The “Perky effect” is the interference of visual imagery with vision. Studies of this effect show that visual imagery has more than symbolic properties, but these properties differ both spatially (including “pictorially”) and temporally from those of vision. We therefore reject both the literal picture-in-the-head view and the entirely symbolic view.

One of the most important issues concerning the foundations ofconscious perception centerson thequestion of whether perceptual consciousness is rich or sparse. The overflow argument uses a form of ‘iconic memory’ toarguethatperceptual consciousnessisricher (i.e.,has a higher capacity) than cognitive access: when observing a complex scene we are conscious of more than we can report or think about. Recently, the overflow argumenthas been challenged both empirically and conceptually. This paper reviews the controversy, arguing that proponents of sparse perception are committed to the (...) postulation of (i) a peculiar kind of generic conscious representation that has no independent rationale and (ii) an unmotivated form of unconscious representation that in some cases conflicts with what we know about unconscious representation. (shrink)

The problem of amodal perception is the problem of how we represent features of perceived objects that are occluded or otherwise hidden from us. Bence Nanay (2010) has recently proposed that we amodally perceive an object's occluded features by imaginatively projecting them into the relevant regions of visual egocentric space. In this paper, I argue that amodal perception is not a single, unitary capacity. Drawing appropriate distinctions reveals amodal perception to be characterized not only by mental imagery, as Nanay suggests, (...) but also by genuinely visual representations as well as beliefs. I conclude with some brief remarks on the role of object-directed bodily action in conferring a sense of unseen presence on an object's occluded features. (shrink)

In this paper, I critically assess the enactive account of visual perception recently defended by Alva Noë (2004). I argue inter alia that the enactive account falsely identifies an object’s apparent shape with its 2D perspectival shape; that it mistakenly assimilates visual shape perception and volumetric object recognition; and that it seriously misrepresents the constitutive role of bodily action in visual awareness. I argue further that noticing an object’s perspectival shape involves a hybrid experience combining both perceptual and imaginative elements (...) – an act of what I call ‘make-perceive.’. (shrink)

The paper argues that the English verb ‘to see’ can denote three different kinds of conscious states of seeing, involving visual experiences, visual seeming states and introspective seeming states, respectively. The case for the claim that there are three kinds of seeing comes from synesthesia and visual imagery. Synesthesia is a relatively rare neurological condition in which stimulation in one sensory or cognitive stream involuntarily leads to associated experiences in a second unstimulated stream. Visual synesthesia is often considered a case (...) of illusory visual experience. This, however, turns out to be a questionable characterization, as there is evidence suggesting that the brain must cognitively process the stimulus in order for the associated synesthetic experience to arise. Furthermore, some very vivid, visual forms of synesthesia do not involve additional processing in the visual cortex. Visual synesthetic experience is likely to be a non-veridical state of seeming rather than an illusory visual experience. Visual seeming states are cognitive states distinct from visual experiences in terms of their representational richness and their neural correlates. Visual seeming states that are non-deviantly causally related to the states of affair they represent constitute a type of non-experiental seeing. Introspective seeming states that are non-deviantly causally related to underlying visual images constitute a second type of non-experiental seeing. The English verb ‘to see’ can denote all three types of seeing, which is to say that ‘to see’ is polysemous. (shrink)

In her response to my "Seeing as a Non-Experiental Mental State: The Case from Synesthesia and Visual Imagery" Ophelia Deroy presents an argument for an interesting new account of synesthesia. On this account, synesthesia can be thought of as "a perceptual state (e.g. of a letter)" that is "changed or enriched by the incorporation of a conscious mental image (e.g. a color)." I reply that while this is a plausible account of some types of synesthesia, some forms cannot be accounted (...) for this way. (shrink)

This paper deals with two theories Husserl worked out on imagery in order to see if the properties a phenomenological description ascribes to imagery are fit to give meaningful constraints upon theoretical models that guide empirical research. Husserlian descriptions and Kosslyn and colleagues models are hence compared as to their explanatory strategy and implications.

To what extent is imagination dependent on embodied experience? In attempting to answer such questions I consider the experiences of those who have to come to terms with altered neurological function, namely those with spinal cord injury at the neck. These people have each lost all sensation and movement below the neck. How might these new ways of living affect their imagination?

