The effect of attention on perceived brightness and contrast was investigated in eight experiments. Attention was manipulated by engaging observers in an attention-demanding concurrent task or by directing attention to a location with a peripheral cue. In all of the dual-task manipulations, attention reduced the variability of responses. However, attention did not affect the brightness of stimuli, nor did it affect the amount of simultaneous brightness contrast. Results with peripheral location cues were similar; however, the effect of attention in these (...) experiments could be attributed to nonperceptual factors. The metaphorical “spotlight” of attention reduces observers' uncertainty about the brightness of a stimulus, but it does not “illuminate” in terms of brightness or contrast. (shrink)

Intentionalism is the view that the phenomenal character of a conscious experience is wholly determined by, or even reducible to, its representational content. In this essay I put forward a version of intentionalism that allows (though does not require) the reduction of phenomenal character to representational content. Unlike other reductionist theories, however, it does not require the acceptance of phenomenal externalism (the view that phenomenal character does not supervene on the internal state of the subject). According the view offered here, (...) phenomenal characters essentially represent subject-environment relations that are relevant to the possibilities for causal interaction between the subject and the environment; relations of the kind that J. J. Gibson dubbed affordances. I argue for this view chiefly through an examination of spatial perception, though other cases are also considered. The view assumes that a phenomenal character has an essential functional role; though it need not be assumed that a functional role is sufficient for a phenomenal character. (shrink)

Do we (sometimes) perceive apples as edible? One could argue that it is just a manner of speaking to say so: we do not really see an object as edible, we see it as having certain shape, size and color and we only infer on the basis of these properties that it is. I argue that we do indeed see objects as edible, and do not just believe that they are. My argument proceeds in two steps. First, I point out (...) that Susanna Siegel's influential argument in favor of the claim that we represent sortal properties perceptually does not work. Second, I argue that we can fix this argument if we replace the sortal property in question with the property of being edible, climbable or Q-able in general. (shrink)

I develop a Russellian representationalist account of size experience that draws importantly from contemporary vision science research on size perception. The core view is that size is experienced in ‘body-scaled’ units. So, an object might, say, be experienced as two eye-level units high. The view is sharpened in response to Thompson’s (forthcoming) Doubled Earth example. This example is presented by Thompson as part of an argument for a Fregean view of size experience. But I argue that the Russellian view I (...) develop handles the Doubled Earth example in a natural and illuminating way, thereby avoiding the need to posit irreducible experiential ‘modes of presentation’. I also address a kind of neo-Fregean ‘reference-fixing’ view of size experience, that shares features with the Russellian view developed. I give reasons for favoring the latter. Finally, I argue that Peacocke’s claim that spatial experience is ‘unit free’ is not persuasive. (shrink)

Does attention alter appearance? This critical issue, debated for over a century, remains unsettled. From psychophysical evidence that covert attention affects early vision-it enhances contrast sensitivity and spatial resolution-and from neurophysiological evidence that attention increases the neuronal contrast sensitivity (contrast gain), one could infer that attention changes stimulus appearance. Surprisingly, few studies have directly investigated this issue. Here we developed a psychophysical method to directly assess the phenomenological correlates of attention in humans. We show that attention alters appearance; it boosts (...) the apparent stimulus contrast. These behavioral results are consistent with neurophysiological findings suggesting that attention changes the strength of a stimulus by increasing its 'effective contrast' or salience. (shrink)

Abstract: When I throw a ball at you, do you see it as catch-able? Do we perceive objects as edible, climbable or Q-able in general? One could argue that it is just a manner of speaking to say so: we do not really see an object as edible, we only infer on the basis of its other properties that it is. I argue that whether or not an object is edible or climbable is indeed represented perceptually: we see objects as (...) edible, and do not just believe that they are. My argument proceeds in two steps. First, I argue that in order to perform an action Q with respect to an object, we need to represent this object as Q-able and, second, I argue that we represent objects as having these properties perceptually. (shrink)

Research on attention has evolved dramatically since the early work of the 1950s, and even in the few years since the publication of the first edition of this ...

"Perception is not something that happens to us, or in us," writes Alva Noe. "It is something we do." In Action in Perception, Noe argues that perception and perceptual consciousness depend on capacities for action and thought — that ...

