This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)
It is argued that seeing that P is a mode of knowing that P that is to be explained in terms of the exercise of visual-perceptual recognitional abilities. The nature of those abilities is described. The justification for believing that P, when one sees that P, is provided by the fact that one sees that P. Access to this fact is explained in terms of an ability to recognize of seen objects that one is seeing them. Reasons for resistance to (...) such an account are considered. The distinction between merely reasonable belief and well-founded belief is emphasised. (shrink)
Many of Margaret Cavendish’s criticisms of Thomas Hobbes in the Philosophical Letters (1664) relate to the disorder and damage that she holds would result if Hobbesian pressure were the cause of visual perception. In this paper, I argue that her “two men” thought experiment in Letter IV is aimed at a different goal: to show the explanatory potency of her account. First, I connect Cavendish’s view of visual perception as “patterning” to the “two men” thought experiment in Letter (...) IV. Second, I provide a potential reply on Hobbes’s behalf that appeals to physiological differences between perceivers’ sense organs, drawing upon Hobbes’s optics in De homine. Third, I argue that such a reply would misunderstand Cavendish’s objective of showing the limited explanatory resources available in understanding visual perception as pressing when compared to her view of visual perception as patterning. (shrink)
This thesis falls into two parts, a characterizing part, and an explanatory part. In the first part, I outline some of the core aspects of our ordinary understanding of visual perception, and how we regard it as a means of knowing. What explains the fact that I know that the lemon before me is yellow is my visual perception: I know that the lemon is yellow because I can see it. Some explanations of how one knows specify that (...) in virtue of which one genuinely knows, as opposed to merely believes, some content. Such explanations are epistemically satisfactory explanations. We think that visual perceptual explanations of knowledge can be epistemically satisfactory. I argue that that is what it is to regard visual perception as being among our means of knowing. In the second part, I explore how we might explain the fact that visual perception is a means of knowing (assuming that it is a fact). I ask what makes it the case that visual perception is a means of knowing (in the way we ordinarily think that it is)? I suggest that part of the answer to this question is that visual perception, given the nature it has, has a reason giving role. And that is just to say that the nature of visual perception is such that visually perceiving can ensure the satisfaction of some important condition on knowledge (namely, that if one knows that something is the case one must have a good reason to believe that it is the case). In concluding I suggest that giving this sort of explanation doesn't require a specific theory of perception. (shrink)
Since its publication fifty years ago, this work has established itself as a classic. It casts the visual process in psychological terms and describes the creative way one's eye organizes visual material according to specific psychological premises. In 1974 this book was revised and expanded, and since then it has continued to burnish Rudolf Arnheim's reputation as a groundbreaking theoretician in the fields of art and psychology.
In his ecological approach to perception, James Gibson introduced the concept of affordance to refer to the perceived meaning of environmental objects and events. this paper examines the relational and causal character of affordances, as well as the grounds for extending affordances beyond environmental features with transcultural meaning to include those features with culturally-specific meaning. such an extension is seen as warranted once affordances are grounded in an intentional analysis of perception. toward this end, aspects of merleau-ponty's treatment (...) of perception are explored. finally, a resolution of the apparent tension between the relational and perceiver-independent nature of affordances is presented. (shrink)
In Remarks on the philosophy of psychology Wittgenstein uses ambiguous illusions to investigate the problematic relation of perception and interpretation. I use this problem as a starting point for developing a conceptual framework capable of expressing problems associated with visual perception in a precise manner. I do this by discerning between subjective and objective meaning of the term “to see” and by specifying the beliefs which are to be ascribed to the observer when we assert that she sees (...) a given object. The framework (detailed in section 2) is then used to analyze the case of the duck/rabbit illusion. It shows that ambiguous illusions present us with a specific skeptical challenge but that the challenge can be overcome by empirical sciences. Along the way I explicate some of the common notions associated with perception (“to look at”, “to have an impression of…”, "to react as if one had an impression of..”, “to convince oneself that what one sees is…”). (shrink)
Three case studies offered here will support the conclusion that a successful scientific theory of visual cognition still makes room for some rather systematic and rather striking semantic indeterminacies-W.V. Quine's well-known pessimism about the wages of such indeterminacy not withstanding. The first case concerns the perception of shape, the second concerns color vision, and the third concerns the rules of inference involved in "unconscious inference" within the visual system.
O'Regan & Noë mistakenly identify visual processing with visual experience. I outline some reasons why this is a mistake, taking my data and arguments mainly from the literature on subliminal processing.
Neuroscience studies show many examples of very early modulation of visual cortex responses. It is argued that such early routing is essential for a rapid processing of information by the visual system.
