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...

In this paper I discuss several proposals for how to find out which contents visual experiences have, and I defend the method I.

In the Garden of Eden, we had unmediated contact with the world. We were directly acquainted with objects in the world and with their properties. Objects were simply presented to us without causal mediation, and properties were revealed to us in their true intrinsic glory.

The paper argues that the reference of perceptual demonstratives is fixed in a causal nondescriptive way through the nonconceptual content of perception. That content consists first in spatiotemporal information establishing the existence of a separate persistent object retrieved from a visual scene by the perceptual object segmentation processes that open an object-file for that object. Nonconceptual content also consists in other transducable information, that is, information that is retrieved directly in a bottom-up way from the scene (motion, shape, etc). The (...) nonconceptual content of the mental states induced when one uses a perceptual demonstrative constitutes the mode of presentation of the perceptual demonstrative that individuates but does not identify the object of perceptual awareness and allows reference to it. On that account, perceptual demonstratives put us in a de re relationship with objects in the world through the non-conceptual information retrieved directly from the objects in the environment. (shrink)

In examining the puzzle of experience, and its possible solutions, Valberg discusses relevant views of Hume, Kant, Heidegger, Wittgenstein, and Strawson, as well as ideas from the recent philosophy of perception. Finally, he describes and analyzes a manifestation of the puzzle outside philosophy, in everyday experience.

Consciousness is a mongrel concept: there are a number of very different "consciousnesses." Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of "consciousness" based on (...) the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct "guesses," but they cannot harness this information in the service of action, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are BOTH access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness. (shrink)

John Campbell investigates how consciousness of the world explains our ability to think about the world; how our ability to think about objects we can see depends on our capacity for conscious visual attention to those things. He illuminates classical problems about thought, reference, and experience by looking at the underlying psychological mechanisms on which conscious attention depends.

Over the past fifty years the philosophy of language and mind has been dominated by a nondescriptivist approach to content and reference. This book attempts to recast and systematize that approach by offering an indexical model in terms of mental files. According to Recanati, we refer through mental files, the function of which is to store information derived through certain types of contextual relation the subject bears to objects in his or her environment. The reference of a file is determined (...) relationally, not satisfactionally, so a file is not to be equated to the body of (mis-)information it contains. Mental files are the mental equivalent of singular terms, and the reference of linguistic expressions is inherited from that of the files we associate with them. On this approach, mental files, the vehicles of singular thought, do all the work of so-called 'modes of presentation' in Fregean and neo-Russellian theories. (shrink)

Blindsight and vision for action seem to be exemplars of unconscious visual processes. However, researchers have recently argued that blindsight is not really a kind of uncon- scious vision but is rather severely degraded conscious vision. Morten Overgaard and col- leagues have recently developed new methods for measuring the visibility of visual stimuli. Studies using these methods show that reported clarity of visual stimuli correlates with accuracy in both normal individuals and blindsight patients. Vision for action has also come under (...) scrutiny. Recent findings seem to show that information processed by the dor- sal stream for online action contributes to visual awareness. Some interpret these results as showing that some dorsal stream processes are conscious visual processes (e.g., Gallese, 2007; Jacob & Jeannerod, 2003). The aim of this paper is to provide new support for the more traditional view that blindsight and vision for action are genuinely unconscious per- ceptual processes. I argue that individuals with blindsight do not have access to the kind of purely qualitative color and size information which normal individuals do. So, even though people with blindsight have a kind of cognitive consciousness, visual information process- ing in blindsight patients is not associated with a distinctly visual phenomenology. I argue further that while dorsal stream processing seems to contribute to visual awareness, only information processed by the early dorsal stream (V1, V2, and V3) is broadcast to working memory. Information processed by later parts of the dorsal stream (the parietal lobe) never reaches working memory and hence does not correlate with phenomenal awareness. I con- clude that both blindsight and vision for action are genuinely unconscious visual processes. (shrink)

