Today many philosophers of mind accept that the two cortical streams of visual processing in humans can be distinguished in terms of conscious experience. The ventral stream is thought to produce representations that may become conscious, and the dorsal stream is thought to handle unconscious vision for action. Despite a vast literature on the topic of the two streams, there is currently no account of the way in which the relevant empirical evidence could fit with basic Husserlian phenomenology (...) of vision. Here I offer such an account. In this article, I show how the empirical evidence ought to be understood in a way that is informed by phenomenology. The differences in the two streams are better described as differences in spatial and temporal processing. Rather than simply “unconscious,” the dorsal stream can be better described as making a special contribution to what Husserl identified as the visual horizon. (shrink)

David Milner and Melvyn Goodale’s dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action-related “unconscious” stream and a ventral, perception-related “conscious” stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, conscious (...) vision for perception, and unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action (Bruno & Franz, 2009; Dassonville & Bala, 2004; Franz & Gegenfurtner, 2008; McIntosh & Lashley, 2008). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process (Schenk & McIntosh, 2010). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action-guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi-conservative view that the dissociation hypothesis is best understood as a tripartite division. (shrink)

Everyday life suggests that picture seeing is sometimes infused by an emotional charge. However, nobody has addressed the importance of explaining this emotional charge in picture perception. Even our best model of picture perception, the dorsal/ventral account of picture perception, which integrates the most important empirical results coming from our best model on vision in neuroscience, the two visual systems model, lacks a reference to this emotional charge. The aim of the present paper is to offer an account (...) of picture perception that is able to regain and explain this neglected emotional charge. My claim is that, as for face-to-face perception, during picture perception, we are not only in a visual perceptual state, but also in an emotional state, which is directly connected to our visual perceptual state. I also show that it is possible to offer this integration while remaining in the philosophical/empirical framework of the dorsal/ventral account of picture perception, whose explanatory power is confirmed and improved. (shrink)

This paper examines Milner and Goodale’s hypothesis about the two visual streams and raises the questions of whether properties in egocentric space (commonly associated with the vision-for-action, or "dorsal," stream) can be part of the phenomenal content of perceptual experience, or only properties in allocentric space (commonly associated with the vision-for-perception, or "ventral," stream) can play this role, and how (if at all) properties in egocentric space differ from properties in allocentric space. These questions are reminiscent of (...) issues raised by Christopher Peacocke's "equal-sized trees" case: if you are looking at equal-sized trees on the side of a road, the trees will phenomenally look to you to be equally tall. But it is also true that a tree will take up more of the space in your visual field the closer it is to you. So, the equal-sized trees will also phenomenally look to you to have different heights. Your (visual) perceptual experience is not illusory. That is, the trees veridically look to you to have the same height, and they also veridically look to you to have different heights. Call the sort of issue raised here the "problem of dual looks." I provide a solution to the problem of dual looks that helps shed light on whether properties in egocentric space can be part of the phenomenal content of perceptual experience, and how (if at all) properties in egocentric space differ from properties in allocentric space. (shrink)

According to Milner and Goodale’s dual visual systems (DVS) theory, a division obtains between visual consciousness and motor action, in that the visual system producing conscious vision (the ventral stream) is distinct from the one guiding action (the dorsal stream). That there would be this division is often taken (by Andy Clark and others) to undermine the folk view on how consciousness and action relate. However, even if this division obtains, this leaves open the possibility that con- scious (...) ventral information is often transmitted to the uncon- scious dorsal stream and then used to guide action, a possibility seeming to preserve a significant role for consciousness in action. This article assesses this possibility. In course of doing so, we will review those arguments recently having been made against the DVS view on how visual consciousness and action relate (ones due to, e.g., Briscoe and Schwenkler, or Schenk and McIntosh). What we will find is that, if we properly analyze the data upon which these arguments are based, we are still left with the impression that the DVS view is largely correct; i.e., it is only rarely that visual experience guides action. (shrink)

It is natural to assume that the fine-grained and highly accurate spatial information present in visual experience is often used to guide our bodily actions. Yet this assumption has been challenged by proponents of the Two Visual Systems Hypothesis , according to which visuomotor programming is the responsibility of a “zombie” processing stream whose sources of bottom-up spatial information are entirely non-conscious . In many formulations of TVSH, the role of conscious vision in action is limited to “recognizing objects, (...) selecting targets for action, and determining what kinds of action, broadly speaking, to perform” . Our aim in this study is to show that the available evidence not only fails to support this dichotomous view but actually reveals a significant role for conscious vision in motor programming, especially for actions that require deliberate attention. (shrink)