Understanding how activity in the brain leads to a subjective percept is of great interest to philosophers and neuroscientists alike. In the last years, neurophysiological experiments have approached this problem directly by measuring neural signals in animals as they experience well-defined visual percepts. Stimuli in these studies are often inherently ambiguous, and thus rely upon the subjective report, generally from trained monkeys, to provide a measure of perception. By correlating activity levels in the brain to this report, one can (...) speculate on the role of individual neurons and groups of neurons in the formation and maintenance of a particular percept. However, in order to draw valid conclusions from such experiments, it is critical that the responses accurately and reliably reflect what is perceived. For this reason, a number of behavioural paradigms have been developed to control and evaluate the truthfulness of responses from behaving animals. Here we describe several approaches to optimizing the reliability of a monkey's perceptual report, and argue that their combination provides an invaluable approach in the study of subjective visual perception. (shrink)
Fodor & Pylyshyn (1981) criticize J. J. Gibson's ecological account of perception for failing to address what I call the 'correlation problem' in visual perception. That is, they charge that Gibson cannot explain how perceivers learn to correlate detectable properties of the light with perceptible properties of the environment. Furthermore, they identify the correlation problem as a crucial issue for any theory of visual perception, what I call a 'primary problem'—i.e. a problem which plays a definitive role (...) in establishing the concerns of a particular scientific research program. If they are correct, Gibson's failure to resolve this problem would cast considerable doubt upon his ecological approach to perception. In response, I argue that both Fodor & Pylyshyn's problem itself and their proposed inferential solution embody a significant mistake which needs to be eliminated from our thinking about visual perception. As part of my response, I also suggest a Gibsonian alternative to Fodor & Pylyshyn's primary problem formulation. (shrink)
Standard models of visual perception hold that vision is an inferential or interpretative process. Such models are said to be superior to competing, non-inferential views in explanatory power. In particular, they are said to be capable of explaining a number of otherwise mysterious, visual phenomena such as multi-stable perception. Multi-stable perception paradigmatically occurs in the presence of ambiguous figures, single images that can give rise to two or more distinct percepts. Different interpretations are said to produce the (...) different percepts. In this paper, I argue that a non-inferential account of visual perception is just as capable of explaining multi-stable perception. I propose an embedded understanding of vision, and show how the embedded account can, after properly qualifying them, use the explanatory resources of the inferential view to explain just what such a view explains. (shrink)
I set out two theses. The first is Lynn Robertson’s: (a) spatial awareness is a cause of object perception. A natural counterpoint is: (b) spatial awareness is a cause of your ability to make accurate verbal reports about a perceived object. Zenon Pylyshyn has criticized both. I argue that nonetheless, the burden of the evidence supports both (a) and (b). Finally, I argue conscious visual perception of an object has a different causal role to both: (i) non-conscious (...) class='Hi'>perception of the object, and (ii) experience, e.g. hallucination, that may be subjectively indiscriminable from, but is not, perception of the object. (shrink)
We examine a number of investigations of perceptual economy or, more specifically, of minimum tendencies and minimum principles in the visual perception of form, depth, and motion. A minimum tendency is a psychophysical finding that perception tends toward simplicity, as measured in accordance with a specified metric. A minimum principle is a theoretical construct imputed to the visual system to explain minimum tendencies. After examining a number of studies of perceptual economy, we embark on a systematic analysis of (...) this notion. We examine the notion that simple perceptual representations must be defined within the "geometric constraints" provided by proximal stimulation. We then take up metrics of simplicity. Any study of perceptual economy must use a metric of simplicity; the choice of metric may be seen as a matter of convention, or it may have deep theoretical and empirical implications. We evaluate several answers to the question of why the visual system might favor economical representations. Finally, we examine several accounts of the process for achieving perceptual economy, concluding that those which favor massively parallel processing are the most plausible. (shrink)
We analyse the way in which the principle that ‘the whole is greater than the sum of its parts’ manifests itself with phenomena of visual perception. For this investigation we use insights and techniques coming from quantum cognition, and more specifically we are inspired by the correspondence of this principle with the phenomenon of the conjunction effect in human cognition. We identify entities of meaning within artefacts of visual perception and rely on how such entities are modelled for (...) corpuses of texts such as the webpages of the World-Wide Web for our study of how they appear in phenomena of visual perception. We identify concretely the conjunction effect in visual artefacts and analyse its structure in the example of a photograph. We also analyse quantum entanglement between different aspects of meaning in artefacts of visual perception. We confirm its presence by showing that well elected experiments on images retrieved accordingly by Google Images give rise to probabilities and expectation values violating the Clauser Horne Shimony Holt version of Bell’s inequalities. We point out how this approach can lead to a mathematical description of the meaning content of a visual artefact such as a photograph. (shrink)
In this paper I present a transcendental argument based on the findings of cognitive psychology and neurophysiology which invites two conclusions: First and foremost, that a pre-condition of visual perception itself is precisely what the Aristotelian and other commonsense realists maintain, namely, the independent existence of a featured, or pre-packaged world; second, this finding, combined with other reflections, suggests that, contra McDowell and other neo-Kantians, human beings have access to things as they are in the world via non-projective (...) class='Hi'>perception. These two conclusions taken together form the basis of Aristotelian metaphysical realism and a refutation of the neo-Kantian two-factor approach to perception. (shrink)
Schizophrenia is associated with a series of visual perception impairments, which might impact on the patients’ every day life and be related to clinical symptoms. However, the heterogeneity of the visual disorders make it a challenge to understand both the mechanisms and the consequences of these impairments, i.e., the way patients experience the outer world. Based on earlier psychiatry literature, we argue that issues regarding time might shed a new light on the disorders observed in patients with schizophrenia.We will (...) briefly review the mechanisms involved in the sense of time continuity and clinical evidence that they are impaired in patients with schizophrenia.We will then summarize a recent experimental approach regarding the coding of time-event structure in time, namely the ability to discriminate between simultaneous and asynchronous events. The use of an original method of analysis allowed us to distinguish between explicit and implicit judgments of synchrony.We showed that for SOAs below 20ms neither patients nor controls fuse events in time. On the contrary subjects distinguish events at an implicit level even when judging them as synchronous. In addition, the implicit responses of patients and controls differ qualitatively. It is as if controls always put more weight on the last occurred event, whereas patients have a difficulty to follow events in time at an implicit level. In patients, there is a clear dissociation between results at short and large asynchronies, that suggest selective mechanisms for the implicit coding of time-event structure. These results might explain the disruption of the sense of time continuity in patients.We argue that this line of research might also help us to better understand the mechanisms of the visual impairments in patients and how they see their environment. (shrink)