At least since Locke, philosophers and psychologists have usually held that concepts arise out of sensory perceptions, thoughts are built from concepts, and language enables speakers to convey their thoughts to hearers. Christopher Gauker holds that this tradition is mistaken about both concepts and language. The mind cannot abstract the building blocks of thoughts from perceptual representations. More generally, we have no account of the origin of concepts that grants them the requisite independence from language. Gauker's alternative is to show (...) that much of cognition consists in thinking by means of mental imagery, without the help of concepts, and that language is a tool by which interlocutors coordinate their actions in pursuit of shared goals. Imagistic cognition supports the acquisition and use of this tool, and when the use of this tool is internalized, it becomes the very medium of conceptual thought. (shrink)

The aim of this article is to expand the diet of examples considered in philosophical discussions of imagination and pretense, and to offer some preliminary observations about what we might learn about the nature of imagination as a result. The article presents a number of cases involving imaginative contagion: cases where merely imagining or pretending that P has effects that we would expect only perceiving or believing that P to have. Examples are offered that involve visual imagery, motor imagery, fictional (...) emotions, and social priming. It is suggested that imaginative contagion is a more prevalent phenomenon than has typically been recognized. (shrink)

Certain simple thoughts about pictures suggest that the contents of pictures are closely bound to vision. But how far can the striking features of depiction be accounted for merely in terms of the especially visual contents which belong to pictures, without considering, for example, any issues concerning the nature of the visual experiences with which pictures provide us? This article addresses that question by providing an account of the distinctively visual contents belonging to pictures, and by using that account to (...) explain many notable general facts about depiction. Some implications of the resulting framework for the main stream of current theorizing about pictorial representation are also discussed. (shrink)

It is clear that visual imagery is somehow significantly visual. Some theorists, like Kosslyn, claim that the visual nature of visualisations derives from features of the neural processes which underlie those episodes. Pylyshyn claims, however, that it may merely reflect special features of the contents which we grasp when we visualise things. This paper discusses and rejects Pylyshyn's own attempts to identify the respects in which the contents of visualisations are notably visual. It then offers a novel and very different (...) account of what is distinctively sensory about the contents of sensory images. The paper's alternative account is used in explaining various pieces of phenomenological and behavioural data concerning visualisation. Finally, it is tentatively suggested that the proposed account of the contents of sensory images may also shed light upon some of the neurological data involving visualisation and sensory imagery more generally. (shrink)

Recent neural models clarify many properties of mental imagery as part of the process whereby bottom-up visual information is influenced by top-down expectations, and how these expectations control visual attention. Volitional signals can transform modulatory top-down signals into supra-threshold imagery. Visual hallucinations can occur when the normal control of these volitional signals is lost.

I have argued elsewhere that imagery and represention are best explained as the result of operations of neurally implemented emulators of an agent's body and environment. In this article I extend the theory of emulation to address perceptual processing as well. The key notion will be that of an emulator of an agent's egocentric behavioral space. This emulator, when run off-line, produces mental imagery, including transformations such as visual image rotations. However, while on-line, it is used to process information from (...) sensory systems, resulting in perception (in this regard, the theory is similar to that proposed by Kosslyn (1994)). This emulator is what provides the theory in theory-laden perception. I close by arguing briefly that the spatial character of perception is to be explained as the contribution of the egocentric behavioral space emulator. (shrink)

What is the relation between affective states, such as emotions and pleasure, and imagining? Do the latter cause the former, just as perceptual states do? Or are the former merely imagined, along with suitable objects? I consider this issue against the backdrop of Sartre’s theory of imagination, and drawing on his highly illuminating discussion of it. I suggest that, while it is commonly assumed that imaginative states cause affective responses much as do perceptions, the alternatives merit more careful consideration than (...) they are usually given. (shrink)

This is a critical notice of Colin McGinn's 'Mindsight'.

Visual imagination (or visualization) is peculiar in being both free, in that what we imagine is up to us, and useful to a wide variety of practical reasoning tasks. How can we rely upon our visualizations in practical reasoning if what we imagine is subject to our whims? The key to answering this puzzle, I argue, is to provide an account of what constrains the sequence in which the representations featured in visualization unfold—an account that is consistent with its freedom. (...) Three different proposals are outlined, building on theories that link visualization to sensorimotor predictive mechanisms (e.g., efference copies, forward models ). Each sees visualization as a kind of reasoning, where its freedom consists in our ability to choose the topic of the reasoning. Of the three options, I argue that the approach many will find most attractive—that visualization is a kind of off-line perception, and is therefore in some sense misrepresentational—should be rejected. The two remaining proposals both conceive of visualization as a form of sensorimotor reasoning that is constitutive of one’s commitments concerning the way certain kinds of visuomotor scenarios unfold. According to the first, these commitments impinge on one’s web of belief from without, in the manner of normal perceptual experience; according to the second, these commitments just are one’s (occurrent) beliefs about such generalizations. I conclude that, despite being initially counterintuitive, the view of visualization as a kind of occurrent belief is the most promising. (shrink)

An overview of the philosophy and psychology of hallucination and its relevance to the philosophy of perception.