Empirical work and philosophical analysis have led to widespread acceptance that vision for action, served by the cortical dorsal stream, is unconscious. I argue that the empirical argument for this claim is unsound. That argument relies on subjects’ introspective reports. Yet on biological grounds, in light of the theory of primate cortical vision, introspection has no access to dorsal stream mediated visual states. It is thus wrongly assumed that introspective reports speak to absent phenomenology in the (...) dorsal stream. In light of this, I consider a different conception of consciousness’s relation to agency in terms of access. While theoretical reasons suggest that the inaccessibility of the dorsal stream to conceptual report is evidence that it is unconscious, this position begs important questions. I propose a broader notion of access in respect of the guidance of intentional agency and not, narrowly, conceptual report (Note: this paper contradicts my earlier paper, "The Case for Zombie Agency"). (shrink)

The aim of this paper is to argue that action-guiding vision is not cognitively impenetrable and arguments that suggest otherwise rely on an unjustified identification between actionguiding vision and dorsal vision – a functional and an anatomical way of describing the mind. The examination of these arguments show the importance of making a distinction between the functional and the anatomical level when addressing the problem of cognitive penetrability.

Visual systems first evolved not to enable animals to perceive the world, but to provide distal sensory control of their movements. Conscious sight is a relatively recent invention, but its emergence has enabled organisms such as humans and other primates to carry out complex cognitive operations on a detailed perceptual representation of the world. The two streams of visual processing that have been identified in the primate cerebral cortex are a reflection of these two functions of vision. The (...) class='Hi'>dorsal 'action' stream projecting from early visual areas to the posterior parietal cortex mediates the visual control of skilled motor acts. The ventral 'perceptual' stream projecting from early visual areas to the temporal lobe provides a perceptual experience of the world beyond our bodies. Both streams work together in the production of adaptive behavior. (shrink)

Philosophers and neuroscientists often suggest that we perceptually represent objects and their properties. However, they start from very different background assumptions when they use the term “perceptual representation”. On the one hand, sometimes philosophers do not need to properly take into consideration the empirical evidence concerning the neural states subserving the representational perceptual processes they are talking about. On the other hand, neuroscientists do not rely on a meticulous definition of “perceptual representation” when they talk about this empirical evidence that (...) is supposed to show that we perceptually represent such and such properties. It seems that, on both sides, something is missed. My aim is to show that, in the light of empirical evidence from neuroscience, the case of action properties is a good candidate in order to properly talk of perceptually represented properties. My claim is that the neurophysiological states encoding action properties are perceptual processes and that these perceptual processes are representational processes. That is, in the case of those neurophysiological states involved in the detection of action properties, it is correct to speak of perceptual representational states, and hence, ipso facto, of perceptually represented properties. First, I describe a reasonable and widely agreed upon conception of perceptual representation in the philosophical literature. Then, I report evidence from vision and motor neuroscience concerning the perception of action properties, which is subserved by the ventro-dorsal stream, a portion of the dorsal visual system. Finally, I show that a strong connection can be found between the philosophical idea of perceptual representation I have reported before and the neuroscientific evidence concerning the activity of the ventro-dorsal stream, whose job is, as said, to detect action properties. (shrink)

Dijkerman & de Haan (D&dH) propose a convincing model of somatosensory organization that is inspired by earlier perception-action models of the visual system. In this commentary, we suggest that the dorsal and ventral visual streams both contribute to the control of action, but in different ways. Using the example of grip and load force calibration, we show how the ventral stream can invoke stored information about the material properties of objects originally derived from the somatosensory system.

In visual information processing, two kinds of vision are distinguished: vision-for-perception related to the conscious identifi cation of objects, and vision-for-action that deals with visual control of movements. Neuroscience suggests that these two functions are performed by two separate brain neural systems - the ventral and dorsal pathways. Two experiments using behavioural measures were conducted with the objective of exploring any potential interaction between these two functions of vision. The aim was to combine in one (...) task methods allowing for the simultaneous capture of both perceptual global processing and affordance extraction and to check whether they infi uence each other. This aim was achieved by employing the paradigms of Navon and Tucker and Ellis. A compound fi gure was created made up of objects with handles that might or might not have orientation congruent between levels. The results revealed that while the affordance effect occurred every time, the Navon effect appeared only when subjects focused their attention on object elements responsible for inconsistence within compound fi gure. Most importantly, even when these two effects occurred at once, they had no effect on each other. Results from the study failed to confi rm the hypothesis about interaction and gives support to the view that vision-for-perception and vision-for-action tend to act as separate systems. (shrink)

In this book Gerald Vision argues for a new causal theory, one that engages provocatively with direct realism and makes no use of a now discredited subjectivism.