Milner and Goodale's influential account of the primate cortical visual streams involves a division of consciousness between them, for it is the ventral stream that has the responsibility for visual consciousness. Hence, the dorsal visual stream is a ‘zombie’ stream. In this article, I argue that certain information carried by the dorsal stream likely plays a central role in the egocentric spatial content of experience, especially the experience of visual spatial constancy. Thus, the dorsal stream contributes to a pervasive feature (...) of consciousness. (shrink)

We assemble here in this time and place to discuss the thesis that conscious attention can provide knowledge of reference of perceptual demonstratives. I shall focus my commentary on what this claim means, and on the main argument for it found in the first five chapters of "Reference and Consciousness". The middle term of that argument is an account of what attention does: what its job or function is. There is much that is admirable in this account, and I am (...) confident that it will be the foundation, the launching-pad, for much future work on the subject. But in the end I will argue that Campbell's picture makes the mechanisms of attention too smart: smarter than they are, smarter than they could be. If we come to a more realistic appraisal of the skills and capacities of our sub-personal minions, the "knowledge of reference" which they yield will have to be taken down a notch or two. (shrink)

This paper gives a brief presentation of adverbialism about attention, and explains some of the reasons why it gives an appealing account of attention's metaphysics.

This chapter argues that attention is a distinctive mode of consciousness, which plays an essential functional role in making information accessible for use in the rational control of thought and action. The main line of argument can be stated quite simply. Attention is what makes information fully accessible for use in the rational control of thought and action. But what makes information fully accessible for use in the rational control of thought and action is a distinctive mode of consciousness. Therefore, (...) attention is a distinctive mode of consciousness. In a slogan: attention is rational-access consciousness. (shrink)

Perceptual attention is essential to both thought and agency, for there is arguably no demonstrative thought or bodily action without it. Psychologists and philosophers since William James have taken attention to be a ubiquitous and distinctive form of consciousness, one that leaves a characteristic mark on perceptual experience. As a process of selecting specific perceptual inputs, attention influences the way things perceptually appear. It may then seem that it is a specific feature of perceptual representation that constitutes what it is (...) like to consciously attend to an object. In fact conscious attention is more complicated. In what follows, I argue that the phenomenology of conscious attention to what is perceived involves not just a way of perceptually locking on to a specific object. It necessarily involves a way of cognitively locking on to it as well. (shrink)

I am very much in sympathy with the overall approach of John Campbell’s paper, “Reference as Attention”. My sympathy extends to a variety of its features. I think he is right to suppose, for instance, that neuropsychological cases provide important clues about how we should treat some traditional philosophical problems concerning perception and reference. I also think he is right to suppose that there are subtle but important relations between the phenomena of perception, action, consciousness, attention, and reference. I even (...) think that there is probably something importantly right about the main claim of the paper. I take this to be the claim that there is a tight connection – of some sort at any rate – between our capacity to refer demonstratively to perceptually presented objects and our capacity to attend to those objects in our conscious awareness of them. What precisely this connection consists in, however, remains a mystery to me. My goal in these comments is to clarify this result. I will begin, in section 2, with a fairly general statement of the problem I take Campbell to have set himself. Following this, in section 3, I will focus more particularly on what kind of relation Campbell takes to exist, or does exist, or perhaps could exist between attention and demonstrative reference. I examine four options, the first three of which seem to admit of clear counterexamples, and the fourth of which is too weak to be of any real interest. (shrink)

In this paper I propose a model of demonstrative thought. I distinguish token-demonstratives, that pick out individuals, from type-demonstratives, that pick out kinds, or properties, and provide a similar treatment for both. I argue that it follows from my model of demonstrative thought, as well as from independent considerations, that demonstration, as a mental act, operates directly on mental representations, not external objects. That is, though the relation between a demonstrative and the object or property demonstrated is semantically direct, the (...) mechanism by which a demonstrative acquires its referent involves mediation by a perceptual representation. Finally, I argue that so-called 'demonstrative concepts'—which I treat as type-demonstratives—cannot perform the various philosophical functions that have been assigned to them. (shrink)

