitigate Naïve Realism. Performance was measured for laying and judging a concealed route across realistic terrain shown in different display formats. Task feedback was either implicit, in Experiment 1, or explicit in Experiment 2. Prospective and retrospective intuitions about the best display formats for the tasks were recorded and then related to task performance and participant spatial ability. Participants generally intuited they would perform tasks better with more realism than they actually required. For example, counter to intuitions, lowering fidelity of the terrain display revealed the gross scene layout needed to lay a well-concealed route. Individuals of high spatial ability calibrated their intuitions with only implicit task feedback, whereas those of low spatial ability required salient, explicit feedback to calibrate their intuitions about display realism. Results are discussed in the wider context of applying perceptual science to display design, and combating folk fallacies. (shrink)

There are two main accounts of what it is for external objects to be presented in visual experience. According to particularism, particular objects are built into the representational contents of experiences. Existentialism is a quite different view. According to existentialism, the representational contents of perceptual experiences are general rather than particular, in the sense that the contents can be fully captured by existentially quantified statements. The present paper is a defense of existentialism. It argues that existentialism is much better equipped (...) than particularism to explain the contents of hallucinations, and it defends existentialism against three objections. (shrink)

There are two main accounts of what it is for external objects to be presented in visual experience. According to particularism, particular objects are built into the representational contents of experiences. Existentialism is a quite different view. According to existentialism, the representational contents of perceptual experiences are general rather than particular, in the sense that the contents can be fully captured by existentially quantified statements. The present paper is a defense of existentialism. It argues that existentialism is much better equipped (...) than particularism to explain the contents of hallucinations, and it defends existentialism against three objections. (shrink)

I survey some of the connections between the metaphysics of the relation between mind and matter, and quantum theory’s measurement problem. After discussing the metaphysics, especially the correct formulation of physicalism, I argue that two state-reduction approaches to quantum theory’s measurement problem hold some surprises for philosophers’ discussions of physicalism. Though both approaches are compatible with physicalism, they involve a very different conception of the physical, and of how the physical underpins the mental, from what most philosophers expect. And one (...) approach exemplifies a a problem in the definition of physicalism which the metaphysical literature has discussed only in the abstract. A version of the paper has appeared in Consciousness and Human Identity, ed. John Cornwell, OUP 1998. (shrink)

What is the biological function of perception? I hold perception, especially visual perception in humans, has the biological function of accurately representing the environment. Tyler Burge argues this cannot be so in Origins of Objectivity (Oxford, 2010), for accuracy is a semantical relationship and not, as such, a practical matter. Burge also provides a supporting example. I rebut the argument and the example. Accuracy is sometimes also a practical matter if accuracy partly explains how perception contributes to survival and reproduction.