In Veritas, Gerald Vision defends the correspondence theory of truth -- the theory that truth has a direct relationship to reality -- against recent attacks, and critically examines its most influential alternatives. The correspondence theory, if successful, explains one way in which we are cognitively connected to the world; thus, it is claimed, truth -- while relevant to semantics, epistemology, and other studies -- also has significant metaphysical consequences. Although the correspondence theory is widely held today, Vision points (...) to an emerging orthodoxy in philosophy that claims that truth as such carries no significant weight in philosophical explanations. He devotes much of the book to a criticism of that outlook and to a less vulnerable formulation of the correspondence theory.Vision defends the correspondence theory by both presenting evidence for correspondence and examining the claims made by such alternative theories as deflationism, minimalism, and pluralism. The techniques of the argument are thoroughly analytic, but the problem confronted is broadly humanistic. The question examined -- how we, as thinking beings, are connected to and manage to cope in a world that was not designed for our comfort or convenience -- is more likely to be raised by continentalists, but is approached here with the tools of clarity and precision more highly prized in analytic philosophy. The book seeks to avoid both the obscurantism that infects much continental thought and the overly technical concerns and methodology that limit the interest of much work in analytic philosophy. It thus provides a rigorous but largely nontechnical treatment of the topic that will be of interest not only to readers familiar with philosophy but also to those with a background in literary theory and linguistics. (shrink)

In virtue of its form [‘I am here’] must be true on any occasion on which [it is] asserted, and yet the proposition it expresses on each occasion [is] contingent. Intuitively, [‘I am here now’] is deeply, and in some sense universally, true. One need only understand the meaning of [it] to know that it cannot be uttered falsely. The sentence ‘I am here’ has the peculiar property that whenever I utter it, it is bound to be true. Even if (...) I am lost and do not know where I am, I can bravely say ‘I am here’, and know that I am expressing a truth. (shrink)

The evidence of blindsight is occasionally used to argue that we can see things, and thus have perceptual belief, without the distinctive visual awareness accompanying normal sight; thereby displacing phenomenality as a component of the concept of vision. I maintain that arguments to this end typically rely on misconceptions about blindsight and almost always ignore associated visual (or visuomotor) pathologies relevant to the lessons of such cases. More specifically, I conclude, first, that the phenomena very likely do not result (...) from dissociations within a single system, but from the interaction of evolutionarily distinct, if interacting, systems; second, that a closer study of spared motor abilities indicates that verbal responses of patients result not from degraded vision but from proprioception; and, finally, above chance verbal responses, being forced guesses, are not tentative beliefs and cannot become beliefs just by training patients to have more confidence in their responses. (shrink)

I INTRODUCTION - THE TOPIC EXPLAINED 1 GENERAL DIFFERENCES From its inception to the present, philosophy may be viewed as a series of struggles between ...

In " Re-Emergence" he explores the question of conscious properties arising from brute, unthinking matter, making the case that there is no equally plausible non-emergent alternative.

In specifying the sensory evidence for perceptual belief, thinkers have either chosen a common perceptual idiom or have invented one of their own as a starting-point for their enquiries. It is becoming clearer that the choice harbours crucial, often disputable, assumptions. I compare two sorts of constructions, a variety of propositional ones and an objectual one, and I argue that the objectual idiom is indispensable in order to explain how a perceptual belief can arise out of what is not already (...) a belief. This has implications not only for the question of how belief is generated from perceptual evidence, but also for various other controversies. I discuss two of these implications: the character of inferences from evidence, and basic belief. (shrink)

Parmenides didn't mention reference as such, but if he had he would have undoubtedly agreed with the philosophers who nowadays hold what is called "the axiom of existence": that one can only refer to what exists. The sources of possible support for this view are examined and rejected. Primary support for the axiom is given by two sorts of argument; one concerning quantification, the other summarizing a standard Parmenidean puzzle. Weaknesses in both are exposed. Finally, the relations between the axiom (...) and connected claims about predication and truth are probed, and an attempt is made to determine the limits of the mutual support these claims give one another. (shrink)

Parmenides didn't mention reference as such, but if he had he would have undoubtedly agreed with the philosophers who nowadays hold what is called "the axiom of existence": that one can only refer to what exists. The sources of possible support for this view are examined and rejected. Primary support for the axiom is given by two sorts of argument; one concerning quantification, the other summarizing a standard Parmenidean puzzle. Weaknesses in both are exposed. Finally, the relations between the axiom (...) and connected claims about predication and truth are probed, and an attempt is made to determine the limits of the mutual support these claims give one another. (shrink)