AI research concerning the connection between seeing and speaking mainly employs what is called reference semantics. Within this framework, the notion of `mental image' is often used while explaining how somebody not situated in the same perceptual context is able to anchor his understanding of an utterance describing the scene visually perceived by the speaker. We give a foundation for considering mental images as propositions with respect to a certain field of concepts: these fields have to provide a syntactically dense (...) set of concepts distinguishing locations. The use of such propositions in the reference semantic explanations of understanding utterances about visually perceived scenes is motivated by applying Kant's idea of the introduction of new types of objects: we conceive spatial relations as relations only applicable to sortal objects, i.e., individuated objects which are synthetically introduced on a syntactically dense field providing their potential locations. The concept `mental image' which results from these preliminary studies is applied to two current projects in AI, one dealing with the semantics of particular spatial prepositions, and the other more generally concerned with the logic of the connection between visual and verbal space. (shrink)

The cognitive function of mental images with respect to the referential aspect of language is examined and used in the listener model ANTLIMA of the natural language system SOCCER. An operational realization of the reference relation used to recognize instances of spatial concepts in the results of a vision system and also to visualize locative expressions is presented and compared to A. Herskovits' analysis of the semantics of spatial prepositions.

There has been a long tradition of characterizing man as the animal that talks. However, the remarkable ability of using pictures also only belongs to human beings, after all we know empirically so far. Are there conceptual reasons for that coincidence? The paper is dedicated to a philosophical programme of “concept-genetic” considerations dealing in particular with the dependencies between those two abilities: The conceptual relation between the competence to use assertive language and the faculty of employing pictures must be conceived (...) of as being much closer than usually expected. Indeed we conclude, there cannot be creatures with only one of them. (shrink)

The imagery debate re-enacts controversies persisting since Descartes. The controversy remains important less for what we can learn about visual imagery than about cognitive science itself. In the tradition of Arnauld, Reid, Bartlett, Austin and Ryle, Pylyshyn's critique exposes notorious mistakes being unwittingly rehearsed not only regarding imagery but also in several independent domains of research in modern cognitive science.

The term schema (plural: schemata, or sometimes schemas) is widely used in cognitive psychology and the cognitive sciences generally to designate "psychological constructs that are postulated to account for the molar forms of human generic knowledge" (Brewer, 1999). The vagueness of this definition is no accident (and no sort of failing on Brewer's part). In fact schema is used in such very different ways by different cognitive theorists that the term has become quite notorious for its ambiguity (Miller, Polson, & (...) Kintsch, 1984 p. 6). However, a concept of.. (shrink)

To the best of my knowledge, with the exception of Galton's original work (1880, 1883), Sommer's brief case study (1978), and Faw's (1997, 2009) articles, this is the only really substantial discussion of the phenomenon of non-brain-damaged "non-imagers" available anywhere.

A comprehensive theory of the structure and cognitive function of the human imagination, and its relationship to perceptual experience, is developed, largely through a critique of the account propounded in Colin McGinn's Mindsight. McGinn eschews the highly deflationary (and unilluminating) views of imagination common amongst analytical philosophers, but fails to develop his own account satisfactorily because (owing to a scientifically outmoded understanding of visual perception) he draws an excessively sharp, qualitative distinction between imagination and perception (following Wittgenstein, Sartre, and others), (...) and because of his fatally flawed, empirically ungrounded conception of hallucination. In fact, however, an understanding of perception informed by modern visual science will enable us to unify our accounts of perception, mental imagery, dreaming, hallucination, creativity, and other aspects of imagination within a single coherent theoretical framework. (shrink)

Defining Imagery: Experience or Representation?
Historical Development of Ideas about Imagery
Subjective Individual Differences in Imagery Experience
Theories of Imagery, and their Implications for Consciousness
Picture theory
Description theory
Enactive theory.

An introduction to the science and philosophy of mental imagery.

Pylyshyn's critique is powerful. Pictorial theories of imagery fail. On the other hand, the symbolic description theory he manifestly still favors also fails, lacking the semantic foundation necessary to ground imagery's intentionality and consciousness. But, contrary to popular belief, these two theory types do not exhaust available options. Recent work on embodied, active perception supports the alternative perceptual activity theory of imagery.