Abstract:When I throw a ball at you, do you see it as catch‐able? Do we perceive objects as edible, climbable or Q‐able in general? One could argue that it is just a manner of speaking to say so: we do not reallyseean object as edible, we only infer on the basis of its other properties that it is. I argue that whether or not an object is edible or climbable is indeed represented perceptually: weseeobjects as edible, and do not just (...) believe that they are. My argument proceeds in two steps. First, I argue that in order to perform an action Q with respect to an object, we need to represent this object as Q‐able and, second, I argue that we represent objects as having these propertiesperceptually. (shrink)

What do we see? We are visually conscious of colors and shapes, but are we also visually conscious of complex properties such as being John Malkovich? In this book, Susanna Siegel develops a framework for understanding the contents of visual experience, and argues that these contents involve all sorts of complex properties. Siegel starts by analyzing the notion of the contents of experience, and by arguing that theorists of all stripes should accept that experiences have contents. She then introduces a (...) method for discovering the contents of experience: the method of phenomenal contrast. This method relies only minimally on introspection, and allows rigorous support for claims about experience. She then applies the method to make the case that we are conscious of many kinds of properties, of all sorts of causal properties, and of many other complex properties. She goes on to use the method to help analyze difficult questions about our consciousness of objects and their role in the contents of experience, and to reconceptualize the distinction between perception and sensation. Siegel's results are important for many areas of philosophy, including the philosophy of mind, epistemology, and the philosophy of science. They are also important for the psychology and cognitive neuroscience of vision. (shrink)

Although the mechanics of how the eye works are well understood, debate still exists as to how the complex machinery of the brain interprets neural impulses...

Introduction: Three key principles -- Sense datum theories -- Adverbial theories -- Belief acquisition theories -- Intentional theories -- Disjunctive theories -- Perception and causation -- Perception and the sciences of the mind -- Perception and other sense modalities.

This is not to say simply that these forms of acting can facilitate representation but that they are themselves representational.

This chapter argues, using the method of phenomenal contrast, that causation is represented in visual experience. The conclusion is contrasted with the conclusions drawn by Michotte in his book The Perception of Causation.

Much of recent philosophy of perception is oriented towards accounting for the phenomenal character of perception—what it is like to perceive—in a non-mentalistic way—that is, without appealing to mental objects or mental qualities. In opposition to such views, I claim that the phenomenal character of perception of a red round object cannot be explained by or reduced to direct awareness of the object, its redness and roundness—or representation of such objects and qualities. Qualities of perception that are not captured by (...) what one is directly aware of or by representational content are instances of what Gilbert Harman has called “mental paint” (Block, 1990; Harman, 1990). The claim of this paper is that empirical facts about attention point in the direction of mental paint. The argument starts with the claim (later modified) that when one moves one's attention around a scene while keeping one's eyes fixed, the phenomenology of perception can change in ways that do not reflect which qualities of objects one is directly aware of or the way the world is represented to be. These changes in the phenomenology of perception cannot be accounted for in terms of awareness of or representation of the focus of attention because they manifest themselves in experience as differences in apparent contrast, apparent color saturation, apparent size, apparent speed, apparent time of occurrence and other appearances. There is a way of coping with these phenomena in terms of vague contents, but vague contents cannot save direct realism or representationism because the kind of vagueness required clashes wth the phenomenology itself. (shrink)

Spatial attention and eye-movements are tightly coupled, but the precise nature of this coupling is controversial. The influential but controversial Premotor theory of attention makes four specific predictions about the relationship between motor preparation and spatial attention. Firstly, spatial attention and motor preparation use the same neural substrates. Secondly, spatial attention is functionally equivalent to planning goal directed actions such as eye-movements (i.e. planning an action is both necessary and sufficient for a shift of spatial attention). Thirdly, planning a goal (...) directed action with any effector system is sufficient to trigger a shift of spatial attention. Fourthly, the eye-movement system has a privileged role in orienting visual spatial attention. This article reviews empirical studies that have tested these predictions. Contrary to predictions one and two there is evidence of anatomical and functional dissociations between endogenous spatial attention and motor preparation. However, there is compelling evidence that exogenous attention is reliant on activation of the oculomotor system. With respect to the third prediction, there is correlational evidence that spatial attention is directed to the endpoint of goal-directed actions but no direct evidence that this attention shift is dependent on motor preparation. The few studies to have directly tested the fourth prediction have produced conflicting results, so the extent to which the oculomotor system has a privileged role in spatial attention remains unclear. Overall, the evidence is not consistent with the view that spatial attention is functionally equivalent to motor preparation so the Premotor theory should be rejected, although a limited version of the Premotor theory in which only exogenous attention is dependent on motor preparation may still be tenable. A plausible alternative account is that activity in the motor system contributes to biased competition between different sensory representations with the winner of the competition becoming the attended item. (shrink)