Under the title of ‘the axiom of existence’, hereafter, John R. Searle has reduced to compact dictum a view to which many philosophers subscribe: ‘Whatever is referred to must exist’. In this paper I shall offer two major arguments against adopting, at least on certain assumptions. There have been a number of defenses of, among them those arguing that it is fundamental to any systematic philosophy of language or logic. With the exception of discussing some of Searle's remarks in part (...) Ill of this paper I shall not comment on any of these defenses. (shrink)

Although a number of truth theorists have claimed that a deflationary theory of ‘is true’ needs nothing more than the uniform implication of instances of the theorem ‘the proposition that p is true if and only if p ’, reflection shows that this is inadequate. If deflationists can’t support the instances when replacing the biconditional with ‘because’, then their view is in peril. Deflationists sometimes acknowledge this by addressing, occasionally attempting to deflate, ‘because’ and ‘in virtue of’ formulas and their (...) close relatives. I examine what I take to be the most promising deflationist moves in this direction and argue that they fail. (shrink)

From the popular view that the property of truth adds nothing not already inherent in its bearers it has been inferred that classical theories of truth are thereby refuted. Taking as representative a version of deflationism based on a certain way of interpreting the Tarskian schema convention T–and popularly called "disquotational"–I argue that the view is beset by fatal difficulties. These include: an unavoidable awkwardness in handling indexicals; an inability to accept anything more than a too anemic notion of a (...) truth condition, leaving it defenseless against clearly inadequate alternatives; and an incapacity to show that its characteristic biconditional can support any acceptable dependency claims (made evident by replacing the biconditional with 'because'). Finally, were there no predicate on the order of 'is true', this would not annihilate the property of being true or the current grounds for philosophical inquiries about it. This is an important clue to why deflationary approaches in general are dead ends. (shrink)

A broad, though not unanimous, consensus among commentators is that the later Wittgenstein subscribes to a redundancy conception of truth. I reject that interpretation. No doubt much depends on what is meant by a redundancy theory. But once even mildly plausible versions of that view are isolated a review of the relevant texts shows that the evidence for that interpretation collapses. Moreover, the redundancy interpretation is at odds with guiding prescriptions in the post‐1932 corpus. Wittgenstein doesn’t hold that truth can (...) be defined or characterized thinly, as redundancy theorists propose, but that it isn’t susceptible to any such generic treatment. (shrink)

Emergentism is generally viewed as a non‐materialist alternative to physicalism, although the exceptionally tolerant may count it as consistent with their physicalism. It disarms the threat of Causal Exclusion. The popular conception of explored emergentism is played off against two forms, including physical states and tokens of conscious states (c‐states). Emergentism competes not only with physicalism, but also with panpsychism. Panpsychism is the view that all matter has a conscious aspect. Panpsychism (and its various forms) suffers from several problems. This (...) chapter summarizes a few of the major ones. It scratches the surface of the issues separating emergentism and physicalism, on the one hand, and emergentism and panpsychism, on the other. However, perhaps enough has been divulged to show that emergentism is a live option, a serious candidate when trying to discover a c‐state's place in concrete reality. (shrink)

A broad, though not unanimous, consensus among commentators is that the later Wittgenstein subscribes to a redundancy conception of truth. I reject that interpretation. No doubt much depends on what is meant by a redundancy theory. But once even mildly plausible versions of that view are isolated a review of the relevant texts shows that the evidence for that interpretation collapses. Moreover, the redundancy interpretation is at odds with guiding prescriptions in the post‐1932 corpus. Wittgenstein doesn’t hold that truth can (...) be defined or characterized thinly, as redundancy theorists propose, but that it isn’t susceptible to any such generic treatment. (shrink)

A broad, though not unanimous, consensus among commentators is that the later Wittgenstein subscribes to a redundancy conception of truth. I reject that interpretation. No doubt much depends on what is meant by a redundancy theory. But once even mildly plausible versions of that view are isolated a review of the relevant texts shows that the evidence for that interpretation collapses. Moreover, the redundancy interpretation is at odds with guiding prescriptions in the post‐1932 corpus. Wittgenstein doesn’t hold that truth can (...) be defined or characterized thinly, as redundancy theorists propose, but that it isn’t susceptible to any such generic treatment. (shrink)

Some philosophers believe that the doctrine that individuals have (nominal) essences is supported by arguments designed to show that proper names have senses. Three such arguments are extracted from recent pieces of philosophy: one from the absurdity of bare particulars, A second from the necessary conditions for identifying bearers of proper names, And a third from the ability to replace proper names in discourse with the help of sortal terms. All three arguments are rejected upon examination. The bearing this rejection (...) has for our conception of how we identify particulars through time is briefly discussed. Finally, An attempt to revive this sort of essentialism vis-A-Vis semantic categories is criticized. (shrink)

Has Fodor demonstrated conceptual atomism?