Tested the 2-process theory of detection, search, and attention presented by the current authors in a series of experiments. The studies demonstrate the qualitative difference between 2 modes of information processing: automatic detection and controlled search; trace the course of the learning of automatic detection, of categories, and of automatic-attention responses; and show the dependence of automatic detection on attending responses and demonstrate how such responses interrupt controlled processing and interfere with the focusing of attention. The learning of categories is (...) shown to improve controlled search performance. A general framework for human information processing is proposed. The framework emphasizes the roles of automatic and controlled processing. The theory is compared to and contrasted with extant models of search and attention. (shrink)

Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to general cognition. This paper sets out some of the arguments for both sides and defends the position that an important part of visual perception, which may be called early vision or just vision, is prohibited from accessing relevant expectations, knowledge and utilities - in other words it (...) is cognitively impenetrable. That part of vision is complex and articulated and provides a representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues, including the use of signal detection theory and event-related potentials to assess cognitive penetration of vision. A distinction is made among several stages in visual processing. These include, in addition to the inflexible early-vision stage, a pre-perceptual attention allocation stage and a post-perceptual evaluation, memory-accessing, and inference stage which provide several different highly constrained ways in which cognition can affect the outcome of visual perception. The paper discusses arguments that have been presented in both computer vision and psychology showing that vision is "intelligent" and involves elements of problem solving". It is suggested that these cases do not show cognitive penetration, but rather they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect. (shrink)

Can the phenomenal character of perceptual experience be altered by the states of one's cognitive system, for example, one's thoughts or beliefs? If one thinks that this can happen then one thinks that there can be cognitive penetration of perceptual experience; otherwise, one thinks that perceptual experience is cognitively impenetrable. I claim that there is one alleged case of cognitive penetration that cannot be explained away by the standard strategies one can typically use to explain away alleged cases. The case (...) is one in which it seems subjects' beliefs about the typical colour of objects affects their colour experience. I propose a two-step mechanism of indirect cognitive penetration that explains how cognitive penetration may occur. I show that there is independent evidence that each step in this process can occur. I suspect that people who are opposed to the idea that perceptual experience is cognitively penetrable will be less opposed to the idea when they come to consider this indirect mechanism and that those who are generally sympathetic to the idea of cognitive penetrability will welcome the elucidation of this plausible mechanism. (shrink)

The doctrine that the character of our perceptual knowledge is plastic, and can vary substantially with the theories embraced by the perceiver, has been criticized in a recent paper by Fodor. His arguments are based on certain experimental facts and theoretical approaches in cognitive psychology. My aim in this paper is threefold: to show that Fodor's views on the impenetrability of perceptual processing do not secure a theory-neutral foundation for knowledge; to show that his views on impenetrability are almost certainly (...) false; and to provide some additional arguments for, and illustrations of, the theoretical character of all observation judgments. (shrink)

I argue that perceptual content is always affected by the allocation of one’s attention. Perception attributes determinable and determinate properties to the perceived scene. Attention makes (or tries to make) our perceptual attribution of properties more determinate. Hence, a change in our attention changes the determinacy of the properties attributed to the perceived scene.

In this paper, I argue that visual attention is cognitively penetrated by intention. I present a detailed account of attention and its neural basis, drawing on a recent computational model of neural modulation during attention: divisive normalization. I argue that intention shifts computations during divisive normalization. The epistemic consequences of attentional bias are discussed.

Churchland's paper "Perceptual Plasticity and Theoretical Neutrality" offers empirical, semantical and epistemological arguments intended to show that the cognitive impenetrability of perception "does not establish a theory-neutral foundation for knowledge" and that the psychological account of perceptual encapsulation that I set forth in The Modularity of Mind "[is] almost certainly false". The present paper considers these arguments in detail and dismisses them.

I argue that when perception plays a guiding role in intentional bodily action, it is a necessary part of that action. The argument begins with a challenge that necessarily arises for embodied agents, what I call the Many-Many Problem. The Problem is named after its most common case where agents face too many perceptual inputs and too many possible behavioral outputs. Action requires a solution to the Many-Many Problem by selection of a specific linkage between input and output. In bodily (...) action the agent perceptually selects, and in this way perceptually attends to, relevant information so as to guide the execution of specific movements. Since perceptual attention is a necessary part of solving the Many-Many Problem, it is a necessary part of bodily action. Indeed, the process of implementing a solution to the Many-Many Problem, as constrained by the agent's motivational state, just is the agent's performing an intentional bodily action in the relevant way. (shrink)

Is color experience cognitively penetrable? Some philosophers have recently argued that it is. In this paper, we take issue with the claim that color experience is cognitively penetrable. We argue that the notion of cognitive penetration that has recently dominated the literature is flawed since it fails to distinguish between the modulation of perceptual content by non-perceptual principles and genuine cognitive penetration. We use this distinction to show that studies suggesting that color experience can be modulated by factors of the (...) cognitive system do not establish that color experience is cognitively penetrable. Additionally, we argue that even if color experience turns out to be modulated by color-related beliefs and knowledge beyond non-perceptual principles, it does not follow that color experience is cognitively penetrable since the experiences of determinate hues involve post-perceptual processes. We conclude with a brief discussion of the implications that these ideas may have on debates in philosophy. (shrink)