Since the publication of my "Are Theories of Imagery Theories of Imagination? An _Active Perception_ Approach to Conscious Mental Content," (Thomas, 1999 - henceforth abbreviated as ATOITOI on this page), a good deal of published material has appeared or has come to my attention that either provides additional support for the Perceptual Activity Theory PA theory) of mental imagery presented in ATOITOI, or that throws further doubt on the rival (picture and description) theories that are criticized there. Other relevant evidence (...) was not mentioned in ATOITOI because I lacked the space for a proper explanation of its relevance. I hope eventually to write and publish a new account of

PA

theory, that will make use of much of this material. In the meantime this page provides citations (and, where possible, links) to the "new" support, and discussion sections that briefly explain the relevance of the cited material. Quite apart from presenting new lines of supporting evidence and argument, I hope this page will help to clarify many aspects of. (shrink)

Mental imagery (varieties of which are sometimes colloquially refered to as “visualizing,” “seeing in the mind's eye,” “hearing in the head,” “imagining the feel of,” etc.) is quasi-perceptual experience; it resembles perceptual experience, but occurs in the absence of the appropriate external stimuli. It is also generally understood to bear intentionality (i.e., mental images are always images of something or other), and thereby to function as a form of mental representation. Traditionally, visual mental imagery, the most discussed variety, was thought (...) to be caused by the presence of picturelike representations (mental images) in the mind, soul, or brain, but this is no longer universally accepted. (shrink)

A brief historical and conceptual account of the concept of imagination.

This article defends tradition and common sense against a widespread and rarely questioned contemporary philosophical orthodoxy that underpins the entrenched and exorbitant "lingualism" of so much 20th century thought, and leads the way to extreme doctrines like cognitive relativism and eliminative materialism. It also plugs what might otherwise have seemed to be a significant hole in the argument of my Are Theories of Imagery Theories of Imagination? (which I regard as my main positive contribution so far to the understanding of (...) the mind). For a relatively brief overview of the situation in cognitive theory and consciousness studies, as I see it, see A Stimulus to the Imagination. Click here to view the full article: Imagery and the Coherence of Imagination: a Critique of White. Earlier drafts of this article, one entitled "The White Images of Imagery and Imagination: A Critique and an Alternative", were formerly available on the net. Please make any citations to the published version. - N.J.T.T. (shrink)

This book is a philosopher's examination of the dispute, which raged amongst cognitive psychologists in the 1970s, and has continued to sputter on since, about the nature of mental imagery. As Tye sees things (and, indeed, as the textbooks generally have it) on the one side of the issue we find Stephen Kosslyn and certain close associates, arguing that mental images are best understood on analogy with pictures; and on the other side we find Zenon Pylyshyn, ably seconded by Geoffrey (...) Hinton, arguing that the pictorial analogy is thoroughly misleading, and should be replaced by an analogy to descriptions. Tye's consideration of this debate, attempting to clarify and arbitrate a tangled mess of argument and to explore the implications of what he takes to be the proper outcome, is generally excellent. If you want to understand the strengths of the arguments of Kosslyn, Pylyshyn, and their allies, then this book is to be recommended very warmly. (shrink)

In this article (Part I), I first engage in some conceptual clarification of what the words "imagine," "imagining," and "imagination" can mean. Each has (i) a constructive sense, (ii) an attitudinal sense, and (iii) an imagistic sense. Keeping the senses straight in the course of cognitive theorizing is important for both psychology and philosophy. I then discuss the roles that perceptual memories, beliefs, and genre truth attitudes play in constructive imagination, or the capacity to generate novel representations that go well (...) beyond what's prompted by one's immediate environment. (shrink)

Theories concerning the structure, or format, of mental representation should (1) be formulated in mechanistic, rather than metaphorical terms; (2) do justice to several philosophical intuitions about mental representation; and (3) explain the human capacity to predict the consequences of worldly alterations (i.e., to think before we act). The hypothesis that thinking involves the application of syntax-sensitive inference rules to syntactically structured mental representations has been said to satisfy all three conditions. An alternative hypothesis is that thinking requires the construction (...) and manipulation of the cognitive equivalent of scale models. A reading of this hypothesis is provided that satisfies condition (1) and which, even though it may not fully satisfy condition (2), turns out (in light of the frame problem) to be the only known way to satisfy condition (3). (shrink)

Thought experiments have a mysterious way of informing us about the world, apparently without examining it, yet with a great degree of certainty. It is tempting to try to explain this capacity by making use of the idea that in thought experiments, the mind somehow simulates the processes about which it reaches conclusions. Here, I test this idea. I argue that when they predict the outcomes of hypothetical physical situations, thought experiments cannot simulate physical processes. They use mental models, which (...) should not be confused with process-driven simulations. A convincing case can be made that thought experiments about hypothetical mental processes are mental simulations. Concerning moral thought experiments, I argue that construing them as simulations of mental processes favours certain moral theories over others. The scope of mental simulation in thought experiments is primarily limited by the constraint of relevant similarity on source and target processes: on one hand, this constraint disqualifies thought from simulating external natural processes; on the other hand, it is a source of epistemic bias in moral thought experiments. In view of these results, I conclude that thought experiments and mental simulations cannot be assimilated as means of acquiring knowledge. (shrink)