In this paper, a theoretical account of the functional role of consciousness in the cognitive system of normal subjects is developed. The account is based upon an approach to consciousness that is drawn from the phenomenological tradition. On this approach, consciousness is essentially peripheral self-awareness, in a sense to be duly explained. It will be argued that the functional role of consciousness, so construed, is to provide the subject with just enough information about her ongoing experience to make it possible (...) for her to easily obtain as much information as she may need. The argument for this account of consciousness' functional role will proceed in three main stages. First, the phenomenological approach to consciousness as peripheral self-awareness will be expounded and endorsed. Second, an account of the functional role of peripheral perceptual awareness will be offered. Finally, the account of the functional role of peripheral self-awareness will be obtained by straightforward extension from the functional role of peripheral perceptual awareness. (shrink)

Block () highlights two experimental studies of neglect patients which, he contends, provide ‘dramatic evidence’ for unconscious seeing. In Block's hands this is the highly non-trivial thesis that seeing of the same fundamental kind as ordinary conscious seeing can occur outside of phenomenal consciousness. Block's case for it provides an excellent opportunity to consider a large body of research on clinical syndromes widely held to evidence unconscious perception. I begin by considering in detail the two studies of neglect to which (...) Block appeals. I show why their interpretation as evidence of unconscious seeing faces a series of local difficulties. I then explain how, even bracketing these issues, a long-standing but overlooked problem concerning our criterion for consciousness problematizes the appeal to both studies. I explain why this problem is especially pressing for Block given his view that phenomenal consciousness overflows access consciousness. I further show that it is epidemic—not only affecting all report-based studies of unconscious seeing in neglect, but also analogous studies of the condition most often alleged to show unconscious seeing, namely blindsight. (shrink)

In "Things and Places," Zenon Pylyshyn argues that the process of incrementally constructing perceptual representations, solving the binding problem (determining which properties go together), and, more generally, grounding perceptual ...

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)

This paper defends and develops the structuring account of conscious attention: attention is the conscious mental process of structuring one’s stream of consciousness so that some parts of it are more central than others. In the first part of the paper, I motivate the structuring account. Drawing on a variety of resources I argue that the phenomenology of attention cannot be fully captured in terms of how the world appears to the subject, as well as against an atomistic conception of (...) attention. In the second part of the paper, I show how the structuring account can be made precise: attention causes and causally sustains phenomenal relations to hold between the parts of the stream of consciousness; most importantly the relation of one part being peripheral to another. I end by pointing out consequences for both the scientific study of attention as well as for several areas of central philosophical interest. (shrink)

Arien Mack and Irvin Rock make the radical claim that there is no conscious perception of the visual world without attention to it.

There seems to be a large gulf between percepts and concepts. In particular, con- cepts seem to be capable of representing things that percepts cannot. We can conceive of things that would be impossible to perceive. (The converse may also seem true, but I will leave that to one side.) In one respect, this is trivially right. We can conceive of things that we cannot encounter, such as unicorns. We cannot literally perceive unicorns, even if we occasionally.

Perception enables us to think demonstrative thoughts about the world around us, but what must perception be like in order to play this role? Does perception enable demonstrative thought only if it is conscious? This paper examines three accounts of the role of consciousness in demonstrative thought, which agree that consciousness is essential for demonstrative thought, but disagree about why it is. First, I consider and reject the accounts proposed by Gareth Evans in The Varieties of Reference and by John (...) Campbell in Reference and Consciousness before offering an alternative proposal of my own. My proposal is that consciousness plays an essential epistemic role in explaining the capacity for demonstrative thought about an object by enabling the subject to form immediately justified beliefs about the object. (shrink)

I argue that there are phenomenological constraints on what it is to see an object, and that these are overlooked by some theories that offer allegedly sufficient causal and counterfactual conditions on object-seeing.

How can we discover the contents of experience? I argue that neither introspection alone nor naturalistic theories of experience content are sufficient to discover these contents. I propose another method of discovery: the method of phenomenal contrast. I defend the method against skeptics who doubt that the contents of experience can be discovered, and I explain how the method may be employed even if one denies that experiences have contents.