Cognitive penetration of perception, broadly understood, is the influence that the cognitive system has on a perceptual system. The paper shows a form of cognitive penetration in the visual system which I call ‘architectural’. Architectural cognitive penetration is the process whereby the behaviour or the structure of the perceptual system is influenced by the cognitive system, which consequently may have an impact on the content of the perceptual experience. I scrutinize a study in perceptual learning that provides empirical evidence that (...) cognitive influences in the visual system produce neural reorganization in the primary visual cortex. The type of cognitive penetration can be synchronic and diachronic. (shrink)

The question of whether cognition can influence perception has a long history in neuroscience and philosophy. Here, we outline a novel approach to this issue, arguing that it should be viewed within the framework of top-down information-processing. This approach leads to a reversal of the standard explanatory order of the cognitive penetration debate: we suggest studying top-down processing at various levels without preconceptions of perception or cognition. Once a clear picture has emerged about which processes have influences on those at (...) lower levels, we can re-address the extent to which they should be considered perceptual or cognitive. Using top-down processing within the visual system as a model for higher-level influences, we argue that the current evidence indicates clear constraints on top-down influences at all stages of information processing; it does, however, not support the notion of a boundary between specific types of information-processing as proposed by the cognitive impenetrability hypothesis. (shrink)

Wayne Wu argues that attention is necessary for action: since action requires a solution to the ‘Many–Many Problem’, and since only attention can solve the Many–Many Problem, attention is necessary for action. We question the first of these two steps and argue that it is based on an oversimplified distinction between actions and reflexes. We argue for a more complex typology of behaviours where one important category is action that does not require a solution to the Many–Many Problem, and so (...) does not require attention. (shrink)

I elaborate on Pylyshyn's definition of the cognitive impenetrability (CI) of early vision, and draw on the role of concepts in perceptual processing, which links the problem of the CI or cognitive penetrability (CP) of early vision with the problem of the nonconceptual content (NCC) of perception. I explain, first, the sense in which the content of early vision is CI and I argue that if some content is CI, it is conceptually encapsulated, that is, it is NCC. Then, I (...) examine the definitions of NCC and argue that they lead to the view that the NCC of perception is retrieved in a stage of visual processing that is CI. Thus, the CI of a state and content is a sufficient and necessary condition for the state and its content to be purely NCC, the CI?≡?NCC thesis. Since early vision is CI, the purely NCC of perception is formed in early vision. I defend the CI?≡?NCC thesis by arguing against objections raised against both the sufficient and the necessary part of the thesis. (shrink)

Traditional theories of associative learning have found no place for the possibility that the way in which events are perceived might change as a result of experience. Evidence for the reality of perceptual learning has come from those studied by learning theorists. The work reviewed in this book shows that learned changes in perceptual organization can in fact be demonstrated, even in experiments using procedures of the type on which associative theories have been based. These results come from procedures that (...) have been the focus of detailed theoretical and empirical analysis; and from this analysis emerges an outline of the mechanisms responsible. Some of these are themselves associative; others require the addition of nonassociative mechanisms to the traditional theory. The result is an extended version of associative theory which, it is argued, will be relevant not only to the experimental procedures discussed in this book but to the entire range of instances of perceptual learning. (shrink)

More than one third of the human brain is devoted to the processes of seeing - vision is after all the main way in which we gather information about the world. But human vision is a dynamic process during which the eyes continually sample the environment. Where most books on vision consider it as a passive activity, this book is unique in focusing on vision as an 'active' process. It goes beyond most accounts of vision where the focus is on (...) seeing, to provide an integrated account of seeing AND looking. The book starts by pointing out the weaknesses in our traditional approaches to vision and the reason we need this new approach. It then gives a thorough description of basic details of the visual and oculomotor systems necessary to understand active vision. The book goes on to show how this approach can give a new perspective on visual attention, and how the approach has progressed in the areas of visual orienting, reading, visual search, scene perception and neuropsychology. Finally, the book summarises progress by showing how this approach sheds new light on the old problem of how we maintain perception of a stable visual world. Written by two leading vision scientists, this book will be valuable for vision researchers and psychology students, from undergraduate level upwards. (shrink)

In recent years, Bayesian probability theory has emerged not only as a powerful tool for building computational theories of vision, but also as a general paradigm for studying human visual perception. This book provides an introduction to and critical analysis of the Bayesian paradigm. Leading researchers in computer vision and experimental vision science describe general theoretical frameworks for modeling vision, detailed applications to specific problems and implications for experimental studies of human perception. The book provides a dialogue between different perspectives (...) both within chapters, which draw on insights from experimental and computational work, and between chapters, through commentaries written by the contributors on each other's work. Students and researchers in cognitive and visual science will find much to interest them in this thought-provoking collection. (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)

This book provides a foundation to the principles of psychology. It draws upon the natural sciences, avoiding metaphysics, for the basis of its information. According to James, this book, assuming that thoughts and feelings exist and are vehicles of knowledge, thereupon contends that psychology, when it has ascertained the empirical correlation of the various sorts of thought or feeling with definite conditions of the brain, can go no farther as a natural science.

This review focuses on how covert attention modulates perception. It explains why attention is considered a selective process, the constructs of covert attention, and spatial endogenous and exogenous attention. This review includes the effects of spatial attention on discriminability and appearance in tasks mediated by contrast sensitivity and spatial resolution.